Prevenzione (aprile 2003 - aprile 2012)

Plan for the control of Legionella infections in long-term care facilities: Role of environmental monitoring

Cristino S, Legnani PP, Leoni E.

Department of Medicine and Public Health, University of Bologna, Bologna, Italy.

nt J Hyg Environ Health. 2012 Apr;215(3):279-85.

ABSTRACT: In accordance with the international and national guidelines, the Emilia-Romagna Region (Italy) has established regional guidelines for the surveillance and prevention of legionellosis based on the concept of risk assessment, with particular attention to environmental monitoring. The aim of this study was to verify how environmental surveillance in the context of risk assessment plans could help to guide decisions about preventive strategies against Legionella infections in Long Term Care Facilities (LTCF). In six LTCFs in the city of Bologna (Emilia-Romagna Region) a self-control plan was implemented that included the environmental monitoring of Legionella spp. and the surveillance of hospital-acquired Legionnaires' Disease. At baseline, four hot water systems were colonized by Legionella pneumophila (3 LCTFs) and Legionella londiniensis (1 LCTF). In each establishment specific control measures were adopted based on the characteristics of the system, the virulence of the strain and the level of the contamination. The monitoring, carried out for around two years, was also extended to the ways in which the system and the distal water distribution points were used and maintained with respect to the good practices in operation and management. The adopted actions (shock and/or continuous disinfection treatments) and the implementation of the good practice measures reduced the contamination to acceptable and stable levels. No cases of hospital-acquired legionellosis occurred during the period of study. The environmental surveillance was successful in evaluating the risk and identifying the most suitable preventive strategies.


Epidemiological investigation of a legionellosis outbreak in a Slovenian nursing home, August 2010

Trop Skaza A, Beskovnik L, Storman A, Kese D, Ursic S.

Institute of Public Health Celje, Celje, Slovenia.

Scand J Infect Dis. 2012 Apr;44(4):263-9.

ABSTRACT: Background: August 2010 marked the beginning of the largest outbreak of legionellosis in a Slovenian nursing home. This article presents our experiences with the outbreak investigation. Methods: In order to collect the necessary patient epidemiological data, we used individual epidemiological questionnaires. Samples were available from 15 patients and were subject to laboratory investigation. Urine and sputum samples were difficult to obtain due to the underlying diseases of the patients. Serological diagnostics constituted an important part of the epidemiological investigation. Sixty-four environmental samples were taken to identify the sources of infection. By genotyping, we assessed the affinity of the allelic profile of Legionella pneumophila serogroup 1 in environmental samples and in patient samples. Results: Legionnaires' disease was diagnosed in 10 patients based on a combination of various tests. Legionella pneumophila serogroup 1, Legionella pneumophila serogroups 2-14, and Legionella sp., in concentrations of < 10 to 61,000 CFU/l, were isolated from 51 out of 64 environmental samples. The source of the outbreak was confirmed by genotyping the isolates from patients and the isolates from the water supply system. The 2 isolates had identical allelic profiles corresponding to that of L. pneumophila serogroup 1 allelic profile 2,3,9,10,2,1,6, designated sequence type 23 (according to the European Working Group for Legionella Infections). Conclusion: We describe a Legionella pneumophila serogroup 1 outbreak in a Slovenian nursing home. The source of infection was demonstrated using sequence-based typing. Water flow disturbances were determined as the most probable cause of Legionella growth. Overall, the risk of a Legionella outbreak is underestimated in Slovenia.


Legionellae in engineered systems and use of quantitative microbial risk assessment to predict exposure

Buse HY, Schoen ME, Ashbolt NJ.

National Exposure Research Laboratory, US Environmental Protection Agency, 26 W Martin Luther King Dr, MS 579, Cincinnati, OH 45268, USA.

Water Res. 2012 Mar 15;46(4):921-33. review

ABSTRACT: While it is well-established that Legionella are able to colonize engineered water systems, the number of interacting factors contributing to their occurrence, proliferation, and persistence are unclear. This review summarizes current methods used to detect and quantify legionellae as well as the current knowledge of engineered water system characteristics that both favour and promote legionellae growth. Furthermore, the use of quantitative microbial risk assessment (QMRA) models to predict potentially critical human exposures to legionellae are also discussed. Understanding the conditions favouring Legionella occurrence in engineered systems and their overall ecology (growth in these systems/biofilms, biotic interactions and release) will aid in developing new treatment technologies and/or systems that minimize or eliminate human exposure to potentially pathogenic legionellae.


Scald risk in social housing can be reduced through thermostatic control system without increasing Legionella risk: a cluster randomised trial

Edwards P, Durand MA, Hollister M, Green J, Lutchmun S, Kessel A, Roberts I.

NPHIR, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK.

Arch Dis Child. 2011 Dec;96(12):1097-102.

ABSTRACT:OBJECTIVE: To quantify the effects of a thermostatic control system in social (public) housing on the prevalence of dangerous (>60°C) water temperatures and on fuel consumption.DESIGN: Pair-matched double-blind cluster randomised controlled trial.SETTING: Social housing in a deprived inner-London borough.PARTICIPANTS: 150 households recruited as clusters from 22 social housing estates. Four small estates were combined into two clusters (resulting in a total of 10 pairs of clusters).INTERVENTION: Social housing estate boiler houses were randomised to a thermostatic control sterilisation programme (heating water to 65°C during 00:00-06:00 h and to 50°C from 06:00 to 00:00 h daily) or to standard control (constant temperature 65°C).MAIN OUTCOME MEASURES: Water temperature over 60°C ('dangerous') after running taps for 1 min and daily fuel consumption (cubic feet of gas).RESULTS: 10 clusters (80 households) were allocated to the sterilisation programme and 10 clusters (70 households) to control, of which 73 and 67 households, respectively, were analysed. Prevalence of dangerous (>60°C) hot water temperatures at 1 min was significantly reduced with the sterilisation programme (mean of cluster prevalence 1% in sterilisation programme group vs 34% in control group; absolute difference 33%, 95% CI 12% to 54%; p=0.006). Prevalence of high (>55°C) hot water temperatures at 1 min was significantly reduced (31% sterilisation vs 59% control; absolute difference 28%, 95% CI 9% to 47%; p=0.009). Gas consumption per day reduced more in the control group than in the sterilisation programme group, although not statistically significantly (p=0.125).CONCLUSIONS: The thermostatic control with daily sterilisation was effective in capping hot water temperatures and therefore reduced scald risk. Although expected to save energy, fuel consumption was increased relative to the control group.


Prevention of hospital-acquired legionellosis

Lin YE, Stout JE, Yu VL.

