Prevention Of Legionellosis Research Articles

Risk analysis and management of the internal water supply system - changes in the approach to legionellosis prevention in inpatient healthcare facilities

Risk analysis and management of the internal water supply system - changes in the approach to legionellosis prevention in inpatient healthcare facilities

Legionella pneumophila Risk from Air–Water Cooling Units Regarding Pipe Material and Type of Water

Legionellosis is a respiratory disease related to environmental health. There have been manifold studies of pipe materials, risk installations and legionellosis without considering the type of transferred water. The objective of this study was to determine the potential development of the causative agent Legionella pneumophila regarding air-water cooling units, legislative compliance, pipe material and type of water. Forty-four hotel units in Andalusia (Spain) were analysed with respect to compliance with Spanish health legislation for the prevention of legionellosis. The chi-square test was used to explain the relationship between material-water and legislative compliance, and a biplot of the first two factors was generated. Multiple correspondence analysis (MCA) was performed on the type of equipment, legislative compliance, pipe material and type of water, and graphs of cases were constructed by adding confidence ellipses by categories of the variables. Pipe material-type of water (p value = 0.29; p < 0.05) and legislative compliance were not associated (p value = 0.15; p < 0.05). Iron, stainless steel, and recycled and well water contributed the most to the biplot. MCA showed a global pattern in which lead, iron and polyethylene were well represented. Confidence ellipses around categories indicated significant differences among categories. Compliance with Spanish health legislation regarding the prevention and control of legionellosis linked to pipe material and type of water was not observed.

Low Efficacy of Periodical Thermal Shock for Long-Term Control of Legionella spp. in Hot Water System of Hotels.

Different guidelines and regulations for the prevention of legionellosis in public facilities include the recommendation of a periodical thermal shock in the hot water system. The purpose of this study was to assess the efficacy of periodical thermal shocks along a 1-year period on the presence of Legionella spp. in the domestic hot water system of hotels. The Legionella testing results from the period January–December 2019 coming from a group of 77 hotel facilities in the Balearic Islands (Spain) conducting periodical thermal shocks were analyzed. A second group of 44 hotels operating without periodical thermal shocks was used for a comparative analysis. In the facilities where the periodical thermal shock was performed, 16.0% of the results (429 hot water samples collected) were positive for Legionella spp., compared to 21.1% (298 samples), where periodical thermal shock was not performed. Overall, in the thermal shock group, 32.5% of the sites presented at least 1 positive sample along the period of study versus 45.5% in the control group. None of these differences was statistically significant (p-value > 0.05). These findings suggest that the efficacy of regular thermal shock for long-term control of Legionella spp. in domestic hot water systems of hotels is low.

Legionella feeleii: Ubiquitous Pathogen in the Environment and Causative Agent of Pneumonia

L. feeleii is one of the most frequent Legionella species isolated from natural pools of the central region of Spain. This study aimed to evaluate its ecology and to identify this Legionella species as a respiratory pathogen. A PCR assay for detecting the L. feeleii mip gene was developed to identify it in clinical and environmental samples. Culture and PCR were performed in environmental samples from four drinking water treatment plants (DWTPs). Free L. feeleii was only detected in raw water samples (3.4%), while L. feeleii as an Acanthamoeba endosymbiont was found in 30.7% of raw water, 11.5% of decanter biofilm, and 32% of finished water samples. Therefore, Acanthamoeba spp. plays an essential role in the multiplication, persistence, and spread of Legionella species in the environment. The first case of Legionnaires’ disease caused by L. feeleii in Spain is described in this study. The case was diagnosed in an older woman through PCR and sequencing from urine and sputum samples. A respiratory infection could be linked with health care procedures, and the patient presented several risk factors (age, insulin-dependent diabetes, and heart disease). The detection of non-L. pneumophila, such as L. feeleii, is a factor that must be considered when establishing or reviewing measures for the control and prevention of legionellosis.

