Prevalenza delle infezioni (aprile 2003 - aprile 2012)


Legionella species in year-round vs. seasonal accommodation water supply systems

Rakić A, Perić J, Štambuk-Giljanović N, Mikrut A, Bakavić AS.

Public Health Institute of Split, Split, Croatia.

Arh Hig Rada Toksikol. 2011 Dec 1;62(4):335-40.

ABSTRACT: The purpose of this study was to compare the quality of hot water between eleven hotels in the Split-Dalmatia County, Croatia that are open year round and 10 summer season hotels and retirement homes with irregular use of water. We took 122 samples between May and December 2009. Water temperature and free residual chlorine were measured in situ. Physical and chemical analysis included pH, electrical conductivity, and concentrations of iron, manganese, copper, zinc, calcium, and magnesium that were measured using atomic absorption spectrophotometry, while the Legionella species were determined using a cultivation method on buffered charcoal yeast extract agar. Differences in metal concentrations between the seasonal and year-round accommodation facilities were negligible, save for zinc that was higher in year-round (0.341 mg L(-1)) than in seasonal facilities (0.130 mg L(-1)). Samples from all year-round and six summer season hotels were negative to the Legionella species, but four seasonal facilities turned up with positive samples to Legionella pneumophila. Our study has demonstrated that water quality differs between year-round and seasonal accommodation facilities. These findings suggest that metal plumbing components and associated corrosion products are important factors in the survival and growth of Legionella species in water distribution systems.


Increase of cases of legionellosis in Latvia, 2011

Rozentale B, Bormane A, Perevosčikovs J, Lucenko I, Brila A.

State Agency Infectology Center of Latvia, Latvia.

Euro Surveill. 2011 Nov 10;16(45).

ABSTRACT: An increased number of legionellosis cases in 2011 has been reported in Latvia, compared to the ten previous years. A total of 30 legionellosis cases (1.35 per 100,000 inhabitants), including 19 females, have been confirmed until the end of September 2011. The majority of cases (n=23) were inhabitants of the capital city Riga. The reason for the increase in legionellosis is unclear. Twenty-six of the 30 cases are not travel-related.


Changing epidemiological trends of legionellosis in New Zealand, 1979-2009

Graham FF, White PS, Harte DJ, Kingham SP.

GeoHealth Laboratory, Department of Geography, University of Canterbury, Christchurch, New Zealand.

Epidemiol Infect. 2011 Sep 27:1-16.

ABSTRACT: SUMMARY This study evaluated the spatio-temporal variation of Legionella spp. in New Zealand using notification and laboratory surveillance data from 1979 to 2009 and analysed the epidemiological trends. To achieve this we focused on changing incidence rates and occurrence of different species over this time. We also examined whether demographic characteristics such as ethnicity may be related to incidence. The annual incidence rate for laboratory-proven cases was 2·5/100 000 and 1·4/100 000 for notified cases. Incidence was highest in the European population and showed large geographical variations between 21 District Health Boards. An important finding of this study is that the predominant Legionella species causing disease in New Zealand differs from that found in other developed countries, with about 30-50% of cases due to L. longbeachae and a similar percentage due to L. pneumophila for any given year. The environmental risk exposure was identified in 420 (52%) cases, of which 58% were attributed to contact with compost; travel was much less significant as a risk factor (6·5%). This suggests that legionellosis has a distinctive epidemiological pattern in New Zealand.


Surveillance for waterborne disease outbreaks associated with drinking water---United States, 2007—2008

Brunkard JM, Ailes E, Roberts VA, Hill V, Hilborn ED, Craun GF, Rajasingham A, Kahler A, Garrison L, Hicks L, Carpenter J, Wade TJ, Beach MJ, Yoder Msw JS.

Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, CDC.

MMWR Surveill Summ. 2011 Sep 23;60(12):38-68.

ABSTRACT: Problem/Condition: Since 1971, CDC, the Environmental Protection Agency (EPA), and the Council of State and Territorial Epidemiologists have collaborated on the Waterborne Disease and Outbreak Surveillance System (WBDOSS) for collecting and reporting data related to occurrences and causes of waterborne disease outbreaks associated with drinking water. This surveillance system is the primary source of data concerning the scope and health effects of waterborne disease outbreaks in the United States. Reporting Period: Data presented summarize 48 outbreaks that occurred during January 2007--December 2008 and 70 previously unreported outbreaks. Description of System: WBDOSS includes data on outbreaks associated with drinking water, recreational water, water not intended for drinking (WNID) (excluding recreational water), and water use of unknown intent (WUI). Public health agencies in the states, U.S. territories, localities, and Freely Associated States are primarily responsible for detecting and investigating outbreaks and reporting them voluntarily to CDC by a standard form. Only data on outbreaks associated with drinking water, WNID (excluding recreational water), and WUI are summarized in this report. Outbreaks associated with recreational water are reported separately. Results: A total of 24 states and Puerto Rico reported 48 outbreaks that occurred during 2007--2008. Of these 48 outbreaks, 36 were associated with drinking water, eight with WNID, and four with WUI. The 36 drinking water--associated outbreaks caused illness among at least 4,128 persons and were linked to three deaths. Etiologic agents were identified in 32 (88.9%) of the 36 drinking water--associated outbreaks; 21 (58.3%) outbreaks were associated with bacteria, five (13.9%) with viruses, three (8.3%) with parasites, one (2.8%) with a chemical, one (2.8%) with both bacteria and viruses, and one (2.8%) with both bacteria and parasites. Four outbreaks (11.1%) had unidentified etiologies. Of the 36 drinking water--associated outbreaks, 22 (61.1%) were outbreaks of acute gastrointestinal illness (AGI), 12 (33.3%) were outbreaks of acute respiratory illness (ARI), one (2.8%) was an outbreak associated with skin irritation, and one (2.8%) was an outbreak of hepatitis. All outbreaks of ARI were caused by Legionella spp. A total of 37 deficiencies were identified in the 36 outbreaks associated with drinking water. Of the 37 deficiencies, 22 (59.5%) involved contamination at or in the source water, treatment facility, or distribution system; 13 (35.1%) occurred at points not under the jurisdiction of a water utility; and two (5.4%) had unknown/insufficient deficiency information. Among the 21 outbreaks associated with source water, treatment, or distribution system deficiencies, 13 (61.9%) were associated with untreated ground water, six (28.6%) with treatment deficiencies, one (4.8%) with a distribution system deficiency, and one (4.8%) with both a treatment and a distribution system deficiency. No outbreaks were associated with untreated surface water. Of the 21 outbreaks, 16 (76.2%) occurred in public water systems (drinking water systems under the jurisdiction of EPA regulations and water utility management), and five (23.8%) outbreaks occurred in individual systems (all of which were associated with untreated ground water). Among the 13 outbreaks with deficiencies not under the jurisdiction of a water system, 12 (92.3%) were associated with the growth of Legionella spp. in the drinking water system, and one (7.7%) was associated with a plumbing deficiency. In the two outbreaks with unknown deficiencies, one was associated with a public water supply, and the other was associated with commercially bottled water. The 70 previously unreported outbreaks included 69 Legionella outbreaks during 1973--2000 that were not reportable previously to WBDOSS and one previously unreported outbreak from 2002. Interpretation: More than half of the drinking water--associated outbreaks reported during the 2007--2008 surveillance period were associated with untreated or inadequately treated ground water, indicating that contamination of ground water remains a public health problem. The majority of these outbreaks occurred in public water systems that are subject to EPA's new Ground Water Rule (GWR), which requires the majority of community water systems to complete initial sanitary surveys by 2012. The GWR focuses on identification of deficiencies, protection of wells and springs from contamination, and providing disinfection when necessary to protect against bacterial and viral agents. In addition, several drinking water--associated outbreaks that were related to contaminated ground water appeared to occur in systems that were potentially under the influence of surface water. Future efforts to collect data systematically on contributing factors associated with drinking water outbreaks and deficiencies, including identification of ground water under the direct influence of surface water and the criteria used for their classification, would be useful to better assess risks associated with ground water. During 2007--2008, Legionella was the most frequently reported etiology among drinking water--associated outbreaks, following the pattern observed since it was first included in WBDOSS in 2001. However, six (50%) of the 12 drinking water--associated Legionella outbreaks were reported from one state, highlighting the substantial variance in outbreak detection and reporting across states and territories. The addition of published and CDC-investigated legionellosis outbreaks to the WBDOSS database clarifies that Legionella is not a new public health issue. During 2009, Legionella was added to EPA's Contaminant Candidate List for the first time. Public Health Actions: CDC and EPA use WBDOSS surveillance data to identify the types of etiologic agents, deficiencies, water systems, and sources associated with waterborne disease outbreaks and to evaluate the adequacy of current technologies and practices for providing safe drinking water. Surveillance data also are used to establish research priorities, which can lead to improved water quality regulation development. Approximately two thirds of the outbreaks associated with untreated ground water reported during the 2007--2008 surveillance period occurred in public water systems. When fully implemented, the GWR that was promulgated in 2006 is expected to result in decreases in ground water outbreaks, similar to the decreases observed in surface water outbreaks after enactment of the Surface Water Treatment Rule in 1974 and its subsequent amendments. One third of drinking water--associated outbreaks occurred in building premise plumbing systems outside the jurisdiction of water utility management and EPA regulations; Legionella spp. accounted for >90% of these outbreaks, indicating that greater attention is needed to reduce the risk for legionellosis in building plumbing systems. Finally, a large communitywide drinking water outbreak occurred in 2008 in a public water system associated with a distribution system deficiency, underscoring the importance of maintaining and upgrading drinking water distribution system infrastructure to provide safe water and protect public health.


How often is a work-up for Legionella pursued in patients with pneumonia? A retrospective study

Hollenbeck B, Dupont I, Mermel LA.

Department of Epidemiology and Infection Control, Rhode Island Hospital, 593 Eddy Street, Providence RI 02903 USA.

BMC Infect Dis. 2011 Sep 7;11:237.

ABSTRACT: BACKGROUND: It is unclear how often patients with pneumonia are assessed for Legionella in endemic areas. Additionally, the sensitivity of the IDSA/ATS criteria for recommended Legionella testing is undefined. METHODS: We performed a single-center, retrospective study of patients diagnosed with Legionella pneumonia at our hospital to determine: 1) how often Legionella diagnostic testing is obtained on patients with pneumonia at the time of hospitalization or when pneumonia developed during hospitalization; and 2) how often patient's with Legionella pneumonia met at least one of the five criteria in the IDSA/ATS guidelines recommending a work-up for Legionella. Patients with Legionella pneumonia were identified using an infection control software program. Medical records of these patients were then reviewed. RESULTS: Thirty-five percent of patients with a discharge diagnosis of pneumonia had Legionella urine antigen testing and/or a Legionella culture performed. Forty-four percent of patients who had a bronchoscopic specimen sent for microbiologic testing had a Legionella culture performed on the bronchoscopic specimen and/or Legionella urine antigen testing. Of 37 adult patients with Legionella pneumonia, 22 (59%) met the IDSA-ATS criteria recommending Legionella testing. CONCLUSION: Following current recommendations for Legionella testing missed 41% of Legionella cases in adults in our single-center study. A work-up for Legionella (i.e., urine antigen test and/or culture) was performed in less than half of patients who have a bronchoscopic specimen sent for microbiologic testing.


Legionellosis United States, 2000-2009

Centers for Disease Control and Prevention (CDC).

MMWR Morb Mortal Wkly Rep. 2011 Aug 19;60(32):1083-6.

ABSTRACT: Legionnaires disease (LD), a serious, sometimes lethal pneumonia, and Pontiac fever (PF), an influenza-like, self-limited illness, are the two most common forms of legionellosis, which is caused by Legionella bacteria. Legionellosis cases are reported to CDC through the National Notifiable Disease Surveillance System (NNDSS) and a Supplemental Legionnaires Disease Surveillance System (SLDSS) designed to manage surveillance data on travel-related cases and enhance outbreak detection. For this report, cases reported to NNDSS during 2000-2009 from the 50 states and the District of Columbia (DC) were assessed, and crude and age-adjusted incidence rates per 100,000 persons were calculated. U.S. legionellosis cases reported annually increased 217%, from 1,110 in 2000 to 3,522 in 2009, and the crude national incidence rate increased 192%, from 0.39 per 100,000 persons in 2000 to 1.15 in 2009. Because NNDSS is a passive surveillance system dependent on health-care providers and laboratories reporting cases, the actual incidence of legionellosis in the United States likely is higher. Although NNDSS does not record legionellosis cases by type, 99.5% of the legionellosis cases reported to SLDSS during 2005-2009 were classified as LD and 0.5% as PF. Legionellosis surveillance was added to the population-based Active Bacterial Core surveillance (ABCs) system in January 2011 to assess reasons for these increases in numbers of reported cases. The rise in reported cases reinforces the need for health-care providers in all parts of the United States to test and treat adults with severe community-acquired pneumonia for LD, to be vigilant for health-care--associated LD, and to report legionellosis cases to public health authorities.


Pontiac fever among retirement home nurses associated with airborne legionella

Hautemaniere A, Remen T, Mathieu L, Deloge-Abarkan M, Hartemann P, Zmirou-Navier D.

Nancy University -- School of Medicine, Vandoeuvre-les-Nancy, France.

J Hosp Infect. 2011 Aug;78(4):269-73.

ABSTRACT: The aim of this study was to ascertain incidence of symptoms compatible with Pontiac fever (PF) and to assess their association with exposure to legionella bacteria among retirement home nurses who help residents take their shower. Within a non-epidemic framework, 104 nurses of 19 retirement homes were followed up during an average period of four months. Data on symptoms, number and location of showers they attended were recorded daily by each participant. Water and aerosol bacterial quality was characterised at the end of follow-up using the culturable and the in-situ hybridisation techniques. Among 11 Pontiac-like episodes, eight cases complied with the study definition of PF. Water concentrations >10(3) cfu legionella per litre were associated with an increased risk of PF, with dose-response patterns. No association was established between the aerosol legionella concentrations and PF events. A threshold value of 103 cfu legionella per litre of water might be used with a view to protection from legionella-associated occupational conditions.


Epidemiology and control of legionellosis, Singapore

Lam MC, Ang LW, Tan AL, James L, Goh KT.

Ministry of Health, Singapore.

Emerg Infect Dis. 2011 Jul;17(7):1209-15.

ABSTRACT: To determine trends and clinical and epidemiologic features of legionellosis in Singapore, we studied cases reported during 2000-2009. During this period, 238 indigenous and 33 imported cases of legionellosis were reported. Cases were reported individually and sporadically throughout each year. Although the annual incidence of indigenous cases had decreased from 0.46 cases per 100,000 population in 2003 to 0.16 cases per 100,000 in 2009, the proportion of imported cases increased correspondingly from 6.2% during 2000-2004 to 27.3% during 2005-2009 (p<0.0005). The prevalence of Legionella bacteria in cooling towers and water fountains was stable (range 12.1%-15.3%) during 2004-August 2008.


Legionella infections and travel associated legionellosis

Guyard C, Low DE.

Ontario Agency for Health Protection and Promotion (OAHPP), 81 resources Road, Toronto, Ontario, M9P 3T1, Canada.

Travel Med Infect Dis. 2011 Jul;9(4):176-86.

ABSTRACT: Travel associated Legionnaires' disease represents a significant cause of travel associated respiratory tract infections and impacts disproportionately on otherwise healthy individuals as a consequence of their travel abroad or within their own country. Because of the propensity of these bacteria to colonize man-made water systems, legionellosis are frequently reported in travelers who stayed in accommodations sites such as hotels or cruise ships. Since the discovery of this new pathogen and the creation of surveillance networks, the number of reported travel associated legionellosis cases have increased regularly. Education of physicians about the association of Legionnaires' disease with travel and the use of appropriate diagnostic tests and therapy can result in a reduction in morbidity and mortality due to this important cause of community-acquired pneumonia.