National Kaohsiung Normal University, Taiwan, ROC.

Curr Opin Infect Dis. 2011 Aug;24(4):350-6.

ABSTRACT: PURPOSE OF REVIEW: The incidence of hospital-acquired legionellosis appears to be increasing. Presence of Legionella in the hospital drinking water is the only risk factor known with certainty to be predictive of risk for contracting Legionnaires' disease.

RECENT FINDINGS: Given the high frequency of infection by nonpneumophila and nonserogroup 1 species, both Legionella respiratory culture on selective media and urine antigen testing should be available in the hospital clinical microbiology laboratory. If the drinking water is contaminated by nonpneumophila or nonserogroup 1 species, Legionella culture on selective media must be available for patients with hospital-acquired pneumonia. The impact of PCR application for environmental water specimen remains to be elucidated. Its advantage is that it is a rapid test and its weakness is its low specificity. Copper-silver ionization disinfection and point-of-use (POU) filters have proved effective. Chlorine dioxide and monochloramine are under evaluation and their ultimate role remains to be elucidated. Routine Legionella cultures in concert with disinfectant levels are the best indicators for ensuring long-term efficacy. Percentage distal site positivity for Legionella in drinking water is accurate in predicting risk. Quantitative criteria (CFU/ml) have proven inaccurate and should be abandoned.

SUMMARY: Infection control professionals, not healthcare facility personnel or engineers, should play the leadership role in selecting and evaluating the specific disinfection modality. Proactive measures of routine environmental cultures for hospital water and disinfection modalities allow for effective prevention of this high-profile hospital-acquired infection.


Legionella--every infection preventionist's dream--or is it?

Chafin KN, Watts MD.

Department Infection Prevention, North Central Baptist Hospital, San Antonio, Texas 78258, USA.

Crit Care Nurs Q. 2011 Jan-Mar;34(1):52-9.

ABSTRACT: Legionella is an underreported disease challenge within the hospital setting. In order to combat Legionella during times of construction and renovation, infection preventionists must become construction experts. The infection preventionist must be able to plan for potential waterborne disease outbreaks and protect the hospital staff, patients and visitors from waterborne pathogens. Legionella's history, signs and symptoms, diagnostic testing and treatment will be discussed. The hospital's convening of a multidisciplinary Legionella task force to work cohesively to develop a waterborne pathogens plan will also be discussed. This article was written from the perspective of the infection preventionist and employee health nurse at the time of the Legionella outbreak at their hospital.


A decision support system for preventing legionella disease

Yüregir OH, Oral M, Kalan O.

Faculty of Engineering and Architecture, Industrial Engineering Department, Çukurova University, Adana, 01330, Turkey,

J Med Syst. 2010 Oct;34(5):875-81.

ABSTRACT: Information systems plays an important role in medicine because it helps process more data more efficiently while providing access to more people in different parts of the world. In this research we analyzed the data of legionella pneumophila and other legionella species collected by the public hygiene center (PHC). PHC collected 7,211 water samples from different sources of different locations in different cities in Turkey from year 1995 to 2008. The main goal of this research is to develop a conceptual framework for preventing disease and to design a medical decision support system to help administration assessing the risk of Legionnaires' disease and preventing the outbreaks of the disease. The DSS involves SOM software which was programmed with C# to search for patterns and similarities in data sets by producing SOM risk maps. Thus administrators can decide where to monitor cautiously to prevent the disease.


Effective environmental sampling strategies for monitoring Legionella spp contamination in hot water systems

Ditommaso S, Giacomuzzi M, Gentile M, Moiraghi AR, Zotti CM.

Department of Public Health and Microbiology, University of Turin, Turin, Italy.

Am J Infect Control. 2010 Jun;38(5):344-9.

ABSTRACT: BACKGROUND: The prevention and control of legionellosis in hospital settings involves environmental sampling, among other measures. The data yielded by sampling constitute an important means of risk assessment and provide a valid basis on which to plan remedial (cleansing and disinfection) and preventive (maintenance) interventions. This retrospective study had 2 objectives: (1) to evaluate the utility of biofilm sampling at distal sites and (2) to identify an efficient environmental sampling strategy. METHODS: Samples of hot water and biofilm were collected between June 1999 and March 2008 from 41 hospitals in Italy's Piemonte region. We analyzed results of the samples (water and biofilm) taken from the same site and results of the water samples taken from the recirculation loop and water samples taken from the distal sites during the same sampling run. RESULTS: Microbiological analysis was performed on 3910 pairs of samples (water/biofilm). In 81% of the pairs, the results were concordant; in 17% of the pairs, Legionella was isolated only from the water samples, and in only 2% of the pairs was Legionella isolated from the biofilm sample alone. Data from 299 sampling runs show that 79% (236) of results from the water samples taken from the recirculation loop and water samples taken from the distal sites during the same sampling run were concordant, and 21% (63) were discordant. CONCLUSIONS: Our findings suggest that hospitals could safely adopt a simpler (water sampling only without biofilm sampling) and more efficient (monitoring of the entire system through sampling of recirculation loop water) environmental sampling policy.  


Venturi system could be major breakthrough

Makin T, Pride M.

Department of Medical Microbiology, Royal Liverpool and Broadgreen University Hospitals Trust.

Health Estate. 2010 Apr;64(4):27-33.

ABSTRACT: In a follow-up to last month's "Fighting the waterborne menace" article (HEJ--March 2010), Dr. Tom Makin, directorate manager, medical microbiology, at the Royal Liverpool and Broadgreen University Hospitals Trust, and Martin Pride, new business development, at Kemper U.K. & Ireland, examine how Legionella has become a significant potential issue in hospital water systems, and discuss a novel, venturi-based engineering system co-developed by Kemper and a German university, and recently successfully trialled at a Liverpool hospital, which ensures constant water circulation, significantly reducing the risk of both biofilm, and consequently Legionella, build-up.


Management of the Legionella-link risk in a multicentre area's hospital: lessons learned of a six-year experience

Lecointe D, Fagundez E, Pierron P, Musset JP, Brissé P, Vollereau D, Breton D, Théodora C, Beauvais R, Malbrunot C, Crine L, Fèvre C; Groupe de Travail "Eau et légionelles".

Unité fonctionnelle d'hygiène hospitalière et de lutte contre les infections nosocomiales, centre hospitalier Sud-Francilien, 59, boulevard Henri-Dunant, Corbeil-Essonnes, France.

Pathol Biol (Paris). 2010 Apr;58(2):131-6.