The contamination of hospital water supply systems by &lt;i&gt;Legionella pneumophila&lt;/i&gt;

The risk of severe infectious complications associated with provision of medical care continues to be a pressing issue in modern surgery. Legionella pneumophila, characterized by its wide distribution in water supply systems and is highly active in film formation, represents a dangerous/important cause of hospital-acquired pneumonia. Patients requiring immunosuppression, including organ transplant recipients, are in the special risk group. Prevention of hospital-acquired legionellosis in patients at risk is essential due to severe clinical manifestations and high mortality. Objective: to summarize the practical experience in detecting contamination of water supply systems by Legionella pneumophila strains in multidisciplinary hospitals in Moscow. Materials and methods. Isolation of Legionella pneumophila strains from water and biofilms of water supply systems in multidisciplinary hospitals in Moscow and serotyping of this pathogen using bacteriological, molecular genetic and enzyme immunoassay methods. Results. Legionella pneumophila content in water reached high levels. The peculiarities of Legionella pneumophila contamination of hot water supply systems included formation of stable biofilms, in which other hospital-acquired pathogens were also identified. The share of Legionella pneumophila «SG 1», which causes up to 80% legionellosis cases in the world, was 13% in the water of the hospitals surveyed. The most effective measures for prevention of legionellosis are actions aimed at ensuring water biosecurity. Conclusion. There are potential risks of disease in the surgical wards of hospitals providing medical care, including in immunocompromised patients. Due to potential risks, prevention of hospital-acquired legionellosis is a necessary component of ensuring the safety of treatment for immunosuppressed patients.

Legionellosis Caused by Non-Legionella pneumophila Species, with a Focus on Legionella longbeachae.

Although known as causes of community-acquired pneumonia and Pontiac fever, the global burden of infection caused by Legionella species other than Legionella pneumophila is under-recognised. Non-L. pneumophila legionellae have a worldwide distribution, although common testing strategies for legionellosis favour detection of L. pneumophila over other Legionella species, leading to an inherent diagnostic bias and under-detection of cases. When systematically tested for in Australia and New Zealand, L. longbeachae was shown to be a leading cause of community-acquired pneumonia. Exposure to potting soils and compost is a particular risk for infection from L. longbeachae, and L. longbeachae may be better adapted to soil and composting plant material than other Legionella species. It is possible that the high rate of L. longbeachae reported in Australia and New Zealand is related to the composition of commercial potting soils which, unlike European products, contain pine bark and sawdust. Genetic studies have demonstrated that the Legionella genomes are highly plastic, with areas of the chromosome showing high levels of recombination as well as horizontal gene transfer both within and between species via plasmids. This, combined with various secretion systems and extensive effector repertoires that enable the bacterium to hijack host cell functions and resources, is instrumental in shaping its pathogenesis, survival and growth. Prevention of legionellosis is hampered by surveillance systems that are compromised by ascertainment bias, which limits commitment to an effective public health response. Current prevention strategies in Australia and New Zealand are directed at individual gardeners who use potting soils and compost. This consists of advice to avoid aerosols generated by the use of potting soils and use masks and gloves, but there is little evidence that this is effective. There is a need to better understand the epidemiology of L. longbeachae and other Legionella species in order to develop effective treatment and preventative strategies globally.

Risks of legionella pneumonia in patients receiving immunosuppressive therapy

The legionellosis infection associated with medical care is usually registered for patients with reduced immunity, including those receiving immunosuppressive therapy. Prevention of nosocomial legionellosis in patients is essential due to high mortality. The aim . Analyze of the potential risks of legionellosis infection in patients of surgical departments. Materials and methods . Isolation of Legionella pneumophila from water supply systems in Moscow hospitals and serotyping of the isolated microorganism was performed using bacteriological, molecular genetic and enzyme immunoassay methods. Results and discussion . The study showed that there are potential risks of disease in surgical departments of hospitals that provide medical care, including immunocompromised patients. The content of Legionella pneumophila in water reached 10 5 CFU/l. The share of Legionella pneumophila SG 1, which causes up to 80 % of cases of legionellosis in the world, is 13 % in the water of the surveyed hospitals. The only action prevention of legionellosis is the biological safety of water. Conclusion . Due to the presence of potential risks, prevention of legionellosis is a necessary component of ensuring the safety of the treatment process for patients with immunosuppression.