Environmental surveillance and molecular characterization of Legionella in tropical Singapore

Lim YH, Relus Kek YL, Lim PY, Yap HM, Vivien Goh TL, Ng LC.

Environmental Health Institute, National Environment Agency, Singapore, 11 Biopolis Way #06-05/08 Helios Block Singapore 138667.

Trop Biomed. 2011 Apr; 28(1):149-59.

ABSTRACT: Legionnaires' disease is often acquired by inhalation of legionellae from a contaminated environmental source. In recent years, Singapore has seen an increase in the use of aerosol-generating fixtures such as mist fans and spa pools. Poorly maintained and designed water fixtures could pose a public health threat to the community. In this study, we provided an update on the prevalence of Legionella in mist fans (N=28), household water heaters with storage tanks (N=19) and instantaneous heaters (N=30); and extended the survey to spa pools (N=29) and aerosol-generating fixtures in nursing homes (N=116). The prevalence of Legionella were 21.1% in water heaters with storage tanks, 24.1% in spa pools, 14.2% in mist fans and 3.3% in instantaneous heaters. Legionella was not detected in nursing homes. A total of 37 isolates were subjected to molecular characterization using Sequence-Based Typing (SBT) protocol from the European Working Group on Legionella Infections (EWGLI). This is the first study on the use of SBT protocol on environmental strains isolated from tropical South East Asia. The Legionella flora was very heterogenous. The overall diversity of the allelic profile was found to be 0.970 (95% CI 0.946 - 0.994). All known STs of our isolates have been associated with clinical cases in EWGLI database. The phylogenetic analysis showed that our novel environmental isolates were clustered with clinical STs that were previously reported in Europe, Japan, United Kingdom and United States etc. (in EWGLI database), suggesting that Legionella found in the environment of Singapore may potentially cause human disease.


Legionella: from protozoa to humans

Buchrieser C.

Institut Pasteur, Biologie des Bactéries Intracellulaires and CNRS URA 2171 Paris, France.

Front Microbiol. 2011;2:182.



Progress in the surveillance and control of Legionella infection in France, 1998-2008

Campese C, Bitar D, Jarraud S, Maine C, Forey F, Etienne J, Desenclos JC, Saura C, Che D.

Institut de Veille Sanitaire, 12 rue du Val d'Osne, 94415 Saint Maurice Cedex, France.

Int J Infect Dis. 2011 Jan;15(1):e30-7.

ABSTRACT: BACKGROUND: In France, the notification of Legionnaires' disease (LD) has been mandatory since 1987. Following a study showing an important under-reporting of the disease, the surveillance system was strengthened in 1997: the urinary antigen detection test was introduced as a new diagnostic tool and guidelines for prevention and control of the disease were implemented. After these measures, the incidence of LD increased gradually, reaching 2.5 per 100000 in 2005, and then slightly decreased (2.0 per 100000 in 2008). METHODS: Data from the mandatory notification system and from the national reference centre for Legionella were analysed. Analysis covered the 1998-2008 period. RESULTS: During the period 1998-2008 a total of 11147 cases of LD were reported in France through the mandatory system. The majority of cases were diagnosed by urinary antigen test. The median age of cases was 61 years, the male to female ratio was 2.9, and the case fatality rate was 13%. Exposure during travel was documented for 17% of cases. A hospital-acquired infection was suspected for 9% of cases, and this percentage decreased from 21% in 1998 to 7% in 2008. Over this period, 14 community outbreaks were identified involving 380 cases, and cooling towers were the most probable source of infection for 13. No outbreak was reported in 2008. Registration at the regional level of all cooling towers became mandatory at the end of 2004, and the 1997 prevention and control guidelines were updated in 2005. In recent years, several regulations have also been implemented in the hospital setting and care homes for the elderly. CONCLUSION: All these measures have contributed to strengthen the French surveillance system and improve our ability to better prevent, detect, and control LD.


Legionella spp. and legionellosis in southeastern Italy: disease epidemiology and environmental surveillance in community and health care facilities

Napoli C, Fasano F, Iatta R, Barbuti G, Cuna T, Montagna MT.

Department of Biomedical Science and Human Oncology - Hygiene section, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy.

BMC Public Health. 2010 Nov 2;10:660.

ABSTRACT: BACKGROUND: Following the publication of the Italian Guidelines for the control and prevention of legionellosis an environmental and clinical surveillance has been carried out in Southeastern Italy. The aim of the study is to identify the risk factors for the disease, so allowing better programming of the necessary prevention measures. METHODS: During the period January 2000 - December 2009 the environmental surveillance was carried out by water sampling of 129 health care facilities (73 public and 56 private hospitals) and 533 buildings within the community (63 private apartments, 305 hotels, 19 offices, 4 churches, 116 gyms, 3 swimming pools and 23 schools). Water sampling and microbiological analysis were carried out following the Italian Guidelines. From January 2005, all facilities were subject to risk analysis through the use of a standardized report; the results were classified as good (G), medium (M) and bad (B). As well, all the clinical surveillance forms for legionellosis, which must be compiled by physicians and sent to the Regional Centre for Epidemiology (OER), were analyzed. RESULTS: Legionella spp. was found in 102 (79.1%) health care facilities and in 238 (44.7%) community buildings. The percentages for the contamination levels < 1,000, 1,000-10,000, > 10,000 cfu/L were respectively 33.1%, 53.4% and 13.5% for samples from health care facilities and 33.5%, 43.3% and 23.2% for samples from the community. Both in hospital and community environments, Legionella pneumophila serogroup (L. pn sg) 2-14 was the most frequently isolate (respectively 54.8% and 40.8% of positive samples), followed by L. pn sg 1 (respectively 31.3% and 33%). The study showed a significant association between M or B score at the risk analysis and Legionella spp. positive microbiological test results (p < 0.001). From clinical surveillance, during the period January 2001 - August 2009, 97 cases of legionellosis were reported to the OER: 88 of community origin and 9 nosocomial. The most frequent symptoms were: fever (93.8%), cough (70.1%), dyspnea (58.8%), shivering (56.7%). Radiological evidence of pneumonia was reported in 68%. The laboratory diagnostic methods used were: urinary antigen (54.3%), single antibody titer (19.8%), only seroconversion (11.1%), other diagnostic methods (14.8%). CONCLUSIONS: Our experience suggests that risk analysis and environmental microbiological surveillance should be carried out more frequently to control the environmental spread of Legionella spp. Furthermore, the laboratory diagnosis of legionellosis cannot be excluded only on the basis of a single negative test: some patients were positive to only one of the diagnostic tests.


Travel-associated Legionnaires disease in Europe in 2009

Joseph CA, Ricketts KD, Yadav R, Patel S; European Working Group for Legionella Infections.

Centre for Infections, Health Protection Agency, London, United Kingdom.

Euro Surveill. 2010 Oct 14;15(41):19683.

ABSTRACT: A total of 818 cases of Legionnaires' disease with onset of illness in 2009 were reported from 22 European and two non-European countries to the European Surveillance Scheme for Travel-Associated Legionnaires' Disease (EWGLINET). This is a decrease of 52 cases compared with 2008 and 129 fewer than in 2007 - the peak year of reporting to date. A total of 794 (97.1%) cases were reported as confirmed and 24 as presumptive cases. Outcome of illness was reported for 561 (68.6%) cases. Of these cases 28 (5%) were reported to have died. More than half, of the cases in 2009 (n=469, 57.3%) were reported within 20 days of symptom onset. Cases visited 53 countries and were infected in all months of the year, with a peak in September (n=146). By country of residence of the cases, the United Kingdom (UK) reported the highest number of cases (n=173). Italy reported the second highest number of cases (n=169) and was also the country associated with the most cases by country of infection (n=209). A total of 88 new clusters (75 in Europe and 13 outside Europe) were detected in 2009 and were associated with 196 cases. The largest cluster occurred in Italy and involved seven cases. Without the scheme's international database, thirty three (37.5%) of the newly detected clusters would not have been identified. In 49 of the accommodation sites with clusters of cases, environmental samples were found to be positive for Legionella spp. Details of 10 sites were published on the European Working Group for Legionella Infections (EWGLI) website for failure to return information on the status of environmental investigations.


Characteristics of reoffending accommodation sites in Europe with clusters of Legionnaires disease, 2003-2007

Ricketts KD, Yadav R, Rota MC, Joseph CA; European Working Group for Legionella Infections.

Respiratory Diseases Department, Health Protection Agency, Centre for Infections, London, United Kingdom.

Euro Surveill. 2010 Oct 7;15(40). pii: 19680.

ABSTRACT: Between 2003 and 2007, 21% (n=100/477) of accommodation sites linked to clusters of two or more cases of Legionnaires’ disease that were investigated by the European Surveillance Scheme for Travel-Associated Legionnaires’ Disease (EWGLINET) went on to be associated with at least one further case, despite reporting that satisfactory control measures had been implemented at the time the cluster was first detected. This paper examines these sites (termed reoffenders) in order to determine whether they share any characteristics that may have contributed to the reoffence. All investigations conducted at cluster sites between 2003 and 2007 were included in the analysis, giving a total of 615 investigations conducted at 477 sites. Every country that investigated more than three cluster sites had to deal with at least one reoffence, and one site reoffended five times. The cases involved in the cluster that stayed elsewhere during their incubation periods could be used to help assess the probability of exposure, and therefore the risk, posed by particular cluster sites. A more extensive investigation and control regime may be needed in some instances to better control the risk of Legionnaires’ disease at an accommodation site.


Travel-associated Legionnaires disease in Europe in 2008

Ricketts K, Joseph CA, Yadav R; European Working Group for Legionella Infections.

Respiratory Diseases Department, Health Protection Agency Centre for Infections, London, United Kingdom.

Euro Surveill. 2010 May 27;15(21):19578.

ABSTRACT: In 2008, the European Surveillance Scheme for Travel Associated Legionnaires Disease (EWGLINET) received reports of 866 cases of travel-associated Legionnaires disease, 42 of whom were reported to have died. 824 of the cases were classified as confirmed and 42 were presumptive. As in previous years, a very low proportion of clinical isolates were obtained (63 cases, 7.3%). Males outnumbered females by 2.8:1 in the 2008 dataset and had a median age of 60 years compared with women, whose median age was 63 years. Travel outside Europe was reported for 12% of the cases. The scheme identified 108 new clusters in 2008. Sixteen were located in countries outside EWGLINET and 38 (35.2%) involved only one case from each reporting country, and would not ordinarily have been detected by national surveillance schemes alone. The largest cluster (six cases) was associated with travel to Spain. The 108 clusters were associated with 144 environmental investigations, 35 of which were at re-offending sites, (sites which had previously been investigated and where additional cases had subsequently occurred). At 61 (42.1%) of the sites Legionella species were detected. The names of 12 sites were published on the EWGLINET website.


Legionnaires disease in Europe 2007-2008

Joseph CA, Ricketts KD, European Working Group for Legionella Infections.

Respiratory Diseases Department, Health Protection Agency Centre for Infections, London.

Euro Surveill. 2010 Feb 25;15(8):19493.

ABSTRACT: Each spring, countries that participate in the European Surveillance Scheme for Travel Associated Legionnaires Disease (EWGLINET) are requested to submit their annual dataset of all cases of Legionnaires disease in residents of their country with onset of illness in the preceding year. These data have been collected annually since 1994 and are used to analyse epidemiological and microbiological trends within and between countries over time. This paper presents an overview of the data collected for 2007 and 2008. A total of 5,907 cases were reported by 33 countries in 2007 and 5,960 cases by 34 countries in 2008, a similar two-year total to that recorded in 2005 and 2006 [1]. The only countries with a major difference in case numbers between 2007 and 2008 were Russia, due to a large outbreak in 2007, and Italy where cases increased by 256 in 2008 mainly due to an increase in community-acquired infections. The 779 reported deaths give a two-year case fatality rate of 6.6%. Some 243 outbreaks or clusters were detected, 150 of which were linked to travel-associated infections. As in previous years, the overall main method of diagnosis was by urinary antigen detection and the proportion of cases diagnosed by culture remained low at 8.8%, although isolation rates by country ranged from under 1% to over 40%.


Legionella pneumophila monoclonal antibody subgroups and DNA sequence types isolated in Canada between 1981 and 2009: Laboratory Component of National Surveillance

Reimer AR, Au S, Schindle S, Bernard KA.

Special Bacteriology, Emerging Bacterial Pathogens Division, National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg R3E 3R2, Canada.

Eur J Clin Microbiol Infect Dis. 2010 Feb;29(2):191-205.

ABSTRACT: Legionella pneumophila (Lp) is a significant cause of nosocomial, community-acquired, and travel-associated pneumonia in industrialized regions. Legionellosis has been a nationally notifiable disease in Canada since 1986, with an average of 75 cases reported annually; however, only the most severe, and often fatal, cases are reported or investigated. Here, epidemiological relationships, types, and distribution of Lp referrals to the Canadian national reference center were studied. Lp strains from different years, sources, and geographic locations were subtyped using a sequence-based typing (SBT) scheme and by the 'Joly' and/or 'Dresden' monoclonal antibody panels. Included were 128 epidemiologically unrelated clinical and 86 unrelated environmental strains. Sixty-four (index of diversity [IOD] = 0.964) and 45 (IOD = 0.888) sequence types (STs) were observed among clinical and environmental sources, respectively. Serogroup (sg) 1 was represented by 60.2% (77/128) and 52.3% (45/86) of clinical and environmental strains, respectively, and 63.6% (49/77) and 15.6% (7/45) of those were mAb2-positive, respectively. Serogroup 1, ST1 accounted for 14.1% (18/128) and 30.2% (26/86) of unrelated clinical and environmental isolates, respectively. This database will serve as a basis for Canadian epidemiological surveillance efforts and is linked to global surveillance initiatives curated by the European Working Group for Legionella Infections (EWGLI) network.


Legionella antibodies in a danish hospital staff with known occupational exposure

Rudbeck M, Viskum S, Mølbak K, Uldum SA.

Department of Bacteriology, Mycology, and Parasitology, Statens Serum Institut, DK-2300 Copenhagen, Denmark.

J Environ Public Health. 2009;2009:812829.

ABSTRACT: Although legionnaires' disease frequently is acquired in health care institutions, little is known about the occupational risk of Legionella infection among health care workers. The aim of the present cross-sectional study was to analyse antibody levels among exposed hospital workers and to determine the correlation between antibodies to Legionella and self-reported symptoms. The study included 258 hospital employees and a reference group of 708 healthy blood donors. Hospital workers had a higher prevalence of Legionella antibody titres (>/=1 : 128) than blood donors (odds ratio 3.4; 95% CI 2.4-4.8). Antibody levels were not higher among staff members at risk of frequent aerosol exposure than among less exposed employees. There was no consistent association between a history of influenza-like symptom complex and the presence of antibodies. The results indicate that hospital workers have a higher risk of Legionella infections than the general population. However, since no excess morbidity was associated with seropositivity, most Legionella infections may be asymptomatic.


Dynamics of Legionella antibody levels during 1 year in a healthy population

Rudbeck M, Mølbak K, Uldum SA.

Department of Bacteriology, Statens Serum Institut, Copenhagen, Denmark.

Epidemiol Infect. 2009 Jul;137(7):1013-8.

ABSTRACT: A total of 522 Danish blood donors were followed during 2004-2005 to describe the seroepidemiology of Legionella infections in healthy individuals from a general population. Antibodies to Legionella spp. were measured by indirect immunofluorescence antibody test. The prevalence of Legionella antibodies (titre 1:128) was 26.8% and remained fairly constant during the year of follow-up. However, 6.9% of the blood donors developed a fourfold or greater rise in antibody titres. A history of visits to Danish summer cottages was associated with both Legionella seropositivity (OR 1.53, 95% CI 1.02-2.30) and seroconversion (OR 2.66, 95% CI 1.21-5.83). There were no consistent associations between either levels of antibody titres or seroconversion and self-reported health symptoms, absence from work due to illness, or to any risk factors. We conclude that community-acquired Legionella infections are frequent; however, they rarely result in severe illness.