ABSTRACT: To reduce the Legionella-link risk in the several sites of Sud-Francilien Hospital, following a hospital-acquired legionellosis case, a multidisciplinary working group performed an action plan monitored through Legionella pneumophila counts in hot water supply. From 2003 to the first half year 2009, positive points for Legionella pneumophila on the main sites of the hospital decreased from 85.71 to 28.00%, representing a significant reduction of 67.33%. Similar results were observed for three of the four establishments, whereas the last did not describe a pronounced reduction of Legionella pneumophila counts and showed constantly serogroup 1 strains. During this period, investigations of additional cases of legionellosis demonstrated a nosocomial transmission in one case in this last site. Multidisciplinary mobilization in management of Legionella-link risk contributed to these results.


Survey on legislation regarding wet cooling systems in European countries

Ricketts KD, Joseph C, Lee J, Wewalka G; European Working Group for Legionella Infections

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

Euro Surveill. 2008 Sep 18;13(38). pii: 18982.

ABSTRACT: Wet cooling systems are often associated with large outbreaks of Legionnaires' disease. Several European countries have legislation for registering such systems. The authors aimed to obtain an overview of the situation in Europe. A questionnaire survey was sent to 35 of the countries that collaborate in the European Working Group for Legionella Infections. In two countries it was passed to a regional level (to three regions in both Belgium and the United Kingdom), so that 39 countries or regions were sent the survey; 37 responded. Nine countries stated having legislation for the registration of wet cooling systems. Separate legislation exists at a regional level for two regions in Belgium and all three regions in the UK, giving a total of twelve countries/regions with legislation. In nine of these countries/regions, the legislation has been introduced since 2001. All of these countries/regions require periodic microbiological monitoring between twice a year and weekly; in nine, the legislation requires periodic inspection of the systems. Regulations for the registration of wet cooling systems should be required by public health authorities. During an outbreak of legionellosis, a register of wet cooling systems can speed up the investigation process considerably. The authors believe that the European Centre for Disease Prevention and Control (ECDC) should take the initiative to propose European Community (EC) regulations for all Member States. 


Changes in prevention and outbreak management of Legionnaires disease in the Netherlands between two large outbreaks in 1999 and 2006

Sonder GJ, van den Hoek JA, Bovée LP, Aanhane FE, Worp J, Du Ry van Beest Holle M, van Steenbergen JE, den Boer JW, Ijzerman EP, Coutinho RA.

Gemeentelijke Gezondheidsdienst (GGD) Amsterdam (Public Health Service Amsterdam) Department of Infectious Diseases, Amsterdam, the Netherlands.

Euro Surveill. 2008 Sep 18;13(38). pii: 18983.

ABSTRACT: We describe an outbreak of Legionnaires' disease in 2006 in Amsterdam, the Netherlands. Comparisons with the outbreak that took place in 1999 are made to evaluate changes in legionella prevention and outbreak management. The 2006 outbreak was caused by a wet cooling tower. Thirty-one patients were reported. The outbreak was detected two days after the first patient was admitted to hospital, and the source was eliminated five days later. The 1999 outbreak was caused by a whirlpool at a flower show, and 188 patients were reported. This outbreak was detected 14 days after the first patient was admitted to hospital, and two days later the source was traced. Since 1999, the awareness of legionellosis among physicians, the availability of a urinary antigen tests and more efficient early warning and communication systems improved the efficiency of legionellosis outbreak management. For prevention, extensive legislation with clear responsibilities has been put in place. For wet cooling towers, however, legislation regarding responsibility and supervision of maintenance needs to be improved.


Role of environmental surveillance in determining the risk of hospital-acquired legionellosis: a national surveillance study with clinical correlations

Stout JE, Muder RR, Mietzner S, Wagener MM, Perri MB, DeRoos K, Goodrich D, Arnold W, Williamson T, Ruark O, Treadway C, Eckstein EC, Marshall D, Rafferty ME, Sarro K, Page J, Jenkins R, Oda G, Shimoda KJ, Zervos MJ, Bittner M, Camhi SL, Panwalker AP, Donskey CJ, Nguyen MH, Holodniy M, Yu VL; Legionella Study Group.

VA Pittsburgh Healthcare System, Pittsburgh, PA, USA.

Infect Control Hosp Epidemiol. 2007 Jul;28(7):818-24.

ABSTRACT: OBJECTIVE: Hospital-acquired Legionella pneumonia has a fatality rate of 28%, and the source is the water distribution system. Two prevention strategies have been advocated. One approach to prevention is clinical surveillance for disease without routine environmental monitoring. Another approach recommends environmental monitoring even in the absence of known cases of Legionella pneumonia. We determined the Legionella colonization status of water systems in hospitals to establish whether the results of environmental surveillance correlated with discovery of disease. None of these hospitals had previously experienced endemic hospital-acquired Legionella pneumonia. DESIGN: Cohort study. SETTING: Twenty US hospitals in 13 states. INTERVENTIONS: Hospitals performed clinical and environmental surveillance for Legionella from 2000 through 2002. All specimens were shipped to the Special Pathogens Laboratory at the Veterans Affairs Pittsburgh Medical Center. RESULTS: Legionella pneumophila and Legionella anisa were isolated from 14 (70%) of 20 hospital water systems. Of 676 environmental samples, 198 (29%) were positive for Legionella species. High-level colonization of the water system (30% or more of the distal outlets were positive for L. pneumophila) was demonstrated for 6 (43%) of the 14 hospitals with positive findings. L. pneumophila serogroup 1 was detected in 5 of these 6 hospitals, whereas 1 hospital was colonized with L. pneumophila serogroup 5. A total of 633 patients were evaluated for Legionella pneumonia from 12 (60%) of the 20 hospitals: 377 by urinary antigen testing and 577 by sputum culture. Hospital-acquired Legionella pneumonia was identified in 4 hospitals, all of which were hospitals with L. pneumophila serogroup 1 found in 30% or more of the distal outlets. No cases of disease due to other serogroups or species (L. anisa) were identified. CONCLUSION: Environmental monitoring followed by clinical surveillance was successful in uncovering previously unrecognized cases of hospital-acquired Legionella pneumonia.


Experimental based experiences with the introduction of a water safety plan for a multi-located university clinic and its efficacy according to WHO recommendations

Dyck A, Exner M, Kramer A.

Institute for Hygiene and Environmental Medicine of the Ernst-Moritz-Arndt-University, Greifswald, Germany.

BMC Public Health. 2007 Mar 13;7:34. 

