Adherence to Legionella control regulations and guidelines in Norwegian nursing homes: a cross-sectional survey.

BACKGROUND: Infection by Legionella bacteria is a risk to elderly individuals in health care facilities and should be managed by preventing bacterial proliferation in internal water systems. Norwegian legislation calls for a mandatory Legionella-specific risk assessment with the subsequent introduction of an adapted water management programme. The present study investigates adherence to legislation and guidelines on Legionella control and prevention in Norwegian nursing homes. METHODS: A cross-sectional survey was distributed to Norwegian municipalities to investigate the status of Legionella specific risk assessments of internal water distribution systems and the introduction of water management programmes in nursing homes. RESULTS: A total of 55.1% (n = 228) of the participating nursing homes had performed Legionella-specific risk assessments, of which 55.3% (n = 126) stated that they had updated the risk assessment within the last year. 96.5% introduced a water management programme following a risk assessment, whereas 59.6% of the ones without a risk assessment did the same. Nursing homes with risk assessments were more likely to monitor Legionella levels than those without (61.2% vs 38.8%), to remove dead legs (44.7% vs 16.5%), and to select biocidal preventive treatment over hot water flushing (35.5% vs 4.6%). CONCLUSIONS: This study presents novel insight into Legionella control in Norway, suggesting that adherence to mandatory risk assessment in nursing homes is moderate-low. Once performed, the risk assessment seems to be advantageous as an introduction to future Legionella prevention in terms of the scope and contents of the water management programme.

Environmental Investigation and Surveillance for Legionella in Aotearoa New Zealand, 2000-2020.

The reported rate of legionellosis is increasing in Aotearoa New Zealand (NZ) with most cases community-acquired, sporadic (non-outbreak) and without an identifiable source. This analysis used two datasets to describe the environmental sources that contribute to Legionella in NZ, based on linkages with outbreaks and sporadic clinical cases, and analysis of environmental testing data. These findings highlight the need for enhanced environmental investigation of clinical cases and outbreaks. There is also a need for systematic surveillance testing of high-risk source environments to support more rigorous controls to prevent legionellosis.

Impact of Chlorine and Chloramine on the Detection and Quantification of Legionella pneumophila and Mycobacterium Species.

Potable water can be a source of transmission for legionellosis and nontuberculous mycobacterium (NTM) infections and diseases. Legionellosis is caused largely by Legionella pneumophila, specifically serogroup 1 (Sg1). Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium abscessus are three leading species associated with pulmonary NTM disease. The estimated rates of these diseases are increasing in the United States, and the cost of treatment is high. Therefore, a national assessment of water disinfection efficacy for these pathogens was needed. The disinfectant type and total chlorine residual (TClR) were investigated to understand their influence on the detection and concentrations of the five pathogens in potable water. Samples (n = 358) were collected from point-of-use taps (cold or hot) from locations across the United States served by public water utilities that disinfected with chlorine or chloramine. The bacteria were detected and quantified using specific primer and probe quantitative-PCR (qPCR) methods. The total chlorine residual was measured spectrophotometrically. Chlorine was the more potent disinfectant for controlling the three mycobacterial species. Chloramine was effective at controlling L. pneumophila and Sg1. Plotting the TClR associated with positive microbial detection showed that an upward TClR adjustment could reduce the bacterial count in chlorinated water but was not as effective for chloramine. Each species of bacteria responded differently to the disinfection type, concentration, and temperature. There was no unifying condition among the water characteristics studied that achieved microbial control for all. This information will help guide disinfectant decisions aimed at reducing occurrences of these pathogens at consumer taps and as related to the disinfectant type and TClR.IMPORTANCE The primary purpose of tap water disinfection is to control the presence of microbes. This study evaluated the role of disinfectant choice on the presence at the tap of L. pneumophila, its Sg1 serogroup, and three species of mycobacteria in tap water samples collected at points of human exposure at locations across the United States. The study demonstrates that microbial survival varies based on the microbial species, disinfectant, and TClR.