Misconceptions, not evidence guide occupational physicians’ decisions on legionellosis prevention

Abstract Introduction Legionnaire’s diseases (LD) is a significant cause of community-acquired pneumonia. An increasing number of cases has been linked with occupational exposures. The aim of this study was understanding knowledge, attitudes and practices of occupational physicians (OPh) towards LD. Methods A questionnaire-based cross-sectional study (April 2019), collecting a convenience sample of OPh operating in the Parma Province. Knowledge status (KS), Risk Perception (RP), and actual participation to the LD risk assessment were assessed. Multivariate odds ratios (mOR) for factors associated with participation to the LD risk assessment were calculated by means of a binary logistic regression analysis. Results 80 OPh participated to the survey (76.9% participation rate; mean age 48.2±11.2 years): even though the majority of them assisted at least one enterprise at potentially high risk for LD (i.e. 41.4% retirement houses, 27.1% water treatment plants including spas and pools, 25.7% hospitals) only 42.9% had participated to the LD risk assessment. The majority of OPh did not acknowledge diabetes (52.9%), cancer (65.7%), alcoholism (77.1%) as risk factors for LD, while a large share of OPh did not recognize hospital (50.0%), retirement houses (48.6%), swimming pools (48.6%) and spas (35.7%) as high risk environments. Moreover, participants underestimated both actual frequency (&amp;gt;1000 cases/year) and severity (lethality 10-15%) of LD in Italy, and occupational RP was not coincidentally low (43.2%±20.3). Participants reporting better KS were more likely to participate to the risk assessment (mOR 4.82 95%CI 1.06-21.94), while RP was eventually unrelated with preventive practices. Conclusions OPhs were diffusely affected by significant knowledge gaps on the actual risk factors for LD. Their misperceptions have the potential to negatively influence daily practice, impairing prevention of LD on the workplaces, and should be specifically targeted by information campaigns. Key messages Occupational Physicians were affected by significant knowledge gaps, particularly on individual and occupational risk factors for legionnaire disease. In order to better address the increasing threat of Legionnaire Disease, Occupational Physicians should be specifically targeted by information campaings.

Legionella control in a tertiary care hospital in Italy: adapting solutions to changing scenarios

Abstract Background Legionella contamination of hospital water distribution system still remains a critical issue in healthcare settings, despite the disputed relationship between environmental legionella and hospital-acquired legionellosis. We report the experience of our 1200-beds hospital, where a new water safety plan (WSP) has been applied since 2017, and the results obtained with the application of different methods to control Legionella water contamination, especially in critical areas. Methods Policlinico San Martino is the referral tertiary acute-care university hospital in Liguria region, North-West Italy. It’s made of 21 buildings of different dimensions, 7 of which host high risk patients, according to Italian Guidelines for legionellosis prevention and control. A sampling plan for Legionella detection was implemented in 2017, focusing on the water network critical points. Different secondary disinfection procedures were used, including systemic (chlorine dioxide, monochloramine), focal (point-of-use filtration) and short-term methods (hyperchlorination), the last in case of contamination higher than 10^4 CFU/l. Results Respectively, during 2017 and 2018 a total of 201 and 119 hot water samples were collected, distributed among the 7 critical buildings of the hospital. Negative samples raised from 69.7% to 74.8%, while positive samples &amp;gt;10^3 CFU/l (recommended cut-off for acute disinfection according to Italian guidelines) lowered from 21.9% to 9.2% of total samples. Out of 55 positive samples, Legionella sg 3 accounted for 98.2% of the total. Conclusions The new WSP determined a significant reduction of Legionella contamination of water distribution networks in our hospital critical buildings. The continuous surveillance of critical water system points provided evidence to elaborate an effective protocol for routine and extraordinary disinfection interventions, as result of a close collaboration between hospital hygiene unit and engineering and technical services. Key messages The implementation of an effective water safety plan and different disinfection procedures in hospital critical areas allow us to reduce and control the risk of hospital-acquired Legionella infection. Continuous surveillance cultures of drinking water to detect Legionella are necessary to adapt disinfection methods to local results.