BACKGROUND: Due to the high number of immunosuppressed and other predisposed patients hospitals have to control and ensure the microbiological water quality. The origin for the occurrence of pathogenic microorganisms in water pipes is the formation of biofilm. METHODS: For the permanent control of water safety a water safety plan (WSP) was realized as recommended by the WHO following the principle "search and destroy". The WSP is based on an established HACCP concept due to the special focus. The most important measures include the concept for sample taking depending on patient risk. 3 different categories) are distinguished: risk area1 (high infection risk), risk 2 (moderate infection risk), and risk area 3 (not increased infection risk). Additionally to the threshold value of the German law for the quality of drinking water (TrinkwV) three more limiting values were defined (warning, alert, and worst case) for immediate risk adapted reaction. Additional attention has to be focussed on lavatory sinks, which are an open bacterial reservoir. Therefore continuous disinfecting siphons were installed as part of the WSP in high risk areas.If extended technical equipment is not available, especially for immunocompromised patients the following measures are easy to realize: boiled (or sun exposed) water for nursing procedures as well alimentary use, no showering. RESULTS: Comparing data over 3 years the microbial water quality was significantly improved resulting in no new case of nosocomial Legionella pneumoniae and decrease in neonatal sepsis. CONCLUSION: According to average situations with highly contaminated water system the management must be defined with implementation of water task force, immediate providing of special equipment, information of patients and staff and control of the water quality, an example for successful decontamination of the hospital within 24 hours is given.


Outbreak detection and secondary prevention of Legionnaires' disease: a national approach

Den Boer JW, Verhoef L, Bencini MA, Bruin JP, Jansen R, Yzerman EP.

Municipal Health Service Kennemerland, P.O. Box 5514, 2000 GM Haarlem, The Netherlands.

Int J Hyg Environ Health. 2007 Jan;210(1):1-7.

BACKGROUND: To stop a possible outbreak of Legionnaires' disease (LD) at an early stage an outbreak detection programme was installed in The Netherlands. METHODS: The programme consisted of sampling and controlling of potential sources to which LD patients had been exposed during their incubation period. Potential sources were considered to be true sources of infection if two or more LD patients (cluster) had visited them, or if available patients' isolates and environmental Legionella spp. were indistinguishable by amplified fragment length polymorphism genotyping. RESULTS: Rapid sampling and genotyping as well as cluster recognition helped to target control measures. Despite these measures, two small outbreaks were only stopped after renewal of the water system. The combination of genotyping and cluster recognition lead to 29 of 190 (15%) patient-source associations. CONCLUSION: Systematic sampling and cluster recognition can contribute to outbreak detection and lead to cost-effective secondary prevention of Legionnaires' disease.


The impact of new guidelines in Europe for the control and prevention of travel-associated Legionnaires' disease

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

Respiratory Department, Health Protection Agency Centre for Infections, 61 Colindale Avenue, London, UK.

Int J Hyg Environ Health. 2006 Nov;209(6):547-52.

ABSTRACT: On 1 July 2002, EWGLINET introduced European guidelines for the control and prevention of travel-associated legionnaires' disease. This paper presents the results gathered by the surveillance scheme during the first two and a half years of the operation of the guidelines (to the end of 2004). Two hundred and thirty-seven new clusters and 70 cluster updates were identified. Investigations at 146 sites returned positive samples for legionella, and the proportion of positive sites reached over 60% in 2004. Thirty-four cluster sites were reported to have been investigated satisfactorily, but have gone on to be associated with subsequent cases ('repeater sites'). Fifty-one sites were published on the European Working Group for Legionella Infections (EWGLI) website; the publication states that EWGLINET cannot be confident that the sites have adequate control measures in place. The operation of the guidelines is discussed, and the situation in Turkey highlighted as a particular success.


Evaluation of standardized scored inspections for Legionnaires' disease prevention, during the Athens 2004 Olympics

Hadjichristodoulou Ch, Goutziana G, Mouchtouri V, Kapoula Ch, Konstantinidis A, Velonakis E, Vatopoulos A, Kremastinou J.

Department of Hygiene and Epidemiology, Faculty of Medicine, University of Thessalia, Larisa, Greece.

Epidemiol Infect. 2006 Oct;134(5):1074-81.

ABSTRACT: The study was designed to determine the contribution of standardized scored inspections implemented during the Athens 2004 Pre-Olympic and Olympic period, in assessing the presence of Legionella spp. in water sites. Inspection grading scores of 477 water supply systems, 127 cooling towers and 134 decorative fountains were associated with the corresponding microbiological test results of 2514 samples for Legionella spp. Nine violations of water supply systems and nine of cooling towers significantly associated with positive microbiological test results, and four violations of water supply systems and one of cooling towers were among those designated as 'critical' water safety hazards in the inspection reports. The study documents a strong correlation [water supply systems (RR 1.92), cooling towers (RR 1.94)] between unsatisfactory inspection scoring results and Legionella-positive microbiological test results (in excess of 10,000 c.f.u./l) and suggests the utility of inspection scoring systems in predicting Legionella proliferation of water systems and in preventing Legionnaires' disease.

A proactive approach to prevention of health care-acquired Legionnaires' disease: the Allegheny County (Pittsburgh) experience

Squier CL, Stout JE, Krsytofiak S, McMahon J, Wagener MM, Dixon B, Yu VL.

Association for Professionals in Infection Control and Epidemiology, Three Rivers Chapter, and Veterans Administration Pittsburgh Healthcare System, Pennsylvania, USA.

Am J Infect Control. 2005 Aug;33(6):360-7.

BACKGROUND: The Allegheny County Health Department (ACHD) in Pennsylvania distributed the first guidelines for prevention and control of health care-acquired Legionnaires' disease (LD) by 1995. The proactive approach advocated in the guidelines differed notably from that of the Centers for Disease Control and Prevention (CDC) by recommending routine environmental testing of the hospital water distribution system even when cases of health care-acquired Legionnaires' disease had never been identified. OBJECTIVES: Our purpose was to (1) evaluate the impact of the ACHD guidelines on the Legionella diagnostic and preventive practices of health care facilities in Allegheny and surrounding counties and (2) compare the incidence of health care-acquired LD before and after issuance of the ACHD guidelines. METHODS: CDC case reports of LD from 1991 to 2001 were tabulated and compiled by the ACHD Infectious Disease Unit and the Association for Professionals in Infection Control and Epidemiology, Inc, Three Rivers Chapter. A survey was distributed to 110 hospitals and long-term care facilities in the region. The results were analyzed as occurring either in the preguideline period (1991-1994) or postguideline period (1995-2001). RESULTS: A significant decrease in the number of health care-acquired cases was demonstrated between the preguideline (33%) and postguideline (9%) periods (P=.0001). In contrast, community-acquired cases increased from 67% pre guideline to 91% post guideline. A total of 71% of the facilities were colonized with Legionella. Disinfection of the water distribution system was initiated by 44% of facilities. Use of urinary antigen testing significantly increased from 40% pre guideline to 79% post guideline (P=.0001). CONCLUSIONS: Health care-acquired LD declined significantly after the issuance of guidelines for prevention and control of health care-acquired LD. The decline was associated with health care facilities performing routine environmental monitoring of their water distribution systems followed by the initiation of disinfection methods if indicated. Two unanticipated benefits were (1) cases of LD in the community and long-term care facilities were uncovered as a result of increased availability of Legionella tests and (2) litigation and unfavorable publicity involving ACHD hospitals ceased.