Preventing legionellosis outbreaks by a quick detection of airborne Legionella pneumophila.

Legionellosis is a severe pneumonic infection caused by inhaling bacteria of the genus Legionella. Most cases reported in the USA and Europe are associated with the species Legionella pneumophila. This Gram-negative bacterium can survive within a wide spectrum of temperatures, and be transmitted via aerosols from multiple aquatic sources: fountains, thermal spas and other water systems. Although the PCR is one of the most popular methods to verify its presence in environmental or clinical samples, the direct application of this technique to ambient air samples is unusual because of the scarce material in the specimens. Here, we have developed a two-PCR assay, carried out over the V3 and V5 hypervariable regions of the 16S rRNA gene, to detect specifically the pathogenic bacteria Legionella pneumophila in outdoor air samples with low concentration of DNA. The application of this protocol does not require culture and retrieves quick results to activate the corresponding public alerts to prevent legionellosis outbreaks.

Legionellosis in health care facilities: state of the art in control and prevention in Italy.

BACKGROUND: Nosocomial water systems may be contaminated by Legionella spp; therefore, health care facilities represent a potential health risk for patients and health care staff. Active, well-planned clinical and environmental surveillance in hospitals is the most important instrument of prevention. AIMS AND METHODS: The aim of the present article was to outline the state of the art in legionellosis control and prevention among Italian health care facilities by reporting some experiences in the field. RESULTS: Our results showed that Legionella spp. are largely reported as both hospital water system contaminants and etiological agents in water-related health care-associated infections (HCAI) in Italy. Among the numerous sources of HCAI, water is the most investigated, although it has been demonstrated that air sampling may provide additional information for risk assessment. CONCLUSIONS: More appropriate risk assessment is needed, especially in large facilities. In addition, more sensitive diagnostic tests should be used and dedicated training courses should be implemented in health care facilities.

Legionella: a reemerging pathogen.

PURPOSE OF REVIEW: The present review summarizes new knowledge about Legionella epidemiology, clinical characteristics, community-associated and hospital-based outbreaks, molecular typing and molecular epidemiology, prevention, and detection in environmental and clinical specimens. RECENT FINDINGS: The incidence of Legionnaire's disease is rising and the mortality rate remains high, particularly for immunocompromised patients. Extracorporeal membrane oxygenation may help support patients with severe respiratory failure. Fluoroquinolones and macrolides appear to be equally efficacious for treating Legionnaires' disease. Whole genome sequencing is an important tool for determining the source for Legionella infections and for understanding routes of transmission and mechanisms by which new pathogenic clones emerge. Real-time quantitative polymerase chain reaction testing of respiratory specimens may improve our ability to diagnose Legionnaire's disease. The frequency of viable but nonculturable organisms is quite high in some water systems but their role in causing clinical disease has not been defined. SUMMARY: Legionellosis remains an important public health threat. To prevent these infections, staff of municipalities and large buildings must implement effective water system management programs that reduce Legionella growth and transmission and all Medicare-certified healthcare facilities must have water management policies. In addition, we need better methods for detecting Legionella in water systems and in clinical specimens to improve prevention strategies and clinical diagnosis.

Atypical pathogens in hospitalized patients with community-acquired pneumonia: a worldwide perspective.