Distribution of Legionella pneumophila serogroups, monoclonal antibody subgroups and DNA sequence types in recent clinical and environmental isolates from England and Wales (2000-2008)

Harrison TG, Afshar B, Doshi N, Fry NK, Lee JV.

Respiratory and Systemic Infections Department, HPA Centre for Infections, 61 Colindale Avenue, London, NW9 5HT, UK.

Eur J Clin Microbiol Infect Dis. 2009 Jul;28(7):781-91.

ABSTRACT: Clinical isolates of Legionella pneumophila, obtained from 167 patients, who acquired their illness in the community in England and Wales between January 2000 and March 2008, were compared with 276 environmental isolates of L. pneumophila obtained over the same period as part of the routine sampling of 'managed' water systems. The 443 isolates were typed by monoclonal antibody (mAb) subgrouping and the internationally standardised, seven-gene loci, sequence-based typing (SBT) scheme of the European Working Group for Legionella Infections (EWGLI). Of the clinical isolates, 97.6% were L. pneumophila serogroup (sgp) 1, compared with only 55.8% of environmental isolates (P = 0.0002); 91.6% were subgrouped as mAb3/1+ve, compared with only 8.3% of environmental isolates (P < 0.0001). The isolates were very diverse, with SBT identifying 111 sequence types (STs) (index of diversity [IOD] 0.954). Among the clinical isolates, 42 ST were seen, with one (ST47) accounting for 25.7% and three (ST47, ST37 and ST62) accounting for 46.1% of all isolates. Eighty-two STs were identified among the environmental isolates, with two (ST1 and ST79) accounting for 34.1% of these. Comparison of the STs seen among clinical and environmental isolates showed that there was very little overlap between the two populations (P < 0.0001), with common clinical strains found in the environment very infrequently: 0.4, 0.7 and 0% (ST47, ST37 and ST62, respectively), and common environmental strains rarely causing disease: 4.8 and 1.2% (ST1 and ST79, respectively). Combining phenotypic and genotypic data identified 144 phenons (IOD 0.970); 52 among clinical isolates and 101 among environmental isolates. The most abundant clinical strain, mAb 'Allentown' ST47, accounted for 22.8% of cases, but was only found once in the environment. Conversely, mAb 'Oxford/OLDA' ST1 was the most common environmental strain (17.0%), but only caused two infections. A review of the published data shows that mAb 'Allentown' ST47 is also an important cause of infection in France and possibly in the Netherlands. However, it was not found in a large study of German clinical isolates. This study confirms previous work showing that just a few strains of L. pneumophila cause the majority of community-acquired Legionella infection in England and Wales, and that these clinically significant strains are only rarely found in managed water systems. These data suggest that knowing which particular strain is present in an environment might be at least as important as knowing the quantity in which legionellae are present.


Laboratory-based evaluation of legionellosis epidemiology in Ontario, Canada, 1978 to 2006

Ng V, Tang P, Jamieson F, Guyard C, Low DE, Fisman DN.

Child Health Evaluative Sciences, Research Institute of the Hospital for Sick Children, Toronto, Canada.

BMC Infect Dis. 2009 May 21;9:68.

ABSTRACT: BACKGROUND: Legionellosis is a common cause of severe community acquired pneumonia and respiratory disease outbreaks. The Ontario Public Health Laboratory (OPHL) has conducted most testing for Legionella species in the Canadian province of Ontario since 1978, and represents a multi-decade repository of population-based data on legionellosis epidemiology. We sought to provide a laboratory-based review of the epidemiology of legionellosis in Ontario over the past 3 decades, with a focus on changing rates of disease and species associated with legionellosis during that time period. METHODS: We analyzed cases that were submitted and tested positive for legionellosis from 1978 to 2006 using Poisson regression models incorporating temporal, spatial, and demographic covariates. Predictors of infection with culture-confirmed L. pneumophila serogroup 1 (LP1) were evaluated with logistic regression models. RESULTS: 1,401 cases of legionellosis tested positive from 1978 to 2006. As in other studies, we found a late summer to early autumn seasonality in disease occurrence with disease risk increasing with age and in males. In contrast to other studies, we found a decreasing trend in cases in the recent decade (IRR 0.93, 95% CI 0.91 to 0.95, P-value = 0.001); only 66% of culture-confirmed isolates were found to be LP1. CONCLUSION: Despite similarities with disease epidemiology in other regions, legionellosis appears to have declined in the past decade in Ontario, in contrast to trends observed in the United States and parts of Europe. Furthermore, a different range of Legionella species is responsible for illness, suggesting a distinctive legionellosis epidemiology in this North American region.


Travel-associated Legionnaires disease in Europe in 2007

Joseph CA, Yadav R, Ricketts KD; European Working Group for Legionella Infections.

Respiratory and Systemic Infections Department, Health Protection Agency Centre for Infections, London, United Kingdom.

Euro Surveill. 2009 May 7;14(18). pii: 19196

ABSTRACT: Nine hundred and forty six cases of travel-associated Legionnaires disease were reported to the European Surveillance Scheme for Travel Associated Legionnaires Disease (EWGLINET) with onset during 2007; 890 were confirmed and 56 were presumptive. Twenty eight cases died, giving a case fatality rate of 3.0%. 8.2% of cases were diagnosed by culture, an important increase from 5.2% in 2006. One hundred and twelve new clusters were identified; the largest involved nine cases. Sixteen of these clusters (14.3%) occurred in countries outside EWGLINET, and three involved cruise ships. Twenty nine of the new clusters (25.9%) would not have been detected without the EWGLINET scheme. A total of 151 investigations were conducted in Europe, 42 of which were conducted at re-offending sites (where additional cases had onset after a report was received to say that investigations and control measures had been satisfactorily conducted). The names of 13 accommodation sites were published on the European Working Group for Legionella Infections (EWGLI) website; 11 of these were situated in Turkey.


Seroepidemiological study after a long-distance industrial outbreak of legionnaires' disease

Wedege E, Bergdal T, Bolstad K, Caugant DA, Efskind J, Heier HE, Kanestrøm A, Strand BH, Aaberge IS.

Norwegian Institute of Public Health, Oslo, Norway.

Clin Vaccine Immunol. 2009 Apr;16(4):528-34.

ABSTRACT: Following a long-distance outbreak of Legionnaires' disease from an industrial air scrubber in Norway in 2005, a seroepidemiological study measuring levels of immunoglobulin G (IgG) and IgM antibodies to Legionella pneumophila was performed with a polyvalent enzyme-linked immunosorbent assay. One year after the outbreak, IgG levels in employees (n = 213) at the industrial plant harboring the scrubber and in blood donors (n = 398) from the outbreak county were low but significantly higher (P < or = 0.002) than those in blood donors (n = 406) from a nonexposed county. No differences in IgM levels among the three groups were found after adjustment for gender and age. Home addresses of the seroresponders in the exposed county clustered to the city of the outbreak, in contrast to the scattering of addresses of the seroresponding donors in the nonexposed county. Factory employees who operated at an open biological treatment plant had significantly higher IgG and IgM levels (P < or = 0.034) than those working >200 m away. Most of the healthy seroresponders among the factory employees worked near this exposure source. Immunoblotting showed that IgG and IgM antibodies in 82.1% of all seroresponders were directed to the lipopolysaccharide of the L. pneumophila serogroup 1 outbreak strain. In conclusion, 1 year after the long-distance industrial outbreak a small increase in IgG levels of the exposed population was observed. The open biological treatment plant within the industrial premises, however, constituted a short-distance exposure source of L. pneumophila for factory employees working nearby.


Factors influencing the case-fatality rate of Legionnaires' disease

Dominguez A, Alvarez J, Sabria M, Carmona G, Torner N, Oviedo M, Cayla J, Minguell S, Barrabeig I, Sala M, Godoy P, Camps N.

Department of Public Health, University of Barcelona, Barcelona, Spain.

Int J Tuberc Lung Dis. 2009 Mar;13(3):407-12.

ABSTRACT: SETTING: The extent of the public health problem posed by Legionnaires' disease (LD) is not always well- appreciated. OBJECTIVE: To determine the characteristics and factors associated with the case fatality rate (CFR) of LD in Catalonia, Spain. DESIGN: Confirmed cases of LD reported during 1993-2004 were studied. Age, sex, hospitalisation, the type of diagnostic confirmation test and the personal risk factors for LD of cases were collected. Comparative bivariate and multivariate analyses according to origin (community-acquired or nosocomial) and nature (sporadic or outbreaks) were performed. RESULTS: Of 1938 cases reported, 164 died (case-fatality rate [CFR] 8.5%). The CFR fell from 35% in 1993 to 5.6% in 2004, and was higher in sporadic than in outbreak-associated cases (10% vs. 4.7%) and in nosocomial than community-acquired cases (31.7% vs. 6.8%). In community-acquired cases, the CFR was associated with age >70 years (OR 3.42, 95%CI 2.02-5.79), cancer (OR 4.58, 95%CI 2.36-8.90) and diagnostic confirmation methods other than Legionella urinary antigen test. The CFR of nosocomial cases was not associated with any of these factors. CONCLUSIONS: The CFR of LD fell during the study period due to the incorporation of new diagnostic techniques and improved detection of outbreaks. 


Bacterial pneumonia in HIV-infected patients: use of the pneumonia severity index and impact of current management on incidence, aetiology and outcome

Curran A, Falcó V, Crespo M, Martinez X, Ribera E, Villar del Saz S, Imaz A, Coma E, Ferrer A, Pahissa A.

Infectious Diseases Department, Hospital Universitari Vall d'Hebron, Autonomous University of Barcelona, P1 Valld'Hebron, Barcelona, Spain.

HIV Med. 2008 Oct;9(8):609-15.

ABSTRACT: OBJECTIVES: Despite a recent decrease, bacterial pneumonia (BP) is still the most common admission diagnosis in HIV patients. We analyse BP incidence, characteristics and prevention measures. METHODS: Observational study of all patients hospitalized for BP in a tertiary hospital in Barcelona, Spain, from January 2000 to December 2005. Demographic and HIV-related data, BP risk factors, characteristics of BP and outcomes are analysed. RESULTS: One hundred and eighty-six BP episodes in 161 patients were included; patients were mainly male (73.7%) and intravenous drug users (73.7%). A decrease in BP incidence was seen during the study period, especially in vaccinated patients. The most commonly isolated microorganism was Streptococcus pneumoniae (31.7%), followed by Legionella pneumophila (5.9%). Legionella pneumophila was more likely in patients with undetectable viral load, higher CD4 cell counts or prior vaccination. Highly active antiretroviral therapy, cotrimoxazole prophylaxis and pneumococcal vaccination did not have a significant influence on bacteraemia rate, in-hospital complications or BP mortality. High Pneumonia Severity Index (PSI) predicted mortality accurately [relative risk 15.2, 95% confidence interval 3.2-71.7; P=0.001]. Mortality was 9.1%, but was significantly higher in patients with CD4 counts under 200 cells/microL (P=0.022). CONCLUSIONS: A decline in BP incidence was seen during the study period. Combining CD4 cell count and PSI score could become a good strategy in deciding which patients have to be hospitalized.


Increasing incidence of legionellosis in the United States, 1990-2005: changing epidemiologic trends

Neil K, Berkelman R.

Department of Epidemiology, Emory University, Atlanta, Georgia, USA.

Clin Infect Dis. 2008 Sep 1;47(5):591-9.

ABSTRACT: BACKGROUND: An abrupt increase in the incidence of legionellosis in the United States has been noted since 2003. Whether the recent increase is associated with shifting epidemiologic trends has not been well characterized. METHODS: We analyzed all cases of legionellosis reported to the Centers for Disease Control and Prevention through the National Notifiable Disease Surveillance System from 1990 through 2005. RESULTS: A total of 23,076 cases of legionellosis were reported to the Centers for Disease Control and Prevention from 1990 through 2005. The number of reported cases increased by 70% from 1310 cases in 2002 to 2223 cases in 2003, with a sustained increase to >2000 cases per year from 2003 through 2005. The eastern United States showed most of the increases in age-adjusted incidence rates after 2002, with the mean rate in the Middle Atlantic states during 2003-2005 exceeding that during 1990-2002 by 96%. During 2000-2005, legionellosis cases were most commonly reported in persons aged 45-64 years. Persons aged <65 years comprised 63% of total cases in 2000-2005. Age-adjusted incidence rates in males exceeded those in females for all age groups and years. Legionellosis incidence showed marked seasonality in eastern states, with most cases reported in the summer or fall. CONCLUSIONS: Reported legionellosis cases have increased substantially in recent years, particularly in the eastern United States and among middle-aged adults. Legionella infection should be considered in the differential diagnosis of any patient with pneumonia. Public health professionals should focus increased attention on detection and prevention of this important and increasing public health problem.


Travel-associated Legionnaires disease in Europe: 2006

Ricketts KD, Yadav R, Joseph CA; European Working Group for Legionella Infections.

Respiratory Diseases Department, Health Protection Agency Centre for Infections.

Euro Surveill. 2008 Jul 17;13(29). pii: 18930.

ABSTRACT: Twenty countries reported 921 cases of travel-associated Legionnaires' disease to EWGLINET (the European Surveillance Scheme for Travel-Associated Legionnaires' Disease) with onset during 2006; 875 confirmed and 46 presumptive. Thirty three cases died, giving a case fatality rate of 3.6%. Of the 124 new clusters detected in 2006, 43 would not have been identified without the EWGLINET scheme. A total of 146 investigations were conducted at cluster sites according to the standards of the EWGLINET investigation guidelines; 111 of these investigations were associated with the new clusters while 35 investigations were associated with re-offending sites (where additional cases had onset after a report was received to say that investigations and control measures had been satisfactorily conducted). The names of four accommodation sites were published on the EWGLI website. Overall, there has been an upwards trend in case numbers since the scheme was founded, which has implications for the work load of public health authorities across Europe and for the tour industry. Despite this increasing pressure on public health authorities, environmental investigations are being conducted in a timely manner.


Legionella pneumonia and HIV: case reports and review of the literature

Sandkovsky U, Sandkovsky G, Suh J, Smith B, Sharp V, Polsky B.

Department of Internal Medicine, St. Luke's-Roosevelt Hospital Center New York, New York 10025, USA.

AIDS Patient Care STDS. 2008 Jun;22(6):473-81.

ABSTRACT: Although Legionnaires' disease occurs more commonly in patients with some degree of immunosuppression (diabetes, chronic lung disease, end stage renal disease, cancer, etc.), it has been infrequently described in patients infected with human immunodeficiency virus (HIV) and AIDS. Some studies suggest that pneumonia caused by Legionella tends to present with more severe clinical features and complications in the HIV-infected population. The use of antibiotic prophylaxis or the association of severe pneumonia with other pathogens may account for under diagnosis of the disease. We diagnosed five cases of Legionella pneumonia in patients with HIV infection at our institution during a 1-year period. The cases seen ranged in severity, regardless of the CD4(+) counts of the patients. Based on our observations, it seems impossible to discern whether HIV infection is an additional risk factor for Legionnaires' disease. We describe those five cases and review the available literature.


Prevalence of anti-legionella antibodies among Italian hospital workers

Borella P, Bargellini A, Marchesi I, Rovesti S, Stancanelli G, Scaltriti S, Moro M, Montagna MT, Tatò D, Napoli C, Triassi M, Montegrosso S, Pennino F, Zotti CM, Ditommaso S, Giacomuzzi M.

Department of Public Health Sciences, University of Modena and Reggio Emilia, Italy.

J Hosp Infect. 2008 Jun;69(2):148-55.