Surveillance, prevention, and control of legionellosis in a tropical city-state

Goh KT, Ng DL, Yap J, Ma S, Ooi EE.

Am J Infect Control. 2005 Jun;33(5):286-91.

ABSTRACT: Legionellosis is endemic in Singapore, with sporadic cases reported throughout the year. The absence of outbreak could be due to the low prevalence of the highly pathogenic Pontiac subtype of Legionella pneumophila in the urban environment. Mandatory maintenance of cooling towers and water fountains has been put in place, and the effectiveness of legislation in minimizing the occurrence and risk of outbreak of legionellosis is being evaluated.


Prevention and control of health care-associated waterborne infections in health care facilities

Exner M, Kramer A, Lajoie L, Gebel J, Engelhart S, Hartemann P.

Am J Infect Control. 2005 Jun;33(5 Pt 2):S26-40.

ABSTRACT: The current article is a review of the public health risks attributable to waterborne pathogens in health care. The consequences of health care-associated infections (HAIs) are discussed. Not only are Legionella spp involved in HAIs, but also Pseudomonas aeruginosa, other gram-negative microorganisms, fungi, and amoeba-associated bacteria. This is particularly noteworthy among immunocompromised patients. New prevention strategies and control measures brought about through advanced planning, facility remodelling and reconstruction, disinfection, and filtration have resulted in a significant reduction of the incidence of waterborne HAIs. The positive consequences of a comprehensive multibarrier approach including prevention and control programs in health care facilities are discussed. Environmental cultures are now integrated within the infection control program of some European countries. In high-risk areas, the application of disposable sterile point-of-use filters for faucets and shower heads appears to be the practice of choice to efficiently control waterborne pathogens and to prevent infections.


Efficacy of new point-of-use water filter for preventing exposure to Legionella and waterborne bacteria

Sheffer PJ, Stout JE, Wagener MM, Muder RR.

Am J Infect Control. 2005 Jun;33(5 Pt 2):S20-5.

ABSTRACT: Background Legionella species cause health care-acquired infections in which immunocompromised patients are disproportionately affected. Epidemiologic studies have demonstrated that point-of-use water fixtures are the reservoirs for these infections. The current approach to prevention is system-wide chemical disinfection of the hospital water system. These methods affect both low-risk and high-risk areas. A more effective approach to prevention may be a targeted approach aimed at protecting high-risk patients. One option is the application of a physical barrier (filter) at the point-of-use water fixture. Objectives To evaluate the ability of point-of-use filters to eliminate Legionella and other pathogens from water. Methods One hundred twenty-milliliter hot water samples were collected from 7 faucets (4 with filters and 3 without) immediately and after a 1-minute flush. Samples were collected every 2 or 3 days for 1 week. This cycle was repeated for 12 weeks. Samples were cultured for Legionella , total heterotrophic plate count (HPC) bacteria, and Mycobacterium species. Results Five hundred ninety-four samples were collected over 12 cycles. No Legionella or Mycobacterium were isolated from the faucets with filters between T = 0 and T = 8 days. The mean concentration of L pneumophila and Mycobacterium from the control faucets was 104.5 CFU/mL and 0.44 CFU/mL, respectively. The filters achieved a greater than 99% reduction in HPC bacteria in the immediate and postflush samples. Conclusions Point-of-use filters completely eliminated L pneumophila and Mycobacterium from hot water samples. These filter units could prevent exposure of high-risk patients to waterborne pathogens.


The role of the intensive care unit environment in the pathogenesis and prevention of ventilator-associated pneumonia

Crnich CJ, Safdar N, Maki DG.

Dennis G Maki MD, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison WI 53792.

Respir Care. 2005 Jun;50(6):813-38.

ABSTRACT: Ventilator-associated pneumonia is preceded by lower-respiratory-tract colonization by pathogenic microorganisms that derive from endogenous or exogenous sources. Most ventilator-associated pneumonias are the result of exogenous nosocomial colonization, especially, pneumonias caused by resistant bacteria, such as methicillin-resistant Staphylococcus aureus and multi-resistant Acinetobacter baumannii and Pseudomonas aeruginosa, or by Legionella species or filamentous fungi, such as Aspergillus. Exogenous colonization originates from a very wide variety of animate and inanimate sources in the intensive care unit environment. As a result, a strategic approach that combines measures to prevent cross-colonization with those that focus on oral hygiene and prevention of microaspiration of colonized oropharyngeal secretions should bring the greatest reduction in the risk of ventilator-associated pneumonia. This review examines strategies to prevent transmission of environmental pathogens to the vulnerable mechanically-ventilated patient.


The pathogenesis of ventilator-associated pneumonia: its relevance to developing effective strategies for prevention

Safdar N, Crnich CJ, Maki DG.

Dennis G Maki, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison WI 53792.

Respir Care. 2005 Jun;50(6):725-41.

ABSTRACT: Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in the intensive care unit and is associated with major morbidity and attributable mortality. Strategies to prevent VAP are likely to be successful only if based upon a sound understanding of pathogenesis and epidemiology. The major route for acquiring endemic VAP is oropharyngeal colonization by the endogenous flora or by pathogens acquired exogenously from the intensive care unit environment, especially the hands or apparel of health-care workers, contaminated respiratory equipment, hospital water, or air. The stomach represents a potential site of secondary colonization and reservoir of nosocomial Gram-negative bacilli. Endotracheal-tube biofilm formation may play a contributory role in sustaining tracheal colonization and also have an important role in late-onset VAP caused by resistant organisms. Aspiration of microbe-laden oropharyngeal, gastric, or tracheal secretions around the cuffed endotracheal tube into the normally sterile lower respiratory tract results in most cases of endemic VAP. In contrast, epidemic VAP is most often caused by contamination of respiratory therapy equipment, bronchoscopes, medical aerosols, water (eg, Legionella) or air (eg, Aspergillus or the severe acute respiratory syndrome virus). Strategies to eradicate oropharyngeal and/or intestinal microbial colonization, such as with chlorhexidine oral care, prophylactic aerosolization of antimicrobials, selective aerodigestive mucosal antimicrobial decontamination, or the use of sucralfate rather than H(2) antagonists for stress ulcer prophylaxis, and measures to prevent aspiration, such as semirecumbent positioning or continuous subglottic suctioning, have all been shown to reduce the risk of VAP. Measures to prevent epidemic VAP include rigorous disinfection of respiratory equipment and bronchoscopes, and infection-control measures to prevent contamination of medical aerosols. Hospital water should be Legionella-free, and high-risk patients, especially those with prolonged granulocytopenia or organ transplants, should be cared for in hospital units with high-efficiency-particulate-arrestor (HEPA) filtered air. Routine surveillance of VAP, to track endemic VAPs and facilitate early detection of outbreaks, is mandatory.