BACKGROUND: Empirical antibiotic coverage for atypical pathogens in community-acquired pneumonia (CAP) has long been debated, mainly because of a lack of epidemiological data. We aimed to assess both testing for atypical pathogens and their prevalence in hospitalized patients with CAP worldwide, especially in relation with disease severity. METHODS: A secondary analysis of the GLIMP database, an international, multicentre, point-prevalence study of adult patients admitted for CAP in 222 hospitals across 6 continents in 2015, was performed. The study evaluated frequency of testing for atypical pathogens, including L. pneumophila, M. pneumoniae, C. pneumoniae, and their prevalence. Risk factors for testing and prevalence for atypical pathogens were assessed through univariate analysis. RESULTS: Among 3702 CAP patients 1250 (33.8%) underwent at least one test for atypical pathogens. Testing varies greatly among countries and its frequency was higher in Europe than elsewhere (46.0% vs. 12.7%, respectively, p < 0.0001). Detection of L. pneumophila urinary antigen was the most common test performed worldwide (32.0%). Patients with severe CAP were less likely to be tested for both atypical pathogens considered together (30.5% vs. 35.0%, p = 0.009) and specifically for legionellosis (28.3% vs. 33.5%, p = 0.003) than the rest of the population. Similarly, L. pneumophila testing was lower in ICU patients. At least one atypical pathogen was isolated in 62 patients (4.7%), including M. pneumoniae (26/251 patients, 10.3%), L. pneumophila (30/1186 patients, 2.5%), and C. pneumoniae (8/228 patients, 3.5%). Patients with CAP due to atypical pathogens were significantly younger, showed less cardiovascular, renal, and metabolic comorbidities in comparison to adult patients hospitalized due to non-atypical pathogen CAP. CONCLUSIONS: Testing for atypical pathogens in patients admitted for CAP in poorly standardized in real life and does not mirror atypical prevalence in different settings. Further evidence on the impact of atypical pathogens, expecially in the low-income countries, is needed to guidelines implementation.

Control and prevention measures for legionellosis in hospitals: A cross-sectional survey in Italy.

Risk assessment, environmental monitoring, and the disinfection of water systems are the key elements in preventing legionellosis risk. The Italian Study Group of Hospital Hygiene of the Italian Society of Hygiene, Preventive Medicine, and Public Health and the Italian Multidisciplinary Society for the Prevention of Health Care-Associated Infections carried out a national cross-sectional survey to investigate the measures taken to prevent and control legionellosis in Italian hospitals. A multiple-choice questionnaire was developed, comprising 71 questions regarding hospital location, general characteristics, clinical and environmental surveillance, and control and preventive measures for legionellosis in 2015. Overall, 739 hospitals were enrolled from February to June 2017, and 178 anonymous questionnaires were correctly completed and evaluated (response rate: 24.1%). The survey was conducted using the SurveyMonkey® platform, and the data were analyzed using Stata 12 software. Of the participating hospitals, 63.2% reported at least one case of legionellosis, of which 28.2% were of proven nosocomial origin. The highest case numbers were reported in the Northern Italy, in hospitals with a pavilion structure or cooling towers, and in hospitals with higher numbers of beds, wards and operating theaters. Laboratory diagnosis was performed using urinary antigen testing alone (31.9%), both urinary antigen testing and single antibody titer (17.8%), or with seroconversion also added (21.5%). Culture-based or molecular investigations were performed in 28.8% and 22.1% of the clinical specimens, respectively. The water systems were routinely tested for Legionella in 97.4% of the hospitals, 62% of which detected a positive result (> 1000 cfu/L). Legionella pneumophila serogroup 2-15 was the most frequently isolated species (58.4%). The most common control measures were the disinfection of the water system (73.7%), mostly through thermal shock (37.4%) and chlorine dioxide (34.4%), and the replacement (69.7%) or cleaning (70.4%) of faucets and showerheads. A dedicated multidisciplinary team was present in 52.8% of the hospitals, and 73% of the hospitals performed risk assessment. Targeted training courses were organized in 36.5% of the hospitals, involving nurses (30.7%), physicians (28.8%), biologists (21.5%), technicians (26.4%), and cleaners (11%). Control and prevention measures for legionellosis are present in Italian hospitals, but some critical aspects should be improved. More appropriate risk assessment is necessary, especially in large facilities with a high number of hospitalizations. Moreover, more sensitive diagnostic tests should be used, and dedicated training courses should be implemented.

Environmental surveillance of Legionella pneumophila in distal water supplies of a hospital for early identification & prevention of hospital-acquired legionellosis.