ABSTRACT: This study evaluated the prevalence of anti-legionella antibodies in workers at hospitals with a long-term history of legionella contamination. The hospitals are located in Milan and Turin, northern Italy, and in Naples and Bari, southern Italy. Antibody prevalence and titres of healthcare workers, medical and dental students and blood donors were assessed. In total 28.5% of subjects were antibody positive, most frequently to L. pneumophila serogroups 7-14. Major differences were observed in seroprevalence and type of legionella antibody in persons from different geographic areas. Healthcare workers had a significantly higher frequency of antibodies compared with blood donors in Milan (35.4 vs 15.9%, P<0.001), whereas in Naples both groups exhibited high antibody frequency (48.8 vs 44.0%) and had a higher proportion of antibodies to legionella serogroups 1-6. Dental workers had a higher seroprevalence than office staff in Bari, but not in Turin, where daily disinfecting procedures had been adopted to avoid contamination of dental unit water. No association was found between the presence of antibodies and the presence of risk factors for legionellosis, nor with the occurrence of pneumonia and/or flu-like symptoms. In conclusion, the presence of legionella antibodies may be associated with occupational exposure in the hospital environment, but there was no evidence of any association with disease.


Legionella pneumonia in cancer patients

Jacobson KL, Miceli MH, Tarrand JJ, Kontoyiannis DP.

Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.

Medicine (Baltimore). 2008 May;87(3):152-9.

ABSTRACT: Legionella is an important cause of nosocomial and community-acquired pneumonia in both immunocompetent and immunosuppressed patients worldwide; however, the clinical course and optimal antibiotic therapy of Legionella pneumonia (LP) in patients with cancer is uncertain. We studied retrospectively the risk factors, clinical manifestations, and outcome of 49 cancer patients with a positive Legionella culture or direct fluorescent antibody (DFA) over a 13-year period (1991-2003). The majority of patients (82%) had an underlying hematologic malignancy, and 37% were bone marrow transplant recipients; 80% of the patients had active malignancy. Lymphopenia (47%), use of systemic corticosteroids (41%), and chemotherapy (63%) were the most common underlying conditions. The laboratory diagnosis was established by positive Legionella culture (n = 8, 16%), DFA (n = 29, 59%), or both (n = 12, 25%). In 4 patients (8%), a positive DFA was deemed to represent false-positive results. There was no temporal or geographic clustering of cases. The majority of the cases had multilobar (61%) or bilateral (55%) pulmonary involvement.The mean time to response to therapy was 8 days; 18 patients (37%) developed complications requiring prolonged duration of treatment (mean, 25 d). The case-fatality rate was 31%. Two patients had relapse of LP despite appropriate therapy. Improved outcome, especially in those with severe pneumonia, seemed to correlate with the use of a combination of antibiotics. LP is an uncommon infection in our patient population but is associated with significant morbidity and mortality. Treatment of LP in cancer patients may require a prolonged course with a regimen that includes a newer macrolide or quinolone.


Legionella colonization of the respiratory tract in patients without nosocomial exposure

Ditommaso S, Giacomuzzi M, Gentile M, Ruggenini Moiraghi A, Arione R, Baldi S, Solidoro P, Ceccarelli A, Zotti CM.

Dipartimento di Sanità Pubblica e di Microbiologia (S.D., M. Giacomuzzi, M. Gentile, A.R.M., C.M.Z.) and the Dipartimento di Scienze Cliniche e Biologiche (A.C.), Università di Torino, and the Direzione Sanitaria (R.A.) and the Divisione di Pneumologia (S.B., P.S.), Azienda Sanitaria Ospedaliera San Giovanni Battista, Torino, Italy.

Infect Control Hosp Epidemiol. 2008 May;29(5):470-471.



Legionella spp. and Legionnaires' disease

Diederen BM.

Regional Laboratory of Public Health Haarlem, Boerhaavelaan 26, 2035 RC Haarlem, The Netherlands.

J Infect. 2008 Jan;56(1):1-12.

ABSTRACT: Infection with Legionella spp. is an important cause of community- and hospital-acquired pneumonia, occurring both sporadically and in outbreaks. Infection with Legionella spp. ranks among the three most common causes of severe pneumonia in the community setting, and is isolated in 1-40% of cases of hospital-acquired pneumonia. There are no clinical features unique to Legionnaires' disease. Macrolides and fluoroquinolones are the most widely used drugs in treatment. The availability of a good diagnostic repertoire, suitable for accurately diagnosing LD, constitutes the basis for the early recognition and treatment of the individual patient as well as for effective measures for prevention and control. This review summarizes the available information regarding the microbiology, clinical presentation, diagnosis and treatment of LD, with an emphasis on the laboratory diagnosis of infection with Legionella spp.


Identification of Legionella spp. by 19 European reference laboratories: results of the European Working Group for Legionella Infections External Quality Assessment Scheme using DNA sequencing of the macrophage infectivity potentiator gene and dedicated online tools

Fry NK, Afshar B, Bellamy W, Underwood AP, Ratcliff RM, Harrison TG; European Working Group for Legionella Infections.

Respiratory and Systemic Infection Laboratory, Health Protection Agency Centre for Infections, London, UK.

Clin Microbiol Infect. 2007 Nov;13(11):1119-24.

ABSTRACT: Identification of Legionella spp. can be achieved by DNA sequencing of the macrophage infectivity potentiator (mip) gene. The External Quality Assurance (EQA) scheme described in this report is the first to assess the proficiency of laboratories using this methodology. The results obtained from two EQA distributions sent to European reference laboratories involved in Legionella outbreak control and environmental monitoring are presented. Each distribution contained a panel of ten coded Legionella strains. All strains were from clinical and environmental sources and were considered to be wild-type strains. Participants used dedicated online tools to compare sequence text files against a database of known Legionella spp. The majority of centres (seven of ten, and 11 of 12) correctly identified all strains tested, in the first and second distributions, respectively. Typically, sequence similarity values of 98-100% were obtained when the test strains were compared with sequences contained in the database. In all but one case, lower values indicated a poor quality sequence. The exception was associated with the identification of a putative new species in the first panel. Genotypic identification of Legionella can be achieved by the use of standard protocols, dedicated identification libraries, and online tools. EQA schemes provide an independent measure of performance, and it is recommended that laboratories performing these techniques participate in such schemes, thereby allowing optimisation of and improvements in their performance.


Active surveillance of legionnaires disease during a prospective observational study of community- and hospital-acquired pneumonia

Leoni E, Sacchetti R, Aporti M, Lazzari C, Donati M, Zanetti F, De Luca G, Finzi GF, Legnani PP.

Department of Medicine and Public Health, Division of Hygiene, University of Bologna, Via S. Giacomo 12, 40126 Bologna, Italy.

Infect Control Hosp Epidemiol. 2007 Sep;28(9):1085-8.

ABSTRACT: A prospective surveillance study of legionnaires disease and an environmental survey of Legionella species were performed simultaneously in a general hospital. During a period of 3 years, 705 patients with pneumonia were screened with a Legionella urinary antigen test, and pneumonia was confirmed by culture and serological tests. Twelve cases of legionnaires disease were identified, none of which were hospital acquired, despite the fact that 60% of hospital water samples were contaminated with Legionella pneumophila at a concentration of more than 10(3) colony-forming units/L. The probable source of infection was identified for only 2 community-acquired cases. The results show that environmental contamination alone is not able to predict the risk of legionnaires disease. If no cases are present, monitoring of hospital water systems is of little significance; clinical surveillance is much more important.


The influence of age and gender on the population-based incidence of community-acquired pneumonia caused by different microbial pathogens in a population-based prospective cohort study

Gutierrez F, Masia M, Mirete C, Soldan B, Carlos Rodriguez J, Padilla S, Hernandez I, Royo G, Martin-Hidalgo A.

Infectious Diseases Unit, Internal Medicine Department, Hospital General Universitario de Elche, Cami de la Almazara S/N, 03203 Elche, Alicante, Spain.

J Infect. 2006 Sep;53(3):166-74.

ABSTRACT: OBJECTIVES: To determine the population-based incidence of community-acquired pneumonia (CAP) in adults and to assess the relative importance of age and gender on the incidence of infections caused by different microbial pathogens. METHODS: A two-year prospective study in a well-defined geographic area of the Spanish Mediterranean coast. RESULTS: The overall incidence rate of CAP was 12 cases (95% CI 11.25-13.45) per 10,000 person-years. Incidence rates increased by age (p<0.0001) and they were higher in males (16 versus 9 cases per 10,000 person-years; p<0.0001). The rate was especially high among males aged >/=75years (87 cases per 10,000 person-years). The incidence of pneumococcal pneumonia increased significantly with ageing and it was particularly high among people aged >/=75 years (10 cases per 10,000 person-years). Very elderly people had also a 15-fold higher incidence of CAP associated with influenza virus and a 5-fold higher incidence of infections by Chlamydophila spp., than young adults. The incidence of infections with Legionella pneumophila also increased with age and it was 10 times higher in males. In contrast, the incidence of pneumonia caused by Mycoplasma pneumoniae was unrelated to age and gender. CONCLUSIONS: Age and gender have a strong influence on the overall incidence of CAP and on the incidence of pneumonia caused by the main microbial pathogens, including not only Streptococcus pneumoniae, but also influenza virus, Chlamydophila spp. and L. pneumophila. Ageing is associated with a higher risk of acquiring pneumonia by S. pneumoniae, influenza virus and Chlamydophila spp., whereas male gender increases greatly the incidence of L. pneumophila and Chlamydophila spp.


Active clinical surveillance for detection of Legionnaires' disease: implications for health care structures

Marchesi I, Bargellini A, Concetti S, Marchegiano P, Cauteruccio L, Casolari C, Borella P.

Dipartimento di Scienze di Sanità Pubblica, Università degli Studi di Modena e Reggio Emilia.

Ann Ig. 2007 Jul-Aug;19(4):295-302.

ABSTRACT: In an university hospital of about 900 beds, a clinical surveillance was activated to detect cases of Legionnaires' disease in patients affected by community and/or nosocomial-acquired pneumonia. In the hospital Legionella spp was detected in the hot water distribution system and various disinfecting and control procedures were adopted to reduce contamination. Contemporary, the clinical surveillance began with the systematic detection of Legionella urinary antigen among recovered pneumonia, seroconversion as confirmation test and the collection of respiratory secretions or other biological materials to isolate the microorganism in patients positive to the urinary antigen. From September 2003 to May 2005, 486 pneumonia were followed, 98 of which considered of nosocomial origin. In total, 15 cases of community-acquired Legionnaires' disease were detected by the urinary test, whereas no cases of nosocomial origin were found. The characteristics of the detected cases are described in comparison with the other pneumonia and the surveillance cost was evaluated. The systematic clinical surveillance for Legionella infections is feasible with limit costs, allows to detect community-acquired cases otherwise unknown and to ascertain the absence/presence of nosocomial-acquired pneumonia, irrespective of the environment contamination.


High prevalence of antibodies to Legionella spp. in Danish blood donors. A study in areas with high and average incidence of Legionnaires' disease

Rudbeck M, Mølbak K, Uldum S.

Department of Bacteriology, Mycology, and Parasitology, Statens Serum Institut, Denmark.

Epidemiol Infect. 2007 May 3:1-6.

ABSTRACT: The incidence of Legionnaires' disease has an uneven geographical distribution in Denmark, ranging from 3 to 70 notified cases per million inhabitants per year in different towns. We investigated the prevalence of antibodies to Legionella in the one town with a consistently high incidence (Randers, Aarhus County) and compared it with that of an area of average incidence (Vejle, Vejle County). Blood samples were collected from healthy blood donors in Randers (n=308) and in Vejle (n=400), and analysed for antibodies to Legionella by indirect immunofluorescence antibody test with L. pneumophila, L. micdadei, and L. bozemanii as antigens. Overall 22•9% of the donors had antibody titres of  1:128; indicating that antibodies to Legionella are common in healthy individuals, and reflecting that the bacteria may be widely distributed in the environment. Surprisingly, the study did not reveal a higher prevalence in the hyperendemic area. Thus, the high incidence of notified cases in this particular town may not be attributed to an overall increased exposure of the general population.


Incidence of legionellosis in hospitals contaminated by Legionella pneumophila other than serogroup 1

Ditommaso S, Giacomuzzi M, Biasin C, Gentile M, Maggiorotto G, Ruggenini Moiraghi A, Zotti CM; Legionellosis Collaborating Group.

Dipartimento di Sanità Pubblica e di Microbiologia, Università degli Studi di Torino, Turin, Italy.

Infect Control Hosp Epidemiol. 2007 Apr;28(4):509-11. 



Legionnaires' disease and gardening

den Boer JW, Yzerman EP, Jansen R, Bruin JP, Verhoef LP, Neve G, van der Zwaluw K.

Municipal Health Service, Kennemerland, Haarlem, the Netherlands.

Clin Microbiol Infect. 2007 Jan;13(1):88-91. 

ABSTRACT: Legionella longbeachae was cultured from the sputum of a patient suffering from Legionnaires' disease. Source identification efforts included analysis of samples of potting soil from the patient's garden, and a genotypically indistinguishable strain of L. longbeachae was cultured from this material. Following examination of a national collection of Legionella isolates, two more patients with indistinguishable genotypes were identified. One of these patients had visited a garden centre in the same municipality in which the index patient had acquired his potting soil. The study demonstrated the value of systematic collection of identification data and patient isolates over a prolonged period.


Streptococcus pneumoniae and Legionella pneumophila pneumonia in HIV-infected patients

Pedro-Botet ML, Sopena N, García-Cruz A, Mateu L, García-Núñez M, Rey-Joly C, Sabrià M.

Infectious Diseases Unit, Universitat Autònoma de Barcelona, Spain.

Scand J Infect Dis. 2007;39(2):122-8.

ABSTRACT: We compared the epidemiological data, clinical features and mortality of community-acquired pneumonia (CAP) by Streptococcus pneumoniae and Legionella in HIV-infected patients and determined discriminative features. An observational, comparative study was performed (January 1994 to December 2004) in 15 HIV patients with CAP by Legionella and 46 by S. pneumoniae. No significant differences were observed in delay until initiation of appropriate antibiotic therapy. Smoking, cancer and chemotherapy were more frequent in patients with Legionella pneumonia (p=0.03, p=0.00009 and p=0.01). Patients with Legionella pneumonia had a higher mean CD4 count (p=0.04), undetectable viral load (p=0.01) and received highly active antiretroviral therapy more frequently (p=0.004). AIDS was more frequent in patients with S. pneumoniae pneumonia (p=0.03). Legionella pneumonia was more severe (p=0.007). Extrarespiratory symptoms, hyponatraemia and increased creatine phosphokinase were more frequent in Legionella pneumonia (p=0.02, p=0.002 and p=0.006). Respiratory failure, need for ventilation and bilateral chest X-ray involvement were of note in the Legionella group (p=0.003, p=0.002 and p=0.002). Mortality tended to be higher in the Legionella group (6.7 vs 2.2%). In conclusion, CAP by Legionella has a higher morbimortality than CAP by S. pneumoniae in HIV-infected patients. Detailed analysis of CAP presentation features allows suspicion of Legionnaires' disease in this subset.


Legionella prevalence in hot spring recreation areas of Taiwan

Hsu BM, Chen CH, Wan MT, Cheng HW

Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC.

Water Res. 2006 Oct;40(17):3267-73.

ABSTRACT: Legionella is a bacterium ubiquitous to aquatic environments. Within the genus a few species are recognized as opportunistic potential human pathogens, especially the species Legionella pneumophila, which causes pneumonia legionellosis. Outbreaks of legionellosis are frequently reported by hotel guests and hospital patients, and are spread through inhaled aerosols of contaminated institutional water systems. Contaminations in hot tubs, spas and public baths are also possible. As a result, in this study, we investigated the distribution of Legionella at seven hot spring recreational areas throughout Taiwan. We gathered data on factors potentially associated with the pathogen's distribution, including environment, facility operation, and physical and microbiological water quality parameters. Spring water was collected from 91 sites and Legionella was detected in 21 (23%). The most frequently detected was L. pneumophila, followed by uncultured Legionella species, Legionella-like amoebal pathogen. Five species, L. bozemanii, L. dumoffi, L. feelei, L. lyticum and L. oakridgenesis, were all detected once. Legionella species were found in water temperatures ranging from 22 to 50 degrees C. Optimal pH appeared to be between 5.0 and 9.0. The prevalence of Legionella also coincided with the prevalence of indicator microorganisms. Legionella detection was not proportional to the frequency of cleaning. Results of this survey confirm the ubiquity of Legionella in Taiwan spring recreation areas. L. pneumophila, the organism responsible for the majority of legionellosis outbreaks, should be considered a potential public health threat in spa areas of Taiwan.