Reusable terminal tap water filters for nosocomial legionellosis prevention

Vonberg RP, Rotermund-Rauchenberger D, Gastmeier P.

Institut fur Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.

Ann Hematol. 2005 Jun;84(6):403-5.

ABSTRACT: Hospital water supplies often contain Legionella spp. and therefore represent a source of nosocomial infection especially for immunocompromised patients in intensive care or organ transplant units. Therefore, pathogen-free water should be provided for the care of these patients. Approaches of long-term Legionella spp. eradication from the plumbing system are rarely successful. Exposition prophylaxis might be another reasonable approach in high-risk patient care. To investigate the ability to provide water free of Legionella spp. with reusable water filters, a surveillance of splash water samples was performed. After determining the burden of Legionella spp. in the plumbing system of a paediatric oncological ward by ten unfiltered splash water samples, ten designated water taps were provided with terminal tap water filters that could be reprocessed by thermal disinfection. A further 129 samples were taken after a usage interval of 7 days and 10 more samples after a usage interval of 21 days before reprocessing the filters. All samples were checked for growth of Legionella spp. as well as other pathogenic bacteria. A total germ count of all samples was also performed. Half of the unfiltered splash water samples revealed growth of Legionella spp. All filtered water samples remained free of Legionella. Total germ count did not increase before a usage interval of 7 days. We believe the water filters tested are suitable for prevention of nosocomial legionellosis when reprocessed after 7 days as recommended by the manufacturer. To avoid retrograde contamination of filters, education of staff and patients in handling these devices is mandatory.


Use of terminal tap water filter systems for prevention of nosocomial legionellosis

Vonberg RP, Eckmanns T, Bruderek J, Ruden H, Gastmeier P.

Division of Hospital Epidemiology and Infection Control, Institute for Medical Microbiology and Hospital Epidemiology, Medical School Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.

J Hosp Infect. 2005 Jun;60(2):159-62.

ABSTRACT: Hospital water supplies often contain Legionella spp. and represent a potential source of nosocomial infection, especially for immunocompromised patients or those in intensive care units. Therefore, pathogen-free water should be provided for such high-risk patients. Surveillance of splash water was performed in high-risk patient care areas at Berlin Charite-University Medicine (506 samples) and Medical School Hannover (767 samples) to investigate the ability to provide water that was free from Legionella spp. by the use of disposable, terminal tap water filter systems with non-impregnated, as well as impregnated, filters with prolonged usage intervals. Twenty (Berlin) and 32 (Hannover) water outlets were provided with disposable filters with a pore size of 0.2 microm. Testing of unfiltered tap water revealed growth of Legionella spp. in 53 of 210 (Berlin) and 30 of 32 (Hannover) samples. Non-impregnated, terminal, disposable water filters at taps used for high-risk patient care led to water free from Legionella spp. in 154 of 155 (99.4%) samples after three to four days and in 137 of 141 (97.2%) samples after six to seven days. When testing a new impregnated filter, 255 of 256 (99.6%) samples remained free from Legionella spp. after continuous use for seven days, as recommended by the manufacturers, and also after 10 days. Samples that were positive for Legionella spp. contained 1-4 cfu/mL. We believe that an impregnated filter system is suitable for the prevention of nosocomial Legionellosis in high-risk patient care areas.


Surveillance of hospital water and primary prevention of nosocomial legionellosis: what is the evidence?

O'Neill E, Humphreys H.

Department of Clinical Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland.

J Hosp Infect. 2005 Apr;59(4):273-9.

ABSTRACT: Hospital-acquired Legionnaires' disease may be sporadic or may occur as part of an outbreak. As Legionella spp. are ubiquitous in many water systems, it is not surprising that hospital water may be colonized with Legionella pneumophila and other species. However, there is some controversy about the relationship between the presence of legionella in hospital water systems and nosocomial legionellosis. Primary prevention, i.e. measures to prevent legionella in a hospital or healthcare facility with no previous documented cases of nosocomial legionellosis, includes heightened awareness of hospital-acquired Legionnaires' disease with appropriate laboratory diagnostic facilities, and ensuring that the water system is well designed and maintained in accordance with national standards, e.g. the circulating hot water is maintained above 55 degrees C. Secondary prevention, i.e. preventing further cases occurring when a case has been confirmed, should include an investigation to exclude the hospital water system as a source. However, the necessity to sample hospital water routinely to detect legionella outside of outbreaks, i.e. as a component of primary prevention, is unclear. Some studies demonstrate a clear link but others do not. Differences between the patient populations studied, the methods of laboratory diagnosis of clinical cases, the analysis of hospital water and differences in the design of hospital water systems may partly explain this. Whilst further research, probably in the form of multi-centred prospective trials, is needed to confirm the relationship between environmental legionella and hospital-acquired legionellosis, including establishing the relative importance of L. pneumophila group 1 vs. non-group 1 and other Legionella spp., each hospital should consider the spectrum of patients at particular risk locally. Centres with transplant units or other patients with significant immunosuppression should, in the interim, consider routine sampling for legionella in hospital water in addition to other control measures. Therefore, infection control teams must work closely with hospital engineering and technical services departments and hospital management, as well as ensuring that physicians and others have a heightened awareness of hospital-acquired legionellosis.


Risk and management in hospital water systems for Legionella pneumophila: a case study in Rio de Janeiro-Brazil

Ferreira AP.

Oswaldo Cruz Foundation. Sergio Arouca National School of Public Health, Rio de Janeiro , Brazil .

Int J Environ Health Res. 2004 Dec;14(6):453-9.