Background & objectives: Legionella pneumophila, a ubiquitous aquatic organism is found to be associated with the development of the community as well as hospital-acquired pneumonia. Diagnosing Legionella infection is difficult unless supplemented with, diagnostic laboratory testing and established evidence for its presence in the hospital environment. Hence, the present study was undertaken to screen the hospital water supplies for the presence of L. pneumophila to show its presence in the hospital environment further facilitating early diagnosis and prevention of hospital-acquired legionellosis. Methods: Water samples and swabs from the inner side of the same water taps were collected from 30 distal water outlets present in patient care areas of a tertiary care hospital. The filtrate obtained from water samples as well as swabs were inoculated directly and after acid buffer treatment on plain and selective (with polymyxin B, cycloheximide and vancomycin) buffered charcoal yeast extract medium. The colonies grown were identified using standard methods and confirmed for L. pneumophila by latex agglutination test. Results: About 6.66 per cent (2/30) distal water outlets sampled were found to be contaminated with L. pneumophila serotype 2-15. Isolation was better with swabs compared to water samples. Interpretation & conclusions: The study showed the presence of L. pneumophila colonization of hospital water outlets at low levels. Periodic water sampling and active clinical surveillance in positive areas may be done to substantiate the evidence, to confirm or reject its role as a potential nosocomial pathogen in hospital environment.

Incorporating Time-Dose-Response into Legionella Outbreak Models.

A novel method was used to incorporate in vivo host-pathogen dynamics into a new robust outbreak model for legionellosis. Dose-response and time-dose-response (TDR) models were generated for Legionella longbeachae exposure to mice via the intratracheal route using a maximum likelihood estimation approach. The best-fit TDR model was then incorporated into two L. pneumophila outbreak models: an outbreak that occurred at a spa in Japan, and one that occurred in a Melbourne aquarium. The best-fit TDR from the murine dosing study was the beta-Poisson with exponential-reciprocal dependency model, which had a minimized deviance of 32.9. This model was tested against other incubation distributions in the Japan outbreak, and performed consistently well, with reported deviances ranging from 32 to 35. In the case of the Melbourne outbreak, the exponential model with exponential dependency was tested against non-time-dependent distributions to explore the performance of the time-dependent model with the lowest number of parameters. This model reported low minimized deviances around 8 for the Weibull, gamma, and lognormal exposure distribution cases. This work shows that the incorporation of a time factor into outbreak distributions provides models with acceptable fits that can provide insight into the in vivo dynamics of the host-pathogen system.

[Evaluation of chlorine dioxide concentrations needed to effectively control contamination by Legionella spp in hospital hot water distribution systems]. / La determinazione della concentrazione efficace di biossido di cloro (ClO2) per il controllo della contaminazione da Legionella spp nei circuiti dell'acqua calda sanitaria.

This aim of the study was to identify effective levels of ClO2 for control of Legionella spp. contamination in the hot water (45-55 °C.) distribution system of a 579-bed hospital in Ravenna (Italy). Overall, 663 hot water samples were collected from the hospital's sinks and shower taps and were analyzed. Trend line analysis, which describes the trend in the number of positive samples collected according to disinfectant concentration, shows that the lowest number of positive samples was achieved with concentrations of ClO2 between 0.22 and 0, 32 mg /l.

Legionellosis on the Rise: A Review of Guidelines for Prevention in the United States.

CONTEXT: Reported cases of legionellosis more than tripled between 2001 and 2012 in the United States. The disease results primarily from exposure to aerosolized water contaminated with Legionella. OBJECTIVE: To identify and describe policies and guidelines for the primary prevention of legionellosis in the US. DESIGN: An Internet search for Legionella prevention guidelines in the United States at the federal and state levels was conducted from March to June 2012. Local government agency guidelines and guidelines from professional organizations that were identified in the initial search were also included. SETTING: Federal, state, and local governing bodies and professional organizations. RESULTS: Guidelines and regulations for the primary prevention of legionellosis (ie, Legionnaires' disease and Pontiac fever) have been developed by various public health and other government agencies at the federal, state, and local levels as well as by professional organizations. These guidelines are similar in recommending maintenance of building water systems; federal and other guidelines differ in the population/institutions targeted, the extent of technical detail, and support of monitoring water systems for levels of Legionella contamination. CONCLUSIONS: Legionellosis deserves a higher public health priority for research and policy development. Guidance across public health agencies for the primary prevention of legionellosis requires strengthening as this disease escalates in importance as a cause of severe morbidity and mortality. We recommend a formal and comprehensive review of national public health guidelines for prevention of legionellosis.