Problem pathogens: paediatric legionellosis--implications for improved diagnosis

Greenberg D, Chiou CC, Famigilleti R, Lee TC, Yu VL.

Soroka University Medical Center, Beer-Sheeva, Israel.

Lancet Infect Dis. 2006 Aug;6(8):529-35.

ABSTRACT: Legionnaires' disease is an established and frequent cause of pneumonia in adults but is thought to be a rare cause in children. We reviewed the medical literature for cases of Legionnaires' disease in children and analysed the epidemiology, clinical characteristics, and treatment. 76 cases of legionella infection in children were identified. In 56%, diagnosis was made with culture methodology. 46% were community-acquired infections. 51.5% were under 2 years of age. 78% of the patients had an underlying condition such as malignancy. Fever, cough, and tachypnoea were the most common symptoms. The overall mortality rate was 33% and was higher in immunosuppressed children and in children younger than the age of 1 year. Patients who were treated empirically with anti-legionella therapy had a notably lower mortality rate compared with patients on inappropriate therapy (23%vs 70%). In 88% of hospital-acquired cases, an environmental link to potable water colonised with legionella was identified. We found no clinical features unique to Legionnaires' disease in children that would allow differentiation from pneumonia due to other respiratory pathogens. Awareness of legionella as a potential cause of paediatric pneumonia is particularly important because infection can be severe and life threatening and antimicrobial therapy often used for empirical therapy in children is not effective against legionella. In any case of pneumonia unresponsive to antibiotics, Legionnaires' disease should be considered and specific diagnostic tests to verify this diagnosis should be done. As legionella diagnostic tests become more widely applied, we predict that legionellosis may appear as an emerging infectious disease in children.


Legionella spp. in hospital dental facilities.

Tanzi ML, Capobianco E, Affanni P, Pizzi S, Vitali P, Veronesi L.

Public Health Department, University of Parma, Italy.

J Hosp Infect. 2006 Jun;63(2):232-4.



Estimation of minimum infection rates with Legionella pneumophila in an exposed population

Boshuizen HC, Nagelkerke NJ, DEN Boer JW, DE Melker H, Schellekens JF, Peeters MF, VAN Vliet H, Conyn-VAN Spaendonck MA.

National Institute for Public Health and the Environment, Bilthoven, The Netherlands.

Epidemiol Infect. 2006 Jun;134(3):579-84.

ABSTRACT: The distribution of antibody levels to Legionella (L.) pneumophila (serotypes 1-7) was compared between subjects who worked near the source of a large outbreak of Legionnaires' disease (n=668) and a population sample of comparable age (n=480). In a previous analysis of these data, it was estimated that 80% of those working near the source were infected with L. pneumophila. However, the estimation procedure implicitly assumes that the probability of infection does not depend on the antibody level of a person before exposure. This is questionable, as antibodies could protect against infection. We have now estimated the minimum value consistent with the data on the number of infected persons. We observed that a minimum of 40% [95% confidence interval (CI) 32-48] of those working near the source and 13% (95% CI 8-18) of those working further away were infected with L. pneumophila. Implications of these findings for design options in future research are discussed.


Clinical-environmental surveillance of legionellosis: an experience in southern Italy

Montagna MT, Napoli C, Tato D, Spilotros G, Barbuti G, Barbuti S.

Department of Internal Medicine and Public Health - Hygiene Section, University of Bari, P. zza G. Cesare, 1170124, Bari, Italy.

Eur J Epidemiol. 2006;21(4):325-31.

In Italy, although the number of cases of legionellosis notified to the health authorities has significantly increased in recent years, the incidence is still believed to be underestimated. To verify the true frequency and identify the sources of infection, an active clinical-environmental surveillance program was instituted in three hospital facilities in Southern Italy. Between January 2001 and March 2005, a total of 1000 patients admitted to the three hospitals with a diagnosis of pneumonia were enrolled. The urinary antigen and anti-Legionella antibody titre were assayed in each subject, and direct searches for the microorganism were made in biological specimens. Legionellosis was found to be present in 5.9% of the patients. For each of the cases of legionellosis, microbiological surveys were made of the water supply in the public and/or private facilities involved. Overall, 197 water samples of hospital origin and 218 of community origin were analysed: Legionella spp was isolated in 44.2 and 36.7% of the cases, respectively. Comparison of our data with those of the routine surveillance system for the same area (only 7 cases during the period 1997-2000), showed that the frequency of legionellosis is grossly underestimated in Southern Italy. It is therefore necessary to set up more rigorous controls in both hospital and community facilities, so that timely preventive measures can be taken to avoid any further spread of the disease.


Colonization of a water system by Legionella organisms and nosocomial legionellosis: a 5-year report from a large Italian hospital

Ditommaso S, Biasin C, Giacomuzzi M, Zotti CM, Arione R, Guglielmi E, Barbaro S, Di Leo A, Serra R, Marchiaro G, Ruggenini Moiraghi A.

Dipartimento di Sanità Pubblica e di Microbiologia, Università degli Studi di Torino (S.D., C.B., M.G., C.M.Z., A.D., A.R.M.), and Direzione Sanitaria (R.A., E.G., S.B.) and Laboratorio di Microbiologia (R.S., G.M.), Azienda Sanitaria Ospedaliera S. Giovanni Battista, Turin, Italy.

Infect Control Hosp Epidemiol. 2006 May;27(5):532-5.



Prospective 3-year surveillance for nosocomial and environmental Legionella pneumophila: implications for infection control

Boccia S, Laurenti P, Borella P, Moscato U, Capalbo G, Cambieri A, Amore R, Quaranta G, Boninti F, Orsini M, Branca G, Fadda G, Romano-Spica V, Ricciardi G.

Institute of Hygiene, Catholic University Medical School, Rome, Italy.

Infect Control Hosp Epidemiol. 2006 May;27(5):459-65.

OBJECTIVES: To perform a 3-year, prospective surveillance program for legionnaires disease (LD) in a large university hospital in Rome, and to assess the usefulness of the hospital water monitoring program in predicting the risk of nosocomial LD. METHODS: Samples from patients with new cases of nosocomial pneumonia were sent for legionella laboratory investigations. Meanwhile, water samples for bacteriological analysis were collected every 6 months from high- and medium-risk hospital wards (10 in total). Legionella pneumophila isolates collected were serotyped and analyzed by pulsed-field gel electrophoresis. RESULTS: From June 2001 through May 2004, the pneumonia surveillance identified one case of nosocomial LD among 43 cases of nosocomial pneumonia (2.3%). Environmental investigations detected L. pneumophila in 12 (18.7%) of the 64 water samples, of which 50% belonged to serogroup 1. The L. pneumophila count and the percentage of positive locations never exceeded 10(2) colony-forming units/L and 20%, respectively, except when the LD nosocomial case occurred (positive water samples, 40%; L. pneumophila count, <10(2) colony-forming units/L). Genotyping showed 3 prevalent clones of L. pneumophila in the water distribution network, of which one persisted over the 3 years. One clone contained 3 different L. pneumophila serogroups (2, 4, and 6). CONCLUSIONS: The low incidence of nosocomial cases of LD appears to be associated with a low percentage (<20%) of positive water samples per semester and with a low contamination level (<10(2) colony-forming units/L). An infection control system for nosocomial LD should, therefore, be based on both environmental and clinical surveillance, together with the appropriate maintenance of the hospital water distribution system.


Pontiac fever: an operational definition for epidemiological studies

Tossa P, Deloge-Abarkan M, Zmirou-Navier D, Hartemann P, Mathieu L.

Departement Environnement et Sante Publique, INSERM ERI 11, Henri Poincare University, BP 184-54 505 Vandoeuvre les Nancy, France.

BMC Public Health. 2006 Apr 28;6:112.

BACKGROUND: Pontiac fever is usually described in epidemic settings. Detection of Pontiac fever is a marker of an environmental contamination by Legionella and should thereby call for prevention measures in order to prevent outbreak of Legionnaire's disease. The objective of this study is to propose an operational definition of Pontiac fever that is amenable to epidemiological surveillance and investigation in a non epidemic setting. METHODS: A population of 560 elderly subjects residing in 25 nursing homes was followed during 4 months in order to assess the daily incidence of symptoms associated, in the literature, with Pontiac fever. The water and aerosol of one to 8 showers by nursing home were characterized combining conventional bacterial culture of Legionella and the Fluorescence In Situ Hybridization (FISH) technique that used oligonucleotides probes specific for Legionellaceae. A definition of Pontiac fever was devised based on clinical symptoms described in epidemic investigations and on their timing after the exposure event. The association between incidence of Pontiac fever and shower contamination levels was evaluated to test the relevance of this definition. RESULTS: The proposed definition of Pontiac fever associated the following criteria: occurrence of at least one symptom among headache, myalgia, fever and shivers, possibly associated with other 'minor' symptoms, within three days after a shower contaminated by Legionella, during a maximum of 8 days (minimum 2 days). 23 such cases occurred during the study (incidence rate: 0.125 cases per person-year [95% CI: 0.122-0.127]). A concentration of Legionella in water equal to or greater than 10(4).L(-1) (FISH method) was associated with a significant increase of incidence of Pontiac fever (p = 0.04). CONCLUSION: Once validated in other settings, the proposed definition of Pontiac fever might be used to develop epidemiological surveillance and help draw attention on sources of Legionella.


Prevalence study of Legionella spp. contamination in ferries and cruise ships

Azara A, Piana A, Sotgiu G, Dettori M, Deriu MG, Masia MD, Are BM, Muresu E.

Hygiene and Preventive Medicine Institute, University of Sassari, Sassari, Italy.

BMC Public Health. 2006 Apr 18;6:100.

BACKGROUND: In the last years, international traffic volume has significantly increased, raising the risk for acquisition of infectious diseases. Among travel-associated infections, increased incidence of legionellosis has been reported among travellers. Aim of our study was: to describe the frequency and severity of Legionella spp. contamination in ferries and cruise ships; to compare the levels of contamination with those indicated by the Italian ministerial guidelines for control and prevention of legionellosis, in order to assess health risks and to adopt control measures. METHOD: A prevalence study was carried out on 9 ships docked at the seaports of northern Sardinia in 2004. Water samples were collected from critical sites: passenger cabins, crew cabins, kitchens, coffee bars, rooms of the central air conditioning system. It was performed a qualitative and quantitative identification of Legionella spp. and a chemical, physical and bacteriological analysis of water samples. RESULTS: Forty-two percent (38/90) water samples were contaminated by Legionella spp.. Positive samples were mainly drawn from showers (24/44), washbasins (10/22). L. pneumophila was isolated in 42/44 samples (95.5%), followed by L. micdadei (4.5%). Strains were identified as L. pneumophila serogroup 6 (45.2%; 19 samples), 2-14 (42.9%), 5 (7.1%) and 3 (4.8%). Legionella spp. load was high; 77.8% of the water samples contained > 10(4) CFU/L. Low residual free chlorine concentration (0-0.2 mg/L) was associated to a contamination of the 50% of the water samples. CONCLUSION: Legionella is an ubiquitous bacterium that could create problems for public health. We identified Legionella spp. in 6/7 ferries. Microbial load was predominantly high (> 10(4) CFU/L or ranging from 10(3) to 10(4) CFU/L). It is matter of concern when passengers are subjects at risk because of Legionella spp. is an opportunist that can survive in freshwater systems; high bacterial load might be an important variable related to disease's occurrence. High level of contamination required disinfecting measures, but does not lead to a definitive solution to the problem. Therefore, it is important to identify a person responsible for health safety in order to control the risk from exposure and to apply preventive measures, according to European and Italian guidelines.


A study of Legionella pneumophilia in Tianjin, China

Liu HL, Lam LT, Hou CC, Xu Y, Chen XM.

Department of Occupation Health and Environmental Health, Tongji Medical College, Huazhong University of Science and Technology, China.

Int J Environ Health Res. 2006 Feb;16(1):15-20.

ABSTRACT: Legionella is a bacterium identified as the causative agent of Legionnaires' disease commonly found in water and soil in natural environments and human habitats. While most studies are focused on cooling tower water as the source of infection, few studies have compared Legionella from cooling-tower water and water in man-made environments. This cross-sectional study with a randomized cluster sampling design aims to provide information on Legionella found in cooling-tower water and water in man-made environments. Legionella was identified using a dual analytical approach: the serological and the 16SrRNA semi-nest PCR methods. Nine different types of Legionella were identified with the Lp7 type detected in China for the first time. Results indicated slight but insignificantly increased odds (OR = 1.64, 95%CI = 0.54-4.98) of Legionella detection in cooling tower water as compared to water obtained from fountains and parks, suggesting that the mechanism of exposure plays an important role in the causal pathway of outbreaks of Legionnaires' disease.


Ameba-associated microorganisms and diagnosis of nosocomial pneumonia

Berger P, Papazian L, Drancourt M, La Scola B, Auffray JP, Raoult D.

Centre Hospitalier Universitaire La Timone, Marseille, France.

Emerg Infect Dis. 2006 Feb;12(2):248-55.

ABSTRACT: To elucidate the role of ameba-associated microorganisms (AAMs) as etiologic agents of pneumonia, we screened for Legionella spp., Parachlamydia acanthamoeba, Afipia sp., Bosea spp., Bradyrhizobium spp., Mesorhizobium amorphae, Rasbo bacterium, Azorhizobium caulinodans, Acanthamoeba polyphaga mimivirus, and conventional microorganisms in 210 pneumonia patients in intensive-care units by using culture, polymerase chain reaction, and serologic testing. These resulted in 59 diagnoses in 40 patients. AAMs and non-AAMs were implicated in 10.5% of the patients. The infectious agents were identified in 15 patients: Acanthamoeba polyphaga mimivirus, 8; Legionella pneumophila, 3; L. anisa, 1; Parachlamydia sp., 1; Bosea massiliensis, L. worsleiensis, L. quinlivanii, and L. rubrilucens, 1; and M. amorphae and R. bacterium, 1. A. polyphaga mimivirus was the fourth most common etiologic agent, with a higher seroprevalence than noted in healthy controls. This finding suggested its clinical relevance. Therefore, AAM might cause nosocomial pneumonia and should be suspected when conventional microbiologic results are negative.


Seroprevalence of Legionella pneumophila in pneumonia patients in four major hospitals in Trinidad and Tobago

Nagalingam NA, Adesiyun AA, Swanston WH, Bartholomew M.

School of Medicine, Faculty of Medical Sciences, The University of the West Indies, St Augustine, Trinidad and Tobago.

West Indian Med J. 2005 Dec;54(6):375-8.

Trinidad and Tobago is an island-state in the Caribbean with a size of 5,128 square kilometers and a population of 1.3 million. Pneumonia is a leading cause of death in Trinidad. This project determined the frequency of Legionella pneumophila in patients with pneumonia, investigated the relationship between pneumonia and selected risk factors. Serum and demographic data were collected from 123 patients, diagnosed with pneumonia. Sera were tested for L pneumophila Ig G/M/A and IgM. All analyses were done using the SPSS statistical package. Of a total of 123 serum samples tested, 39 (31.7) were positive for L pneumophila IgM/G/A while 2 (1.6%) were positive for IgM only. Hospitals, gender and ethnicity did not significantly (p > 0.05; chi-squared) affect the seroprevalence of L pneumophila. Overall, the prevalence of L pneumophila assayed was not significantly (p > 0.05, chi-squared) affected by co-morbidities.