ANALYSIS OF THE DIFFERENT METHODICAL APPROACHES DIRECTED ON THE ELIMINATION OF PLANKTON FORMS AND LEGIONELLA BIOFILMS FROM POTENTIALLY DANGEROUS WATER SYSTEMS

Aim. Comparative study of the different methodical approaches directed on the elimination of plankton forms and Legionella biofilms from potentially dangerous water systems. Materials and methods. Evaluation of short-term heatingof water to 70OC implemented in water supply module by volume 290 L with regulated temperature profile. Evaluation of catalytic cleansing of water implemented in the pool for water birds by volume 10 000 L. The initial, intermediate and final level of water objects colonization by L. pneumophila determined accordance MUK 4.2.2217-07. Presence of biofilms associated with L .pneumophila on the surface of the equipment, water surface and ball valves of water supply system determined visual with subsequent bacteriological confirmation by L. pneumophila isolation from biofilms. Results. The high level of bactericidal activity against L. pneumophila plankton forms and biofilms was shown by both methods. Short-term heating to 70O during 24 hours prevented Legionella growth for 2 months of management. The catalytic cleansing of water against high initial level of contamination of water object by L. pneumophila manifested not earlier 3 weeks of maintenance and continued during 2 months. Conclusion. The presented methodical approaches can be used for development of efficient strategy of prevention of legionellosis during management of the different potentially dangerous water systems in public buildings.

Implementation of a Legionella Ordinance for Multifamily Housing, Garland, Texas.

Context:The incidence of legionellosis has sharply increased in the United States as a result of contaminated water systems. Jurisdictions across the country are considering whether to develop and implement regulations to protect individuals against Legionnaires' disease with its associated high morbidity and mortality.Objective:This article sheds light on the implementation and effectiveness of a 2005 citywide Legionella testing mandate of multifamily housing cooling towers in Garland, Texas. This ordinance has been in place for more than 10 years and represents the first of its kind in the United States to mandate routine testing of cooling towers for Legionella in multifamily housing.Design, Setting, and Population:We utilized a mix of both qualitative and quantitative methods to explore the development, adoption, and implementation of the ordinance. Phone interviews were conducted with individuals from the City of Garland Health Department and apartment managers. Quantitative data included public health surveillance data on legionellosis.Main Outcome Measures:Barriers and facilitators of implementation, number and percentage of cooling towers from multifamily housing units that tested positive for Legionella by year, and number of legionellosis cases by year in Garland, Texas.Results:Study outcomes highlight key themes that facilitated the successful implementation of the Legionella testing mandate, including the importance of timing, leadership support, stakeholder engagement, and education and outreach. The number of contaminated cooling towers was reduced over time.Conclusion:Mandatory monitoring for legionella in a local jurisdiction may result in reduced risk of legionellosis from cooling towers through raising awareness and education of building owners and managers about the need to prevent, detect, and remediate legionella contamination in their building water systems. Garland, Texas, broke new ground in the United States in moving toward primary prevention of legionellosis. The ordinance may be useful both in serving to educate and increase awareness about the need for Legionella prevention and to monitor effectiveness of maintenance procedures.

Detection of viable but non-culturable legionella in hospital water network following monochloramine disinfection

Prevention of legionellosis remains a critical issue in healthcare settings where monochloramine (MC) disinfection was recently introduced as an alternative to chlorine dioxide in controlling Legionella spp. contamination of the hospital water network. Continuous treatments with low MC doses in some instances have induced a viable but non-culturable state (VBNC) of Legionella spp. To investigate the occurrence of such dormant cells during a long period of continuous MC treatment. Between November 2010 and April 2015, 162 water and biofilm samples were collected and Legionella spp. isolated in accordance with standard procedures. In sampling sites where MC was <1.5mg/L, VBNC cells were investigated by ethidium monoazide bromide (EMA)-real-time polymerase chain reaction (qPCR) and 'resuscitation' test into Acanthamoeba polyphaga CCAP 1501/18. According to the Health Protection Agency protocol, free-living protozoa were researched in 60 five-litre water samples. In all, 136 out of 156 (87.2%) of the samples taken from sites previously positive for L.pneumophila ST269 were negative by culture, but only 47 (34.5%) negative by qPCR. Although no positive results were obtained by EMA-qPCR, four out of 22 samples associated with MC concentration of 1.3±0.5mg/L showed VBNC legionella resuscitation. The presence of the amoeba A.polyphaga in the hospital water network was demonstrated. Our study is the first report evidencing the emergence of VNBC legionella during a long period of continuous MC treatment of a hospital water network, highlighting the importance of keeping an appropriate and uninterrupted MC dosage to ensure the control of legionella colonization in hospital water supplies.

Legionellosis Prevention and Response Training for Environmental Health Professionals

Legionellosis Prevention and Response Training for Environmental Health Professionals

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

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. To identify and describe policies and guidelines for the primary prevention of legionellosis in the US. 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. Federal, state, and local governing bodies and professional organizations. 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. 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.