[Legionella spp. contamination in indoor air: preliminary results of an Italian multicenter study]. / La contaminazione indoor da Legionella spp: risultati preliminari di una indagine multicentrica italiana.

OBJECTIVE: To propose a standardized protocol for the evaluation of Legionella contamination in air. DESIGN: A bathroom having a Legionella contamination in water >1,000 cfu/l was selected in 10 different healthcare facilities. Air contamination was assessed by active (Surface Air System, SAS) and passive (Index of Microbial Air, IMA) sampling for 8 hours, about 1 m away from the floor and 50 cm from the tap water. Two hundred liters of air were sampled by SAS every 12 min, after flushing water for 2 min. The IMA value was calculated as the mean value of colony forming units/16 plates exposed during sampling (2 plates/hour). Water contamination was evaluated at T0, after 4 and 8 hours, according to the standard methods. RESULTS: Air contamination by Legionella was found in three healthcare facilities (one with active and two with passive sampling), showing a concomitant tap water contamination (median=40,000; range 1,100-43,000 cfu/l). The remaining seven hospitals isolated Legionella spp. exclusively from water samples (median=8,000; range 1,200-70,000 cfu/l). CONCLUSIONS: Our data suggest that environmental Legionella contamination cannot be assessed only through the air sampling, even in the presence of an important water contamination.

Prevention of legionella infections from toilet flushing cisterns.

INTRODUCTION: Immunocompromised patients are at an increased risk of severe legionella infections. We present the results of an outbreak investigation initiated following a fatal case of hospital-acquired legionellosis linked to contaminated water from a toilet-flushing cistern. Additionally, we provide experimental data on the growth of Legionella spp. in flushing cisterns and propose a straightforward protocol for prevention. METHODS: We monitored the growth of Legionella spp. in the building's hot- and cold-water systems using quantitative bacterial culture on selective agar. Molecular typing of Legionella pneumophila isolates from the infected patient and the water system was conducted through core-genome multi-locus sequence typing (cgMLST). RESULTS: Legionella contamination in the hospital building's cold-water system was significantly higher than in the hot-water system and significantly higher in toilet flushing cistern's water compared with cold water from bathroom sinks and showers. Isolates from the patient and from the flushing cistern of the patient's bathroom were identical by cgMLST. In an experimental setting, daily toilet flushing for a period of 21 days resulted in a 67% reduction in the growth of Legionella spp. in the water of toilet flushing cisterns. Moreover, a one-time disinfection of cisterns with peracetic acid, followed by daily flushing, decreased legionella growth to less than 1% over a period of at least seven weeks in these setting. CONCLUSIONS: One-time disinfection of highly contaminated cisterns with peracetic acid and daily toilet flushing as short-term measure can significantly reduce legionella contamination in flushing cisterns. These measures may aid in preventing legionella infection among immunocompromised patients.

Prevalence of Legionella strains in cooling towers and legionellosis cases in New Zealand.