Pedro-Botet ML, Sabria M.

Infectious Diseases Unit, Hospital Universitari Germans Trias I Pujol, Universitat Autonoma de Barcelona, Badalona, Barcelona, Spain.

Semin Respir Crit Care Med. 2005 Dec;26(6):625-34.

ABSTRACT: Community-acquired Legionnaires‘ disease (CALD) has dramatically increased in the Legionella urinary antigen (LUA) era. However, its incidence in each country depends on the specific techniques used for the diagnosis of LD and the mandatory reporting of cases to the local health surveillance system. Moreover, the most recent studies have demonstrated that no clinical data are discriminative enough for the diagnosis of LD. Clinical differences have been observed in sporadic and outbreak-reported cases demonstrating that the earlier the diagnosis of Legionella infection, the more nonspecific the clinical appearance. Fluoroquinolones are the most efficacious drugs against Legionella. The combination of these drugs with azithromycin seems to be promising in the treatment of patients with severe LD. Although outbreaks of LD will continue, the most important objective of the public health authorities should be to reduce their number and size.


Legionella infection

Murray S.

CMAJ. 2005 Nov 22;173(11):1322.



It's Not the Heat, It's the Humidity: Wet Weather Increases Legionellosis Risk in the Greater Philadelphia Metropolitan Area

Fisman DN, Lim S, Wellenius GA, Johnson C, Britz P, Gaskins M, Maher J, Mittleman MA, Victor Spain C, Haas CN, Newbern C.

School of Public Health, Drexel University, Philadelphia, Pennsylvania, USA. Present affiliation: Center for Health and Wellbeing, Princeton University, Princeton, New Jersey, USA.

J Infect Dis. 2005 Dec 15;192(12):2066-73.

ABSTRACT: Background. Legionella species are abundant in the environment and are increasingly recognized as a cause of severe pneumonia. Increases in cases of community-acquired legionellosis in the greater Philadelphia metropolitan area (GPMA) led to concern that changing environmental factors could influence occurrence of disease.Methods. We evaluated the association between weather patterns and occurrence of legionellosis in the GPMA, using both traditional Poisson regression analysis and a case-crossover study approach. The latter approach controls for seasonal factors that could confound the relationship between weather and occurrence of disease and permits the identification of acute weather patterns associated with disease.Results. A total of 240 cases of legionellosis were reported between 1995 and 2003. Cases occurred with striking summertime seasonality. Occurrence of cases was associated with monthly average temperature (incidence rate ratio [IRR] per degree Celsius, 1.07 [95% confidence interval {CI}, 1.05-1.09]) and relative humidity (IRR per 1% increase in relative humidity, 1.09 [95% CI, 1.06-1.12]) by Poisson regression analysis. However, case-crossover analysis identified an acute association with precipitation (odds ratio [OR], 2.48 [95% CI, 1.30-3.12]) and increased humidity (OR per 1% increase in relative humidity, 1.08 [95% CI, 1.05-1.11]) 6-10 days before occurrence of cases. A significant dose-response relationship for occurrence of cases was seen with both precipitation and increased humidity.Conclusions. Although, in the GPMA, legionellosis occurred predominantly during summertime, the acute occurrence of disease is best predicted by wet, humid weather. This finding is consistent with the current understanding of the ecological profile of this pathogen and supports the contention that sporadic legionellosis occurs through contamination of water sources.


Legionella pneumonia: many cases of Legionnaire disease go unreported or unrecognized

Todd B.

New York Presbyterian Hospital, Columbia University Medical Center, in New York City, USA.

Am J Nurs. 2005 Nov;105(11):35-6, 38.



Legionella pneumophila infection in the Taiwan area

Su HP, Tseng LR, Chou CY, Chung TC, Pan TM.

Center for Disease Control, Department of Health, Taiwan, ROC.

J Infect Chemother. 2005 Oct;11(5):244-9.

ABSTRACT: The aim of this study was to explore the epidemiological distribution of legionellosis among pneumonia patients in Taiwan. From January 2001 to December 2003, specimens (i.e., sputum, urine, and serum) from a total of 5097 patients with pneumonia or pneumonia-like disease registered at hospitals in the Taiwan area were analyzed for possible Legionella infection. Following the guideline issued by the Centers for Disease Control and Prevention (CDC) in the United States, a total of 237 pneumonia patients were diagnosed with legionellosis, with an incidence rate among pneumonia patients in this area of 4.7% (237/5097). The paired-serum antibody test was found to be the most effective detection method, followed by urine-antigen detection and the sputum culture method. Analysis of distribution showed that: (1) male and female occurrence rates were 70.9% (168/237) and 29.1% (69/237), respectively; (2) occurrence rates in different age groups, i.e., those aged between 61 and 80 years, those aged between 41 and 60, and those aged between 21 and 40 were 50.2% (119/237), 26.2% (62/237), and 12.2% (29/237), respectively; (3) autumn was the peak season for infection, followed by winter, summer, and spring, sequentially. This is the first study in Taiwan to have followed the three-method guideline issued by the CDC and it is the second report in Taiwan involving the investigation of a large series of pneumonia patients for legionellosis detection.


Legionella waltersii--a novel cause of pneumonia?

Konig C, Hebestreit H, Valenza G, Abele-Horn M, Speer CP.

University Children's Hospital, Wurzburg, Germany.

Acta Paediatr. 2005 Oct; 94(10):1505-7.

ABSTRACT: A 5-y-old girl was admitted to our hospital with fever, cough, respiratory distress and rapidly increasing oxygen requirements. A chest radiograph showed bilateral central infiltrates. PCR was performed with pharyngeal washings and revealed Legionella DNA, while no genetic materials of other pathogens such as respiratory viruses, Mycoplasma and Chlamydia were detected. The clinical condition improved gradually after administration of steroids and therapy with clarithromycin. Further sequencing of Legionella DNA led to the identification of Legionella waltersii. This Legionella species has never been described as a human pathogen before. CONCLUSION: For the first time, L. waltersii was identified as a cause of severe pneumonia. Since L. waltersii is not detected by routine laboratory tests, it may be speculated that these bacteria, like other Legionella species, are underestimated as a probable cause of community-acquired pneumonia.


Community-acquired pneumonia by Legionella pneumophila serogroups 1-6 in Brazil

Chedid MB, Ilha Dde O, Chedid MF, Dalcin PR, Buzzetti M, Jaconi Saraiva P, Griza D, Menna Barreto SS.

Pulmonology Service, Hospital de Clinicas, Federal University of Rio Grande do Sul, Brazil.

Respir Med. 2005 Aug;99(8):966-75.

ABSTRACT: A prospective cohort study of adult patients hospitalized due to community-acquired pneumonia was carried out for 1 year in a Brazilian university general hospital to detect the incidence of community-acquired pneumonia by Legionella pneumophila serogroups 1-6. During a whole year, a total of 645 consecutive patients who were hospitalized due to a initial presumptive diagnosis of respiratory disease by ICD-10 (J00-J99), excluding upper respiratory diseases, were screened to detect the patients with community-acquired pneumonia. Fifty-nine consecutive patients hospitalized due to community-acquired pneumonia between July 19, 2000 and July 18, 2001, were included in the study. They had determinations of serum antibodies to L. pneumophila serogroups 1-6 by indirect immunofluorescence antibody test at the Infectious Diseases Laboratory of University of Louisville (KY, USA) and urinary antigen tests for L. pneumophila serogroup 1. Three patients had community-acquired pneumonia by L. pneumophila serogroups 1-6, two patients being diagnosed by seroconversion and positive urinary antigen tests; the other had negative serologies but strongly positive urinary antigen test. The incidence of community-acquired pneumonia by L. pneumophila serogroups 1-6 in our hospital was 5.1%.


Significance of atypical pathogens among community-acquired pneumonia adult patients admitted to hospital in Kuwait

Behbehani N, Mahmood A, Mokaddas EM, Bittar Z, Jayakrishnan B, Khadadah M, Pacsa AS, Dhar R, Chugh TD.

Department of Medicine, Kuwait University, Kuwait.

Med Princ Pract. 2005 Jul-Aug;14(4):235-40.

ABSTRACT: OBJECTIVES: The aim of this study is to determine the microbial etiology and severity of community-acquired pneumonia (CAP) in Kuwait. SUBJECTS AND METHODS: The severity of consecutive adult CAP cases admitted to 3 hospitals over a 1-year period was classified according to the Pneumonia Outcome Research Team (PORT) severity index. The microbial etiology was determined using standard methods for bacteria and serological tests for atypical and viral pathogens. RESULTS: The study population was 124 of the 135 admissions; 63 female, 61 male; mean age 41.3+/-18 years. The severity class distribution was: class I 31%, class II 37%, class III 17%, class IV 13%, and class V 2%. Etiological agents were identified from 44 patients (35%), with one pathogen in 31 (25%), two in 9 (7%), and three or more in 4 (3%). The most common pathogens identified were: Mycoplasma pneumoniae in 14 patients (11%), Legionella pneumophila in 10 (8%), Chlamydia pneumoniae in 8 (6%), influenza B virus in 8 (6%), influenza A virus in 5 (4%), Haemophilus influenzae in 4 (3%), Streptococcus pneumoniae in 3 (2%), Staphylococcus aureus in 3 (2%), gram-negative enterobacteria in 5 (4%), Moraxella catarrhalis in 2 (2%), and viruses in 4 (3%). The yields from laboratory tests were 48% for paired serology, 20% from adequate sputum sample, and 3% from blood culture. CONCLUSION: Our study shows that a large percentage of mild CAP cases are admitted to hospitals in Kuwait. Atypical pathogens have a significant role in the etiology of CAP. There is overtreatment of CAP with a combination treatment consisting mainly of third-generation chephalosporins and macrolides. Copyright (c) 2005 S. Karger AG, Basel.


Impact of the 1997 revised Centers for Disease Control criteria on case rates of legionellosis in Taiwan: review of 38 cases at a teaching hospital, 1998-2002

Lay CJ, Yu KW, Chi CY, Lai CH, Wong WW, Liu CY.

Section of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, and National Yang-Ming University, Taipei, Taiwan.

J Microbiol Immunol Infect. 2005 Jun;38(3):211-7.

ABSTRACT: In 1997, the United States Centers for Disease Control and Prevention (CDC) published revised case definitions for legionellosis which eliminated the previously used category of "probable case" based on a single indirect fluorescence antibody (IFA) titer. This study evaluated the influence of revision on the case rates of legionellosis in Taiwan. From 1988 to 2002, 4615 patients with pneumonia were tested for legionellosis in our hospital. The testing methods included IFA assay for serum specimens and direct fluorescence antibody (DFA) assay for sputum specimens. Using the revised criteria, Legionnaires' disease (LD) was diagnosed by DFA in 27 cases and by IFA in 11 cases. The most common underlying conditions were cigarette smoking (44.7%), chronic obstructive pulmonary disease (28.9%) and corticosteroid use (26.3%). The clinical features were nonspecific, including fever (73.7%), dyspnea (63.2%), cough (63.2%) and leukocytosis (63.2%). The overall mortality rate was 18.4%, and the directly LD-attributable mortality rate was 10.5%. Nasogastric tube insertion, endotracheal intubation, congestive heart failure before the onset of LD, inappropriate antimicrobial therapy, respiratory failure and absence of fever during the LD course were significantly associated with LD-attributable mortality. Older age (>70 years) was not associated with higher mortality (p=0.053). Using the revised diagnostic criteria in our series, the positive rate of case identification by IFA was 0.26%, while use of the previous case definitions resulted in a positive rate of 7.6% (including probable and definitive cases). Recognition that the original CDC criteria of IFA titer >1:256 or elevation of IFA titer <4-fold in paired sera could not adequately define an LD etiology has led to a dramatic lowering of case rates among studies after the criteria revision in Taiwan and elsewhere. Assays that are faster, more sensitive and less technician dependent are needed to diagnosis this disease.


No evidence of Legionella infection in general practice patients presenting with acute respiratory infections in The Netherlands

Diederen BM, de Jong CM, Aarts I, Peeters MF, van Gageldonk-Lafeber AB, Wilbrink B, van der Zee A.

Laboratory of Medical Microbiology, St Elisabeth Hospital, Tilburg, The Netherlands.

Clin Microbiol Infect. 2005 May;11(5):410-2.

ABSTRACT: The role of Legionella spp. in the aetiology of acute respiratory infections (ARIs) is largely unknown. In this case-control study, conducted in a general practitioner setting during 2000 and 2001, nose and throat samples from patients presenting with ARIs (n = 230) and controls (n = 200) were analysed for the presence of Legionella spp. by real-time PCR. Legionella DNA was not detected in any of the cases or controls. Thus, Legionella spp. do not seem to play a role in patients presenting with ARIs, nor were they present in patients who visited their general practitioner for complaints other than ARIs.


An Outbreak of Pontiac Fever with Respiratory Distress among Workers Performing High-Pressure Cleaning at a Sugar-Beet Processing Plant

Castor ML, Wagstrom EA, Danila RN, Smith KE, Naimi TS, Besser JM, Peacock KA, Juni BA, Hunt JM, Bartkus JM, Kirkhorn SR, Lynfield R.

Minnesota Department of Health, Minneapolis, Minnesota; Epidemic Intelligence Service, Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. Present affiliation: Urban Indian Health Institute, Seattle Indian Health Board, Seattle, Washington, USA.

J Infect Dis. 2005 May 1;191(9):1530-1537.

ABSTRACT: Background. In August 2000, the Minnesota Department of Health was notified of and investigated an outbreak of febrile respiratory illness among workers at a sugar-beet processing plant.Methods. A case was defined as fever and respiratory symptoms occurring in a worker at the sugar-beet plant on or after 31 July 2000. Case patients were interviewed, medical and work records were reviewed, and clinical samples were obtained. The plant was inspected, and environmental samples were collected.Results. Fourteen of 15 case patients performed high-pressure water cleaning in the confined space of an evaporator vessel. Symptoms included fever and chills (100%), chest tightness (93%), cough (80%), and shortness of breath (73%). In case patients, median temperature was 39.4 degrees C, median oxygen saturation was 93%, and median white blood cell count was 12x103 cells/ mu L. Four (29%) of 14 case patients showed evidence of Legionella pneumophila exposure, according to serologic testing. Water sources contained up to 10(5) cfu/mL of L. pneumophila and 22,200 endotoxin units/mL.Conclusions. Outbreak features were consistent with Pontiac fever. Respiratory symptoms, which are atypical for Pontiac fever, could be attributed to a high exposure dose of L. pneumophila from confined-space aerosolization or to endotoxin exposure. This outbreak demonstrates the potential occupational hazards for those performing high-pressure cleaning in confined spaces.


An Asian study on the prevalence of atypical respiratory pathogens in community-acquired pneumonia

Ngeow YF, Suwanjutha S, Chantarojanasriri T, Wang F, Saniel M, Alejandria M, Hsueh PR, Ping-Ing L, Park SC, Sohn JW, Aziah AM, Liu Y, Seto WH, Ngan CC, Hadiarto M, Hood A, Cheong YM.

University Malaya Medical Centre, Petaling Jaya, Malaysia.

Int J Infect Dis. 2005 May;9(3):144-53.

ABSTRACT: BACKGROUND: In many parts of Asia, the inaccessibility and high cost of diagnostic tests have hampered the study of community-acquired pneumonia (CAP) caused by atypical respiratory pathogens. OBJECTIVE:: This surveillance study examined the frequency of infection with Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila in 1756 patients presenting with signs and symptoms of CAP at 12 medical centres in Asia, using standardised laboratory techniques and interpretation criteria in all participating centres. METHODS:: Diagnosis of current infection was based on significant changes in antibody titer or persisting high antibody titers, together with the presence of bacterial DNA in respiratory secretions, in the case of M. pneumoniae and C. pneumoniae infections, or bacterial antigen in urine, in the case of L. pneumophila serogroup 1 infection. RESULTS:: Using these criteria, results from 1374 patients with paired sera showed that, overall, 23.5% of CAP cases were associated with infection with atypical respiratory pathogens, with M. pneumoniae, C. pneumoniae, and L. pneumophila being found in 12.2%, 4.7%, and 6.6% of cases, respectively. Persisting high antibody titers indicative of past exposure to M. pneumoniae, C. pneumoniae, and L. pneumophila were seen in 10.2%, 4.8%, and 18.9% of patients, respectively. CONCLUSION:: These data reflect the overall high prevalence of these atypical pathogens among Asian patients with CAP.