SURVEY OF HOT WATER TEMPERATURES IN CAMPGROUNDS: ELEVATED SCALDING RISK AND ENERGY WASTAGE

BackgroundScalds from domestic hot water are an important public health problem in New Zealand (NZ).AimsWe aimed to study the hot water hazard in a yet unstudied setting: that of campgrounds.MethodsConvenience...

Healthcare Associated Legionellosis Prevention Within a Large Acute Care Center

An estimated 8,000 to 18,000 cases of legionnaire's disease occur in the United States each year, 25-45% of which are health care associated. Hospital surveys have detected Legionella contamination of the water supply in 12-70% of hospitals. Transmission to patients is felt to occur by inhalation of aerosols or ingesting contaminated potable water containing Legionella and has been more closely correlated with the number of sites testing positive rather than the quantitative cultures; >30% of sites with positive cultures has been associated with hospital acquired cases. (Marking of resource bibliography to be added at time of Presentation)

MORPHOLOGICAL FEATURES OF BIOFILMS IN POTENTIALLY DANGEROUS WATER SYSTEMS

The specific features of the structural organization of biofilms formed with the participation of Legionella in the water supply systems of health care facilities (HCF) and in the water-cooling towers of industrial enterprises in the Moscow Region were studied to elaborate new approaches to preventing legionellosis in the potentially dangerous water systems. A massive Legionella biofilm in association with other gram-positive and gram-negative bacteria was shown to form for 2-3 weeks on the protective antibacterial filters built in the hot water supply systems of the risk-group units of HCFs. The specific features of the structural organization of biofilms of Legionella onto surface of water-cooling towers, which were a set of a few systematic groups of microorganisms, such as fungi, gram-positive and gram-negative bacteria, and cyanobacteriae located in the presence of a matrix and metal inclusions. The results confirm that it is necessary to destruct and prevent the formation of natural Legionella biofilms in the potentially dangerous water systems, which is an essential component of the current strategy for the prevention of legionellosis.

Multiple regression as a preventive tool for determining the risk of Legionella spp.

&lt;p&gt;&lt;strong&gt;Objective&lt;/strong&gt;. To determine the interrelationship between health &amp;amp; hygiene conditions for prevention of legionellosis, the composition of materials used in water distribution systems, the water origin and Legionella pneumophila risk. &lt;strong&gt;Material and methods&lt;/strong&gt;. Include a descriptive study and multiple regression analysis on a sample of golf course sprinkler irrigation systems (n=31) pertaining to hotels located on the Costa del Sol (Malaga, Spain). The study was carried out in 2009.&lt;strong&gt; Results&lt;/strong&gt;. Presented a significant lineal relation, with all the independent variables contributing significantly (p&amp;lt;0.05) to the model’s fit. The relationship between water type and the risk of Legionella, as well as the material composition and the latter, is lineal and positive. In contrast, the relationship between health-hygiene conditions and Legionella risk is lineal and negative. &lt;strong&gt;Conclusion&lt;/strong&gt;. The characterization of Legionella pneumophila concentration, as defined by the risk in water and through use of the predictive method, can contribute to the consideration of new influence variables in the development of the agent, resulting in improved control and prevention of the disease.&lt;/p&gt;&lt;p&gt;&lt;br /&gt;&lt;strong&gt;Key words&lt;/strong&gt;: Legionella pneumophila, legionnaires’ disease, multiple regression, hotel golf courses, sprinklers.&lt;/p&gt;

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

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.

Legionellosis prevention in France

Since 1997, both the prevention of legionellosis and the control of Legionella in water networks and cooling towers have greatly improved in France. The epidemiological surveillance of Legionnaires' disease showed an increase, which was followed by a decrease in the incidence after a maximum was reached in 2005 (incidence rate of 2.5 per 10(5)). A steady decrease in the incidence rate has been observed since 2006, mainly due to the efficacy of control measures both for cooling towers and hospital water networks. In hospitals, a proactive approach was proposed in 1998 and quantitative limit values with systematic survey were put into force in 2002. The percentage of nosocomial cases has decreased dramatically and is now around 6-7% of all cases recorded in France. No nosocomial outbreak has been reported in recent years. However, this is not the case for community cases linked to diverse exposure sources, including cooling towers.