ABSTRACT: This article analyses the water used at hospitals in Rio de Janeiro , Brazil . The research, based on microbiological and physical-chemical aspects, suggests subsidies for normalization of hospital potable water systems and makes recommendations for standardization of operational procedures for inspection for Legionella pneumophila. A total of 16 hospitals were inspected and positive results for the presence of L. pneumophila were found at five hospitals. These hospitals were integrated in a research project aiming at the detection and quantification of this pathogen. During 10 consecutive weeks, four collections representing a total of 200 analyses were done at the five researched hospitals. In this way seven physical-chemical parameters and three microbiological parameters were observed to evaluate the quality of water in each hospital. The results showed that routine surveillance for a hospital water distribution system is fundamental for public health and must include, as a priority, monitoring of L. pneumophila. The water quality varies in accordance with the hospital water system involved. It is important and necessary to implement environmental culturing in order to minimize hospital infection, in particular, pneumonia data and also to provide the basis for disinfection of the water system.


Guidelines for community-acquired pneumonia: are they reflected in practice?

Flanders SA, Halm EA.

Department of Medicine, University of California, San Francisco, California, USA.

Treat Respir Med. 2004;3(2):67-77.

ABSTRACT: Community-acquired pneumonia (CAP) is common, costly, and clinically serious. Several national and international practice guidelines have been developed to promote more appropriate, cost-effective care for patients with CAP. This article compares and contrasts eight international practice guidelines for the management of CAP, describes the extent to which recommendations are reflected in practice, and proposes explanations for non-adherence to guidelines. We found consistency in recommendations across all the guidelines for the management of patients with CAP requiring intensive care. In this setting, all guidelines recommend chest radiography, sputum Gram stain and culture, blood cultures, testing for Legionella pneumophila, and timely administration of antibiotics active against both typical (i.e. Streptococcus pneumoniae, Hemophilus influenzae) and atypical organisms (i.e. Legionella spp., Mycoplasma pneumoniae, and Chlamydia pneumoniae). Recommendations for the management of the average inpatient with pneumonia were more variable, with the greatest differences between the North American and European guidelines. The North American guidelines (in contrast to European ones), recommended empiric treatment of typical and atypical organisms in all inpatients. There were also differences in policies regarding the necessity of chest radiography, sputum studies, and serologic testing. Some guidelines explicitly embrace the use of prediction rules to inform the decision to hospitalize, while others do not. Some of these admission decision algorithms focus on identifying low risk patients, while others are most concerned with high risk patients. There was also considerable variation in the specificity and operationalization of clinical criteria for switching from parenteral to oral antibiotics or judging appropriateness for discharge. Many recommendations for key management decisions tended to lack explicit, objective, and actionable criteria that could be easily implemented in real world practice. Review of the pneumonia literature revealed that physician performance of guideline-recommended best practices is often suboptimal. Administration of timely antibiotics (< or =8 hours of presentation) and use of first-line antibiotics occurred in 75-85% and 18-79% of cases, respectively. Collection of blood cultures within 24 hours of presentation and prior to administration of antibiotics was achieved in 69-83% and 63-82% of cases, respectively. Screening the eligibility of CAP patients for hospital-based pneumococcal and influenza vaccination occurred on average in 11 and 14% of hospitalizations, respectively, in the US. Lack of awareness of guidelines, conflicting advice among them, and lack of specific, objective, actionable recommendations most likely contribute to nonadherence to CAP guidelines. Increased attention to these factors will be needed if professional society practice guidelines are to fulfill their promise as tools for improving the quality and outcomes of care for patients with pneumonia.


Surveillance data from public spa inspections--United States, May-September 2002

Centers for Disease Control and Prevention (CDC).

MMWR Morb Mortal Wkly Rep. 2004 Jul 2;53(25):553-5.

ABSTRACT: Approximately 5 million public and private hot tubs, whirlpools, and spas are used in the United States. Extensive spa use combined with inadequate maintenance contribute to recreational water illnesses (RWIs) caused by pathogens such as Pseudomonas spp., Legionella spp., and Mycobacterium spp. In the United States, local environmental health inspectors periodically inspect public spas to determine their compliance with local or state health regulations. During inspections for regulatory compliance, data pertaining to spa water chemistry, filtration and recirculation, and management and operations are collected. This report summarizes spa inspection data from six sites in the United States during May 1-September 1, 2002. The findings underscore the utility of these data for public health decision-making and the need for increased training and vigilance by operators to ensure high-quality spa water for use by the public.


Guidelines for preventing health-care-associated pneumonia, 2003: recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee

Tablan OC, Anderson LJ, Besser R, Bridges C, Hajjeh R; CDC and the Healthcare Infection Control Practices Advisory Committee.

Division of Healthcare Quality Promotion, National Center for Infectious Diseases, USA .

MMWR Recomm Rep. 2004 Mar 26;53(RR-3):1-36.

ABSTRACT: This report updates, expands, and replaces the previously published CDC "Guideline for Prevention of Nosocomial Pneumonia". The new guidelines are designed to reduce the incidence of pneumonia and other severe, acute lower respiratory tract infections in acute-care hospitals and in other health-care settings (e.g., ambulatory and long-term care institutions) and other facilities where health care is provided. Among the changes in the recommendations to prevent bacterial pneumonia, especially ventilator-associated pneumonia, are the preferential use of oro-tracheal rather than naso-tracheal tubes in patients who receive mechanically assisted ventilation, the use of noninvasive ventilation to reduce the need for and duration of endotracheal intubation, changing the breathing circuits of ventilators when they malfunction or are visibly contaminated, and (when feasible) the use of an endotracheal tube with a dorsal lumen to allow drainage of respiratory secretions; no recommendations were made about the use of sucralfate, histamine-2 receptor antagonists, or antacids for stress-bleeding prophylaxis. For prevention of health-care--associated Legionnaires disease, the changes include maintaining potable hot water at temperatures not suitable for amplification of Legionella spp., considering routine culturing of water samples from the potable water system of a facility's organ-transplant unit when it is done as part of the facility's comprehensive program to prevent and control health-care--associated Legionnaires disease, and initiating an investigation for the source of Legionella spp. when one definite or one possible case of laboratory-confirmed health-care--associated Legionnaires disease is identified in an inpatient hemopoietic stem-cell transplant (HSCT) recipient or in two or more HSCT recipients who had visited an outpatient HSCT unit during all or part of the 2-10 day period before illness onset. In the section on aspergillosis, the revised recommendations include the use of a room with high-efficiency particulate air filters rather than laminar airflow as the protective environment for allogeneic HSCT recipients and the use of high-efficiency respiratory-protection devices (e.g., N95 respirators) by severely immunocompromised patients when they leave their rooms when dust-generating activities are ongoing in the facility. In the respiratory syncytial virus (RSV) section, the new recommendation is to determine, on a case-by-case basis, whether to administer monoclonal antibody (palivizumab) to certain infants and children aged <24 months who were born prematurely and are at high risk for RSV infection. In the section on influenza, the new recommendations include the addition of oseltamivir (to amantadine and rimantadine) for prophylaxis of all patients without influenza illness and oseltamivir and zanamivir (to amantadine and rimantadine) as treatment for patients who are acutely ill with influenza in a unit where an influenza outbreak is recognized. In addition to the revised recommendations, the guideline contains new sections on pertussis and lower respiratory tract infections caused by adenovirus and human parainfluenza viruses and refers readers to the source of updated information about prevention and control of severe acute respiratory syndrome.