Over 3,900 water samples from 688 cooling towers were tested for Legionella in 2008 in New Zealand. Of 80 (2.05% isolation rate) Legionella isolates, 10 (12.5%) were L. pneumophila serogroup 1; 10 (12.5%) were L. anisa; nine (11.2%) were L. pneumophila serogroup 8; and one (1.2%) was L. longbeachae serogroup 2. Forty-one (51.2%) Legionella isolates were L. pneumophila serogroups. Over 3,990 water samples from 606 cooling towers were tested for Legionella in 2009 in New Zealand. Of 51 (1.28% isolation rate) Legionella isolates, 18 (35.3%) were L. pneumophila serogroup 1, and 39 (76.4%) were other L. pneumophila serogroups. L. pneumophila serogroups were significantly associated with legionellosis cases in 2008 and 2009. L. longbeachae serogroups were equally significantly associated with legionellosis cases. This significant association of L. longbeachae with legionellosis particularly of L. longbeachae serogroup 1 is unique in that part of the world. The authors' study also showed that the aqueous environment of the cooling tower is not a natural habitat for pathogenic L. longbeachae. Regular monitoring and maintenance of cooling towers have prevented outbreaks of legionellosis.

Legionella pneumophila in Norwegian naval vessels.

BACKGROUND: Little is known about the occurrence of Legionella pneumophila in water supply systems on board ships. Our aim was to study the occurrence of L. pneumophila in the water supply system on board Norwegian naval vessels as the basis for framing preventive strategies against Legionella infection. MATERIAL AND METHOD: Water samples were collected from technical installations and from the water distribution network on board 41 vessels and from ten water filling (bunkering) stations, the sampling taking place in two rounds separated by a one-year interval. The samples were subjected to analysis, including serotyping and genotyping, with a view to identifying the presence of L. pneumophila and of free-living amoebae. RESULTS: L. pneumophila was found in 20 out of a total of 41 vessels in the first round of sampling, and live L. pneumophila serogroup 1 was isolated in seven of the 20 vessels. Free-living amoebae were found in the water supply system in most of the vessels, including all the vessels with L. pneumophila. The same genotype of L. pneumophila was identified in the water in bunkering stations and in the water on board the vessels. INTERPRETATION: L. pneumophila was not present in all the vessels, but all the vessels where the bacterium was found were also contaminated with free-living amoebae. We have demonstrated the probability of the fresh water from bunkering stations being the source of the contamination. In framing preventive strategies, importance should therefore be attached to identifying the source of contamination and the presence of free-living amoebae, as a premise for the establishment and growth of L. pneumophila in onboard water supply systems.

Environmental surveillance and molecular investigation of Legionella spp. in Apulia, in the years 2008-2011.

Legionella spp. is considered an emerging microorganism involved in aquatic environments contamination and cause of Legionnaires' disease. The aims of the study are to evaluate the level of contamination of Legionella spp. in the water system of the largest Hospital of Apulia region during a 4-year surveillance and to establish, by molecular method, the presence of a predominant genotype of L. pn. sg 1. The results showed that Legionella spp. was present in 36% of water samples with Legionella pneumophila serogroup 1 (L. pn. sg 1) the most prevalent species and serogroup and the wards most contaminated are the high risk units. In addition, despite four main clones of L. pn. sg 1 were identified, a predominant genotype existed. In conclusion the study demonstrates the necessity for periodic evaluation on hospitals water system to assess the potential contamination of Legionella spp., performing decontamination in the presence of bacterial contamination, even low, in particular in high risk wards. Moreover, the switching of the disinfection methods may be suggested in order to prevent resistance phenomenon by some L. pn. sg 1 clones.

[The hazards of hospitals and selected public buildings of Legionella pneumophila]. / Zagrozenia szpitali oraz wybranych obiektów uzytecznosci publicznej bakteriami Legionella pneumophila.