Pneumonia associated with HIV infection

Feldman C.

Division of Pulmonology, Department of Medicine, Johannesburg Hospital and University of the Witwatersrand, Johannesburg, South Africa.

Curr Opin Infect Dis. 2005 Apr;18(2):165-70.

ABSTRACT: PURPOSE OF REVIEW: Pneumonia occurs commonly in HIV-infected patients and this review highlights some of the recent findings in the epidemiology, pathogenesis, clinical features, treatment and prevention of this condition. RECENT FINDINGS: Pneumonia remains an important cause of morbidity and mortality in HIV-infected patients. A number of factors have been identified that increase the risk of pneumonia. Cigarette smoking increases the risk of lung colonization, as well acute pneumonia due to Pneumocystis jiroveci, and has been documented to produce significant depression of the phagocytic function of alveolar macrophages in HIV-infected patients, which may underlie this risk. Legionella pneumophila infections appear to be uncommon in HIV-infected patients, while pneumonia with Streptococcus pneumoniae continues to occur with regularity, including infections with antibiotic-resistant isolates. Pneumocystis pneumonia occurs with a low incidence in patients receiving HAART, once the CD4 count increases to over 200 microl. Studies of invasive pneumococcal infections (predominantly pneumonia) indicate that in critically ill cases, including HIV-seropositive patients, combination antibiotic therapy is associated with a lower mortality than monotherapy. The 23-polyvalent pneumococcal vaccine has been shown to reduce the risk of pneumococcal infection in HIV-infected adults receiving HAART, and a 9-valent conjugate pneumococcal vaccine has been shown to reduce the incidence of radiologically confirmed pneumonia in HIV-seropositive and HIV-seronegative children. SUMMARY: Pneumonia remains an important condition in HIV-infected patients, but recent studies demonstrate that antibiotic prophylaxis, the introduction of HAART, recognition of specific risk factors, new antibiotic treatment strategies and effective vaccines should serve to decrease its impact.


The challenges were legion

Fraser DW.

Lancet Infect Dis. 2005 Apr;5(4):237-41.

ABSTRACT: The search for the cause of the large outbreak of severe pneumonia that affected attendees of a convention of war veterans in Philadelphia in 1976 was complicated by a number of factors. The 2-10 day incubation period meant that cases were dispersed across Pennsylvania at time of onset, and matters were further complicated by the lack of a centralised record of attendance of the convention. Known methods for culture, serology, tissue staining, and toxicology gave negative results. The reliance on a clinical case definition, and the need to coordinate local, state, and federal jurisdictions both hindered efforts. Intense public scrutiny, anxiety, and promotion of implausible theories, researchers' memories of prior unsolved major investigations, and the inherent difficulty of documenting airborne spread also had an impact. The novel bacterial agent Legionella pneumophila was identified and its spread defined by persistent application of basic epidemiological and laboratory principles, including the willingness to re-examine one's assumptions.


Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila in Elderly Patients With Stroke (C-PEPS, M-PEPS, L-PEPS). A Case-Control Study on the Infectious Burden of Atypical Respiratory Pathogens in Elderly Patients With Acute Cerebrovascular Disease

Ngeh J, Goodbourn C.

From the Department of Geriatric and Stroke Medicine, Warwick Hospital, Warwick, and Department of Microbiology, Whipps Cross University Hospital, London, UK.

Stroke. 2005 Feb;36(2):259-65.

ABSTRACT: Multiple studies have suggested an association between Chlamydia pneumoniae and Mycoplasma pneumoniae infection and cardiovascular disease. We investigated whether the risk of cerebrovascular disease is associated with Legionella pneumophila infection and the aggregate number/infectious burden of these atypical respiratory pathogens. METHODS: One hundred patients aged >65 years admitted with acute stroke or transient ischemic attack (TIA) and 87 control patients admitted concurrently with acute noncardiopulmonary, noninfective conditions were recruited prospectively. Using enzyme-linked immunosorbent assay (ELISA) kits, we previously reported the seroprevalences of C pneumoniae and M pneumoniae in these patients. We have now determined the seroprevalences of L pneumophila IgG and IgM in this cohort of patients using ELISA. RESULTS: The seroprevalences of L pneumophila IgG and IgM were 29% (n=91) and 12% (n=81) in the stroke/TIA group and 22% (n=86) and 10% (n=72) in the controls, respectively. Using logistic regression to adjust for age, sex, hypertension, smoking, diabetes, ischemic heart disease, and ischemic ECG, the odds ratios for stroke/TIA in relation to L pneumophila IgG and IgM were 1.52 (95% CI, 0.70 to 3.28; P=0.29) and 1.49 (95% CI, 0.45 to 4.90; P=0.51), respectively. The odds ratios in relation to IgG seropositivity for 1, 2, or 3 atypical respiratory pathogens after adjustment were 3.89 (95% CI, 1.13 to 13.33), 2.00 (95% CI, 0.64 to 6.21), and 6.67 (95% CI, 1.22 to 37.04), respectively (P=0.06). CONCLUSIONS: L pneumophila seropositivity is not significantly associated with stroke/TIA. However, the risk of stroke/TIA appears to be associated with the aggregate number of chronic infectious burden of atypical respiratory pathogens such as C pneumoniae, M pneumoniae, and L pneumophila.  


Legionellosis in Apulia (Italy): an underevaluated disease

Montagna MT, Napoli C, Tato D, Spilotros G, Como D, Barbuti S.

DIMIMP, Sez. di Igiene, Università degli Studi di Bari.

Ann Ig. 2005 Jan-Feb;17(1):3-9.

ABSTRACT: The frequent occurrence of Legionnaires' disease outbreaks in many countries, including Italy, highlights the importance of epidemiological investigations on this disease. For this purpose, an active surveillance programme of pneumonia patients was carried out in a large hospital in Apulia (Italy) from March 2001 to December 2003. A total of 612 patients were tested for Legionella pneumophila infection by urinary antigen detection and evaluation of antibodies titre. Culture of respiratory specimens was performed on 117 patients. Thirty-seven patients (6%) tested positive for legionellosis: 10 resulted nosocomial cases and 27 as community-acquired. Only 9 cases di Legionella pneumophila infection were reported from Apulia to the routine surveillance system between 1996 and 2000. The results of our study denote the level of underestimation of this disease in Apulia.


Legionella Pneumonia and Serum Procalcitonin

Franzin L, Cabodi D.

Infectious Diseases Unit, University of Turin , Corso Svizzera 164, Turin , 10149, Italy.

Curr Microbiol. 2005 Jan;50(1):43-6.

ABSTRACT: Procalcitonin is a specific marker of severe bacterial infections with systemic inflammation. Quantitative evaluation of serum procalcitonin was performed in 140 patients with Legionella pneumonia. Positive values (>0.5 ng/mL) were found in 57.1% of the subjects. The positive sample rate was higher in early sera (73.9% in the first week) and decreased progressively. Mean values and the positive sample rate (69.8%) were higher in sera collected in the first 2 weeks of disease. Procalcitonin was positive in 86.7% of legionellosis cases confirmed by culture and mean positive values were significantly higher (P < 0.001) than those of culture-negative subjects. We conclude that procalcitonin can represent a useful prognostic marker for severe suspected Legionella pneumonia in the first 2 weeks of disease.


Legionella pneumonia: experience in a community teaching hospital

Okoye O, Tannous M, Shekar R, Ravakhah K.

Infect Control Hosp Epidemiol. 2004 Dec;25(12):1014.



Environmental cultures and hospital-acquired Legionnaires' disease: a 5-year prospective study in 20 hospitals in Catalonia , Spain

Sabria M, Modol JM, Garcia-Nunez M, Reynaga E, Pedro-Botet ML, Sopena N, Rey-Joly C.

Infectious Diseases Section, Hospital Universitari Germans Trias i Pujol, Universitat Autonoma de Barcelona, Badalona , Spain.

Infect Control Hosp Epidemiol. 2004 Dec;25(12):1072-6.

ABSTRACT: OBJECTIVE: To determine whether environmental cultures for Legionella increase the index of suspicion for legionnaires' disease (LD). DESIGN: Five-year prospective study. SETTING: Twenty hospitals in Catalonia , Spain . METHODS: From 1994 to 1996, the potable water systems of 20 hospitals in Catalonia were tested for Legionella. Cases of hospital-acquired LD and availability of an "in-house" Legionella test in the previous 4 years were assessed. After the hospitals were informed of the results of their water cultures, a prospective 5-year-study was conducted focusing on the detection of new cases of nosocomial legionellosis and the availability and use of Legionella testing. RESULTS: Before environmental cultures were started, only one hospital had conducted active surveillance of hospital-acquired pneumonia and used Legionella tests including Legionella urinary antigen in all pneumonia cases. Only one other hospital had used the latter test at all. In six hospitals, Legionella tests had been completely unavailable. Cases of nosocomial LD had been diagnosed in the previous 4 years in only two hospitals. During prospective surveillance, 12 hospitals (60%) used Legionella urinary antigen testing in house and 11 (55%) found cases of nosocomial legionellosis, representing 64.7% (11 of 17) of those with positive water cultures. Hospitals with negative water cultures did not find nosocomial LD. CONCLUSIONS: The environmental study increased the index of suspicion for nosocomial LD. The number of cases of nosocomial LD increased significantly during the prospective follow-up period, and most hospitals began using the Legionella urinary antigen test in their laboratories.


Domestic exposure to legionellae for Dutch Legionnaires' disease patients

Verhoef LP, Yzerman EP, Bruin JP, Den Boer JW.

Municipal Health Service Kennemerland Haarlem, The Netherlands.

Arch Environ Health. 2004 Nov;59(11):597-603.

The source of infection for travelers who develop Legionnaires' disease (LD) shortly after a journey abroad is difficult to ascertain. Infection is likely to have occurred abroad, but could also have occurred at the patient's own residence. The authors conducted a case-control study to determine risk for acquiring LD at home in the Netherlands after traveling abroad. They compared homes of 44 traveling LD patients with 44 homes of nontraveling LD patients, using logistic regression models. Geographic distribution was confounding the association between traveling and presence of Legionella spp. in residences; adjustment was necessary. In traveler's homes, legionellae were present more often, with crude and adjusted OR (95% CI) being 1.6 (0.5-5.0) and 1.4 (0.4-4.4), respectively. The authors' findings indicate that the patient's residence can be a potential source of infection after traveling.


Surveillance for waterborne-disease outbreaks associated with drinking water--United States, 2001-2002

Blackburn BG, Craun GF, Yoder JS, Hill V, Calderon RL, Chen N, Lee SH, Levy DA, Beach MJ.

Division of Parasitic Diseases, National Center for Infectious Diseases, CDC, USA.

MMWR Surveill Summ. 2004 Oct 22;53(8):23-45.

ABSTRACT: PROBLEM/CONDITION: Since 1971, CDC, the U.S. Environmental Protection Agency, and the Council of State and Territorial Epidemiologists have maintained a collaborative surveillance system for collecting and periodically reporting data related to occurrences and causes of waterborne-disease outbreaks (WBDOs). This surveillance system is the primary source of data concerning the scope and effects of waterborne disease outbreaks on persons in the United States. REPORTING PERIOD COVERED: This summary includes data on WBDOs associated with drinking water that occurred during January 2001-December 2002 and on three previously unreported outbreaks that occurred during 2000. DESCRIPTION OF SYSTEM: Public health departments in the states, territories, localities, and the Freely Associated States are primarily responsible for detecting and investigating WBDOs and voluntarily reporting them to CDC on a standard form. The surveillance system includes data for outbreaks associated with both drinking water and recreational water; only outbreaks associated with drinking water are reported in this summary. RESULTS: During 2001-2002, a total of 31 WBDOs associated with drinking water were reported by 19 states. These 31 outbreaks caused illness among an estimated 1,020 persons and were linked to seven deaths. The microbe or chemical that caused the outbreak was identified for 24 (77.4%) of the 31 outbreaks. Of the 24 identified outbreaks, 19 (79.2%) were associated with pathogens, and five (20.8%) were associated with acute chemical poisonings. Five outbreaks were caused by norovirus, five by parasites, and three by non-Legionella bacteria. All seven outbreaks involving acute gastrointestinal illness of unknown etiology were suspected of having an infectious cause. For the first time, this MMWR Surveillance Summary includes drinking water-associated outbreaks of Legionnaires disease (LD); six outbreaks of LD occurred during 2001-2002. Of the 25 non-Legionella associated outbreaks, 23 (92.0%) were reported in systems that used groundwater sources; nine (39.1%) of these 23 groundwater outbreaks were associated with private noncommunity wells that were not regulated by EPA. INTERPRETATION: The number of drinking water-associated outbreaks decreased from 39 during 1999-2000 to 31 during 2001-2002. Two (8.0%) outbreaks associated with surface water occurred during 2001-2002; neither was associated with consumption of untreated water. The number of outbreaks associated with groundwater sources decreased from 28 during 1999-2000 to 23 during 2001-2002; however, the proportion of such outbreaks increased from 73.7% to 92.0%. The number of outbreaks associated with untreated groundwater decreased from 17 (44.7%) during 1999-2000 to 10 (40.0%) during 2001-2002. Outbreaks associated with private, unregulated wells remained relatively stable, although more outbreaks involving private, treated wells were reported during 2001-2002. Because the only groundwater systems that are required to disinfect their water supplies are public systems under the influence of surface water, these findings support EPA's development of a groundwater rule that specifies when corrective action (including disinfection) is required. PUBLIC HEALTH ACTION: CDC and EPA use surveillance data 1) to identify the types of water systems, their deficiencies, and the etiologic agents associated with outbreaks and 2) to evaluate the adequacy of technologies for providing safe drinking water. Surveillance data are used also to establish research priorities, which can lead to improved water-quality regulations. CDC and EPA recently completed epidemiologic studies that assess the level of waterborne illness attributable to municipal drinking water in nonoutbreak conditions. The decrease in outbreaks in surface water systems is attributable primarily to implementation of provisions of EPA rules enacted since the late 1980s. Rules under development by EPA are expected to protect the public further from microbial contaminants while addressing risk tradeoffs of disinfection byproducts in drinking water.


Risk of exposure to Legionella in dental practice

Szymanska J

AAEM Editors, Instytut Medycyny Wsi, Jaczewskiego 2, P.O. Box 185, 20-950 Lublin, Poland.

Ann Agric Environ Med. 2004;11(1):9-12.

ABSTRACT: Aerosols generated in dental operations are a source of exposure to microorganisms proliferated within dental unit waterlines (DUWL) biofilm. It has been suggested that presence of Legionella species in these aerosols may contribute to potential health hazards for dental staff and patients. The article attempts to provide a brief overview of the current knowledge about Legionella, its prevalence in DUWL, immunological reactions of the dentists and concepts for prophylaxis of Legionella in dentists' work place.  


Atypical pathogens and respiratory tract infections

Blasi F.

Institute of Respiratory Diseases, University of Milan, IRCCS Ospedale Maggiore, Milan, Italy.

Eur Respir J. 2004 Jul;24(1):171-81.