Guidelines for community-acquired pneumonia in the ICU

Wilkinson M, Woodhead MA.

Manchester Royal Infirmary, Manchester, UK.

Curr Opin Crit Care. 2004 Feb;10(1):59-64.

ABSTRACT: Community-acquired pneumonia remains a common and serious condition worldwide. Severe community-acquired pneumonia requiring ICU admission is a distinct entity with different pathogens, outcomes, and management. The mortality rate in severe community-acquired pneumonia can be more than 50%. Over the past decade, some international guidelines for the management of community-acquired pneumonia have been developed in an attempt to optimize patient care. These guidelines have developed prediction tools to direct clinicians in the management of community-acquired pneumonia, including when to admit a patient to the ICU and selecting appropriate investigations and antimicrobial therapy. The individual recommendations of these guidelines and the guidelines as a whole require further studies.  


European Guidelines for Control and Prevention of Travel Associated Legionnaires' Disease: the Italian experience

Rota MC, Caporali MG, Massari M.

Laboratorio di Epidemiologia e Biostatistica, Istituto Superiore di Sanita, Rome, Italy.

Euro Surveill. 2004 Feb;9(2):10-1.

ABSTRACT: In Italy, 35 clusters of travel associated Legionnaires' disease were identified from July 2002, when the European Guidelines for Control and Prevention of Travel Associated Legionnaires' Disease have been adopted by the EWGLINET network, to October 2003. Eight per cent (28.6%) would not have been identified without the network. The clusters detected were small, ranging from 2 cases to a maximum of 6. All clusters involved 5 camping sites and 30 hotels/residences, and an overall of 87 patients. The diagnosis was confirmed in 92.0% of the cases and mainly performed by urinary antigen detection (84.7%). A clinical isolate was available only in one case. Following environmental investigations, samples were collected for all the 35 clusters from the water system, and Legionella pneumophila was found in 23 occasions (65.7%). In 15 resorts out of 35, investigations were already in progress at the time of EWGLI cluster notification, since in Italy full environmental investigation is performed even after notification of a single case. Control measures were implemented in all accommodation sites at risk and one hotel only was closed. In all the 35 clusters, reports were completed and sent on time, highlighting that it is possible to comply with the procedures requested by the European Guidelines.

Update of practice guidelines for the management of community-acquired pneumonia in immunocompetent adults

Mandell LA, Bartlett JG, Dowell SF, File TM Jr, Musher DM, Whitney C; Infectious Diseases Society of America.

McMaster University, Hamilton, Ontario, Canada.

Clin Infect Dis. 2003 Dec 1;37(11):1405-33.



Guidelines for environmental infection control in health-care facilities. Recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC)

Sehulster L, Chinn RY; CDC; HICPAC.

Division of Healthcare Quality Promotion, National Center for Infectious Diseases.

MMWR Recomm Rep. 2003 Jun 6;52(RR-10):1-42.

ABSTRACT: The health-care facility environment is rarely implicated in disease transmission, except among patients who are immunocompromised. Nonetheless, inadvertent exposures to environmental pathogens (e.g., Aspergillus spp. and Legionella spp.) or airborne pathogens (e.g., Mycobacterium tuberculosis and varicella-zoster virus) can result in adverse patient outcomes and cause illness among health-care workers. Environmental infection-control strategies and engineering controls can effectively prevent these infections. The incidence of health-care--associated infections and pseudo-outbreaks can be minimized by 1) appropriate use of cleaners and disinfectants; 2) appropriate maintenance of medical equipment (e.g., automated endoscope reprocessors or hydrotherapy equipment); 3) adherence to water-quality standards for hemodialysis, and to ventilation standards for specialized care environments (e.g., airborne infection isolation rooms, protective environments, or operating rooms); and 4) prompt management of water intrusion into the facility. Routine environmental sampling is not usually advised, except for water quality determinations in hemodialysis settings and other situations where sampling is directed by epidemiologic principles, and results can be applied directly to infection-control decisions. This report reviews previous guidelines and strategies for preventing environment-associated infections in health-care facilities and offers recommendations. These include 1) evidence-based recommendations supported by studies; 2) requirements of federal agencies (e.g., Food and Drug Administration, U.S. Environmental Protection Agency, U.S. Department of Labor, Occupational Safety and Health Administration, and U.S. Department of Justice); 3) guidelines and standards from building and equipment professional organizations (e.g., American Institute of Architects, Association for the Advancement of Medical Instrumentation, and American Society of Heating, Refrigeration, and Air-Conditioning Engineers); 4) recommendations derived from scientific theory or rationale; and 5) experienced opinions based upon infection-control and engineering practices. The report also suggests a series of performance measurements as a means to evaluate infection-control efforts.


Prevenzione della legionellosi: confronto tra linee guida europee ed extraeuropee

Ditommaso S, Biasin C, Giacomuzzi M, Zotti CM, Ruggenini A, Moiraghi A

Dip. Sanità Pubblica e Microbiologia, Università degli Studi di Torino, Torino.

Giornale Italiano delle Infezioni Ospedaliere vol.10, n.1, Gennaio-Marzo 2003, pag 7-24.

RIASSUNTO: Negli ultimi anni, a seguito del verificarsi di numerosi casi di legionellosi, molti paesi hanno emanato raccomandazioni e linee guida in relazione al problema. Obiettivo di questo lavoro è stato quello di mettere in evidenza concordanze e divergenze su temi fondamentali quali: rischio di contrarre l’infezione, opportunità di controlli ambientali e di bonifiche, rischio professionale. Le divergenze riscontrate sono numerose, tuttavia l’argomento è in continua evoluzione. Soltanto la sperimentazione sul campo della sorveglianza  e del controllo potrà consentire di acquisire comportamenti validati, e di adottare misure di intervento efficaci e fattibili, superando la disomogeneità delle indicazioni presenti nelle documentazioni esistenti.