UNLABELLED: The registered infection and outbreaks of epidemic tend to monitor potential reservoirs of Legionella infection. According to the Act of 29 March 2007 on the requirements for the quality of water intended for human consumption are required to test for the presence and number of Legionella in the water system of hospitals. In case of detection of L. pneumophila serogroup 1 (SG 1) or increased above normal number other serogroups of bacteria it is necessary to eradicate these bacteria from the water system. The aim of this study was to assess the degree of contamination of the water supply system of selected public buildings and analyze the effectiveness of disinfection methods for the elimination of L. pneumophila in hot water systems. MATERIAL AND METHODS: The materials for this study were hot and cold water samples which were collected from the water supply system of 23 different objects. Enumeration of Legionella bacteria in water samples was determined by membrane filtration (FM) and/or by surface inoculation methods according to the standards: PN-ISO 11731: 2002: "The quality of the water. Detection and enumeration of Legionella" and PN-EN ISO 11731-2: 2008: "Water quality--Detection and enumeration of Legionella--Part 2: Methodology of membrane filtration for water with a small number of bacteria". RESULTS: L. pneumophila was present in 164 samples of hot water, which accounted for 76.99%. In all tested water samples L. pneumophila SG 2-14 strains were detected. The most virulent strain--L. pneumophila SG 1 was not detected. In examined 23 objects in 12 of L. pneumophila exceed acceptable levels > 100 CFU/100 ml. CONCLUSIONS: The presence of L. pneumophila SG 2-14 demonstrated in all examined objects, indicating the risk of infection, and the need for permanent monitoring of the water system supply. The thermal disinfection is the most common, inexpensive, and effective method of control of L. pneumophila used in examined objects, but does not eliminate bacterial biofilm. Disinfection using the filters stopped of L. pneumophila, and was the method of complementary thermal disinfection. Chlorine dioxide is a very effective biocide for large numbers of L. pneumophila in water systems.

Water quality influences Legionella pneumophila determination.

Legionellosis is a respiratory disease of public health concern. The bacterium Legionella pneumophila is the etiologic agent responsible for >90% of legionellosis cases in the United States. Legionellosis transmission primarily occurs through the inhalation or aspiration of contaminated water aerosols or droplets. Therefore, a thorough understanding of L. pneumophila detection methods and their performance in various water quality conditions is needed to develop preventive measures. Two hundred and nine potable water samples were collected from taps in buildings across the United States. L. pneumophila was determined using three culture methods: Buffered Charcoal Yeast Extract (BCYE) culture with Matrix-assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS) identification, Legiolert® 10- and 100-mL tests, and one molecular method: quantitative Polymerase Chain Reaction (qPCR) assay. Culture and molecular positive results were confirmed by secondary testing including MALDI-MS. Eight water quality variables were studied, including source water type, secondary disinfectant, total chlorine residual, heterotrophic bacteria, total organic carbon (TOC), pH, water hardness, cold- and hot-water lines. The eight water quality variables were segmented into 28 categories, based on scale and ranges, and method performance was evaluated in each of these categories. Additionally, a Legionella genus qPCR assay was used to determine the water quality variables that promote or hinder Legionella spp. occurrence. L. pneumophila detection frequency ranged from 2 to 22% across the methods tested. Method performance parameters of sensitivity, specificity, positive and negative predictive values, and accuracy were >94% for the qPCR method but ranged from 9 to 100% for the culture methods. Water quality influenced L. pneumophila determination by culture and qPCR methods. L. pneumophila qPCR detection frequencies positively correlated with TOC and heterotrophic bacterial counts. The source water-disinfectant combination influenced the proportion of Legionella spp. that is L. pneumophila. Water quality influences L. pneumophila determination. To accurately detect L. pneumophila, method selection should consider the water quality in addition to the purpose of testing (general environmental monitoring versus disease-associated investigations).

[Copper and copper alloys. Technology updates]. / Rame e leghe di rame. Aggiornamenti tecnologici.

The correlations between copper and copper alloys and human health have been the subject of some recent and extensive scientific researches. The voluntary risks evaluation, which anticipated the EU REACH Directive application, has shown that copper is a "safe" product for human health and for environment. In addition, it could be of great help thanks to its antibacterial properties. Copper tube can contribute in a relevant way to the prevention of water systems pollution by Legionella. Also the spreading of nosocomial infections is significantly contrasted by the use of copper and copper alloys for the production of articles intended for being frequently touched by people. The Environmental Protection Agency of the United States has in fact "registered" as antibacterial over 350 of copper alloys.