ABSTRACT: The atypical respiratory pathogens Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila are now recognised as a significant cause of acute respiratory-tract infections, implicated in community-acquired pneumonia, acute exacerbations of chronic bronchitis, asthma, and less frequently, upper respiratory-tract infections. Chronic infection with C. pneumoniae is common among patients with chronic obstructive pulmonary disease and may also play a role in the natural history of asthma, including exacerbations. The lack of a gold standard for diagnosis of these pathogens still handicaps the current understanding of their true prevalence and role in the pathogenesis of acute and chronic respiratory infections. While molecular diagnostic techniques, such as polymerase chain reaction, offer improvements in sensitivity, specificity and rapidity over culture and serology, the need remains for a consistent and reproducible diagnostic technique, available to all microbiology laboratories. Current treatment guidelines for community-acquired pneumonia recognise the importance of atypical respiratory pathogens in its aetiology, for which macrolides are considered suitable first-line agents. The value of atypical coverage in antibiotic therapy for acute exacerbations of chronic bronchitis and exacerbations of asthma is less clear, while there is no evidence to suggest that atypical pathogens should be covered in antibiotic treatment of upper respiratory-tract infections.


Seroprevalence of antibodies to legionella pneumophila in hemodialysis patients

Ongut G, Yavuz A, Ogunc D, Tuncer M, Ozturk F, Mutlu D, Donmez L, Colak D, Ersoy F, Yakupoglu G, Gultekin M.

Department of Clinical Microbiology, Akdeniz University, Antalya, Turkey.

Transplant Proc. 2004 Jan-Feb;36(1):44-6.

ABSTRACT: Patients with chronic renal failure are at increased risk for infections because of impaired cellular immunity. This study was designed to determine the prevalence of antibodies to Legionella pneumophila serogroups 1 to 6 and to evaluate the possible risk factors for Legionnaires' disease in hemodialysis patients. Serum samples to be screened for antibodies against L pneumophila and risk factor data were collected from 252 hemodialysis patients. The overall prevalence of L pneumophila antibodies in hemodialysis patients was found to be 5.16% There was no statistically significant difference between L pneumophila seropositivity and potential risk factors. Further studies are needed to determine possible risk factors for Legionnaires' disease in hemodialysis patients.


A 3-year follow-up study of anti-legionella antibodies in users of Japanese 24-hour hot water baths

Irie M, Miyamoto H, Ikeda M, Yoshida S.

Institute of Health Science, Kyushu University, Japan.

J Occup Health. 2004 Jan;46(1):68-77.

ABSTRACT: Although it has been found that legionellae can exist in a 24-h hot water bath (24HHWB), which has been used recently in Japan, whether longer use of the 24HHWB causes legionellosis is unclear. The present longitudinal study was conducted in 2000 to investigate the 3-yr change in antibody titers in association with the continuous use, non-use, or canceling the use of the 24HHWB, and possible factors relating to the antibody changes. Ninety-two subjects (85 males and 7 females), who had had their anti-Legionella pneumophila (Lp) serum antibody titers measured in our initial study in 1997 and consented to blood sampling 3 yr later, were selected as subjects. There were no clinical cases who had experienced Legionnaires' disease or Pontiac fever during the 3 yr. The continuous users showed no significant changes in antibody titers within 3 yr, whereas the continuous non-users had a significant increase in antibody titers against the Lp serogroup (SG) 5 and 6. Eleven ex-users of the 24HHWB showed a significant decrease in antibody titers against Lp SG 6. The changes in the 24HHWB use, job sector, stress coping strategies, and alcohol-drinking habit were associated with the changes in antibody titers against Lp SG 1, 5 or 6. The anti-Lp antibodies were considered to be IgM dominant. In conclusion, this study indicates that 24HHWB use by healthy subjects does not tend to result in a higher onset risk of legionellosis, even if it is continuously used for 3 yr, although 24HHWB use is likely to induce production of antibodies against legionellae.


Environmental diffusion of Legionella spp and legionellosis frequency among patients with pneumonia: preliminary results of a multicentric Italian survey

Borella P, Montagna MT, Romano-Spica V, Stampi S, Stancanelli G, Triassi M, Bargellini A, Giacobazzi P, Vercilli F, Scaltriti S, Marchesi I, Napoli C, Tato D, Spilotros G, Paglionico N, Quaranta G, Branca M, Tumbarello M, Laurenti P, Moscato U, Capoluongo E, De Luca G, Legnani PP, Leoni E, Sacchetti R, Zanetti F, Moro M, Ossi C, Lopalco L, Santarpia R, Conturso V, Ribera d'Alcala G, Montegrosso S.

Dipartimento di Scienze Igienistiche, Microbiologiche e Biostatistiche, Universita degli Studi di Modena e Reggio Emilia.

ABSTRACT: A multicentric Italian investigation on legionnaires' disease is in course to clarify host factors as well as pathogen associated characteristics involved in the infection/disease. The main goal of the research plan is to account for some critical aspects concerning identification and prevention of legionellosis. To improve knowledge on factors associated with Legionella spp colonisation in hot waters, to detect cases and to characterize risk factors in subjects which develop pneumonia are specific objectives of the research programme. Preliminary results show that hot waters of houses and hotels are frequently contaminated (22.6% and 54.6%, respectively), mainly by L. pneumophila. Microbial concentrations were low in domestic waters (<1.000 ufc/l), but higher in samples from the hotels (geom. mean 1.85 x 10(3) ufc/l). Warming system, age of the plant, type of building were risk factors significantly associated with Legionella spp positivity. The active surveillance on patients affected by pneumonia with search for Legionella urinary antigen allowed the identification of 34 cases, 3 of which of nosocomial origin, corresponding to 4.2% of the screened pneumonia. After informed consent, 26 subjects were recruited for a case-control-study to clarify risk factors for the disease.

Annali Igiene 2003:15:493-503. 


The discharge form: advantages and limits legionellosis cases individuation

Trerotoli P, Montagna MT, Borella P, Romano Spica V, Stancanelli G, Triassi M, Serio G, Napoli C, Soldano S, Tato D, Vercilli F, Gentile C, Quaranta G, Volpe M, Ambrosio A, Santarpia R, Montegrosso S.

Dipartimento di Medicina Interna e Medicina Pubblica, Sezione di Igiene, Universita degli Studi di Bari.

Ann Ig. 2003 Nov-Dec;15(6):817-24.

ABSTRACT: Despite legionellosis surveillance is active in Italy since many years, the disease notification appears still undervalued. A multicentric survey was carried out among 5 big Italian hospitals. It examined 11,435 discharge forms (1999-2001), reporting pneumonia diagnosis. Legionellosis (II class of notify system for infectious disease) was studied among pneumonia diagnosis by discharge forms. According to the ICD9-CM, there's no specific code for legionellosis (this disease is included among "others gram-negative pneumonia"). So the presumed pneumonia imputable to Legionella spp were the 2.7% of the whole number of analyzed discharge forms. Besides, the data regarding the other pneumonia showed that the etiological agent was specified only in the 11.2% of the case. This situation could be rectified both introducing adequate discharge forms codes and promoting the etiological diagnosis during the hospital stay.  


Prevalence of legionella waterline contamination and Legionella pneumophila antibodies in general dental practitioners in London and rural Northern Ireland
Pankhurst CL, Coulter W, Philpott-Howard JJ, Harrison T, Warburton F, Platt S, Surman S, Challacombe S.

1Specialist in Oral Microbiology, Division of Oral Medicine, Pathology, and Immunology, Guy's, King's St Thomas' Dental Institute, Guy's Campus, London SE 9RT.

Br Dent J. 2003 Nov 22;195(10):591-4.

ABSTRACT: OBJECTIVES: To determine the prevalence of legionellae in dental unit waterlines (DUWL) in general dental practices in London and rural Northern Ireland and whether the organism occurs at a high enough frequency and magnitude in DUWL to represent a threat to dentists' health. MATERIALS AND METHOD: Two hundred and sixty six (166 London, 100 Northern Ireland) randomly selected dental surgeries were recruited. Standardised 250 ml water samples were taken from the DUWL and 1 litre samples from the surgery cold water tap to measure the prevalence of legionellae. The dentists provided a blood sample for legionella serology. RESULTS: The prevalence of legionellae was very low (0.37%). Legionellae were not isolated from DUWL or surgery basin taps in Northern Ireland. Legionella spp were isolated from the DUWL and surgery basin of one practice in London and from the cold water supply of a further three practices. The prevalence of Legionella pneumophila antibodies was less than that seen in a comparable group of London blood donors. CONCLUSION: The risk to dentists' health from potential exposure to legionellae in this cohort of dentists was very low and this was confirmed by the very low seroprevalence and antibody titres to legionella detected in the dentists.


Repeat capture-recapture studies as part of the evaluation of the surveillance of Legionnaires' disease in France

Nardone A, Decludt B, Jarraud S, Etienne J, Hubert B, Infuso A, Gallay A, Desenclos JC.

Institut de Veille Sanitaire, Saint-Maurice, France.

Epidemiol Infect. 2003 Aug;131(1):647-54.

ABSTRACT: We evaluated improvements made to the mandatory notification surveillance system for Legionnaires' disease in France by estimating its sensitivity in 1995 and 1998 using a repeat capture-recapture method. A case of Legionnaires' disease was defined as a person treated for pneumonia in whom legionella had been detected. Patient details were collected from (1) mandatory notifications; (2) the National Reference Centre for Legionella; (3) a postal survey of all hospital laboratories. The three sources were cross-matched and 715 individual cases were identified. A log-linear model, which included an interaction term between mandatory notifications and both the National Reference Centre and Laboratory sources, provided an estimated total of 1124 cases (95% CI 973-1275) in 1998, a twofold increase compared with 1995. The sensitivity of the surveillance system improved from 10% in 1995 to 33% (95% CI 29-38%) in 1998. Capture-recapture methods are important tools in the evaluation of surveillance systems.  


Legionnaires disease and HIV infection

Pedro-Botet ML, Sabria M, Sopena N, Garcia-Nunez M, Dominguez MJ, Reynaga E, Rey-Joly C.

Infectious Disease Unit, University Hospital Germans Trias i Pujol, Universitat Autonoma, Badalona, Spain.

Chest. 2003 Aug;124(2):543-7.

ABSTRACT: STUDY OBJECTIVES: To compare the outcome of Legionnaires disease (LD) in patients with and without HIV infection. DESIGN: Retrospective review of clinical charts. SETTING: Six hundred-bed university hospital. PATIENTS: We studied the clinical findings of 64 patients without HIV and 15 patients with HIV. Patients with a serologic diagnosis only were not included. Patients with previous immunosuppressive therapy or transplant recipients were excluded from the former group. In the HIV group, the mean CD4 cell count was 347.5/ microL, plasma viral load was undetectable in 50% of the patients, and only one patient (7%) was receiving cotrimoxazole as prophylaxis against Pneumocystis carinii at the time of pneumonia. No differences were observed in the two groups with respect to community or nosocomial acquisition, delay in the initiation of appropriate treatment, the use of macrolides or fluoroquinolones, and Fine score in cases of community-acquired LD. RESULTS: Univariate analysis showed that time to apyrexia was longer, and respiratory symptoms, bilateral infiltrates in chest radiograph, hyponatremia, increase in aspartate aminotransferase and creatine phosphokinase (CK), and respiratory failure were more frequent in the HIV group. Mortality was greater in patients with HIV, achieving a statistically significant value of 20%; however, multivariate analysis only confirmed these differences with respect to the increase in CK. CONCLUSIONS: LD has a more severe clinical presentation and worse evolution in patients with HIV.


Clinical and epidemiologic investigation of two Legionella-Rickettsia co-infections

Huerta M, Castel H, Grotto I, Shpilberg O, Alkan M, Harman-Boehm I.

Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.

Isr Med Assoc J. 2003 Aug;5(8):560-3.

ABSTRACT: BACKGROUND: We treated two patients diagnosed with legionellosis and simultaneous Rickettsia conorii co-infection. OBJECTIVES: To report the clinical and laboratory characteristics of this unusual combination, and to describe the execution and results of our environmental and epidemiologic investigations. METHODS: Serial serologic testing was conducted 1, 4 and 7 weeks after initial presentation. Water samples from the patients' residence were cultured for Legionella. Follow-up cultures were taken from identical points at 2 weeks and at 3 months after the initial survey. RESULTS: Both patients initially expressed a non-specific rise in anti-Legionella immunoglobulin M titers to multiple serotypes. By week 4 a definite pattern of specifically elevated IgG titers became apparent, with patient 1 demonstrating a rise in specific anti-L. pneumophila 12 IgG titer and patient 2 an identical response to L. jordanis. At 4 weeks both patients were positive for both IgM and IgG anti-R. conorii antibodies at a titer > or = 1:100. Heavy growth of Legionella was found in water sampled from the shower heads in the rooms of both patients. Indirect immunofluorescence of water cultures was positive for L. pneumophila 12 and for L. jordanis. CONCLUSIONS: Although most cases of community-acquired Legionella pneumonia in our region appear simultaneously with at least one other causative agent, co-infection with R. conorii is unusual and has not been reported to date. This report illustrates the importance of cooperation between clinicians and public health practitioners.


Legionnaires' disease

Gould D.

School of Nursing, City University, London.

Nurs Stand. 2003 Jul 23-29;17(45):41-4.

ABSTRACT: This article describes the environmental sources and transmission of Legionella pneumophila, outlines the factors that place certain groups of patients at particular risk, documents a number of outbreaks of legionellosis that have received media attention and explains the most important preventative strategies currently employed in the UK. Implications for the nurse's role, plus individual and public health are addressed.


Legionella pneumophila serogroup 1 strain Paris: endemic distribution throughout France

Aurell H, Etienne J, Forey F, Reyrolle M, Girardo P, Farge P, Decludt B, Campese C, Vandenesch F, Jarraud S.

Centre National de Reference des Legionella, INSERM E-0230, Laboratoire de Bacteriologie, Faculte de Medecine Laennec IFR 62, 69372 Lyon Cedex 08, France.

J Clin Microbiol. 2003 Jul;41(7):3320-2.

ABSTRACT: An analysis of 691 French clinical Legionella isolates showed that the endemic L. pneumophila serogroup 1 strain Paris was responsible for 12.2% of all cases of legionellosis and had a specific pulsed-field gel electrophoresis pattern. We also demonstrated the presence of this endemic clone throughout Europe.


Legionella spp.: community acquired and nosocomial infections

Roig J, Sabria M, Pedro-Botet M-L.

Pulmonary Division, Nostra Senyora de Meritxell Hospital, Escaldes, Principality of Andorra, Infectious Disease Department, Germans Trias I Pujol University Hospital, Badalona, Barcelona, Spain.

Curr Opin Infect Dis. 2003 Apr; 16(2): 145-51

ABSTRACT: PURPOSE OF REVIEW: The key points of this review are the increasingly recognized risk of home-acquired Legionnaires' disease; the significance and potential pathogenic role of other species of Legionella spp., different from L. pneumophila, and of other microorganisms that are phylogenetically close to Legionella and that have been named as Legionella-like amoebal pathogens; the breakthrough in the diagnosis of the disease caused by new commercially available urine antigen detection tests; the controversy over sensitivity and specificity of serological diagnostic methods; the recognition of a variety of possible mixed infections, particularly in the immunocompromised population; and new and controversial aspects of the therapeutic approach to legionellosis. RECENT FINDINGS: During the last year a number of articles have provided clinically relevant insights into our knowledge of Legionnaires' disease. In view of the fact that Legionella spp. have progressively become recognized as relatively common causative agents of both community-acquired and nosocomial legionellosis, this is an opportune moment for this review. SUMMARY: If domestic aquatic reservoirs were eventually confirmed as significant agents of transmission of legionellosis, the adoption of preventive measures would then be crucial. The progressive identification of other species, different from L. pneumophila, as causative agents of pneumonia should both encourage microbiologists and clinicians to improve their diagnostic methodology and increase the awareness of these infections. Finally, the awareness of mixed infections, probably far more severe and perhaps not so uncommon as previously thought, has important clinical connotations for both the diagnostic and the therapeutic approach to legionellosis in the immunosuppressed host, particularly in those cases of delayed clinical resolution.