Control Of Legionellosis Research Articles

The one health approach applied to surveillance and control of Legionnaires’ disease in Switzerland

Abstract Issue/problem Legionnaires’ disease numbers have been increasing in Switzerland since 2001. With a reporting rate of 6.5 / 100'000 inhabitants in 2022, Switzerland has one of the highest incidences in Europe. The reported cases are mainly severe, about 87 % are diagnosed by hospitals, about 5 % have already died at the time of reporting. In the majority of cases the infection source is unknown. Description of the problem Because the causative agent, Legionella spp., is ubiquitous in humid environments, including building plumbing systems, a collaborative, multisectoral and transdisciplinary approach is key for an efficient response to this public health threat. Results At the national level, a close collaboration between the federal offices for public health, food safety (public shower and bath water) and energy (buildings and energy) was established in 2019 with the creation of a dedicated legionellosis expert group. Goals were to strengthen the coordination and to improve measures to combat the observed increase. Lessons Stakeholders from authorities responsible for implementing measures but also building and sanitary experts, specialists in cooling technology, laboratory experts and scientists have been involved in multiple activities coordinated by the national legionellosis expert group. Together they revise recommendations for prevention and control of legionellosis, and develop factsheets for building technology engineers and an outbreak investigation toolbox. A coordinated communication to the public is ensured, for example in view of possible energy shortage measures. Knowledge gaps have been identified and scientific research to fill them is coordinated, mutually funded and the results will be transferred into practice in the coming years. Key messages • The One Health approach has proven to be very effective in coordination of activities and communication. • The future will reveal if the joint efforts will have an impact on the high incidence.

Molecular characteristics of Legionella pneumophila in shower water of public places in Ma'anshan city from 2019 to 2020

Objective: To understand the epidemiological and pathogenic characteristics of Legionella pneumophila in shower water of public places in Ma'anshan City from 2019 to 2020, and to provide scientific basis for further prevention and control of legionellosis. Methods: From 2019 to 2020, according to population density distribution and business scale of bathing places in the main urban area of Ma'anshan City (Huashan District and Yushan District), 8 public bathing places (including 3 large, 3 medium and 2 small) were selected to collect 308 shower water and water storage pool water samples (294 shower water samples and 14 water storage pool water samples). After the collected water samples were treated, cultured, isolated and identified, the type characteristics of Legionella pneumophila were analyzed. Results: Legionella pneumophila were detected in 120 water samples among 308 shower water and water storage pool water samples, with an overall positive rate of 39.0% (120/308). A total of 154 Legionella pneumophila strains were detected, including 10 different serotypes, predominated by serotype 1 (LP1) and serotype 3 (LP3), accounting for 40.9% (63/154) and 22.7% (35/154). Among 154 strains of Legionella pneumophila, 23 strains of Legionella pneumophila were positive for all 14 virulence genes, accounting for 14.9% (23/154), including 19 serotype 1 (LP1) and 4 serotype 8 (LP8). Pulsed field gel electrophoresis (PFGE) cluster analysis of 154 Legionella pneumophila strains showed 60 different patterns. Conclusion: Legionella pneumophila was seriously polluted in the shower water environment of public places in Ma, anshan City. The serotypes are widely distributed and the virulence of the strains is strong. The results of molecular typing show that these strains have genetic diversity.

Investigation of Legionella contamination in artificial water environment of public places and identification of its pathogenic types in Shanghai from 2011 to 2018

Objective: To understand the epidemiological and pathogenic characteristics of Legionella in artificial water environment of public places in Shanghai from 2011 to 2018, and to provide scientific basis for the prevention and control of Legionellosis. Methods: A total of 4 817 samples of artificial water environment were collected from 31 public places in Huangpu, Jing'an, Xuhui and Songjiang districts of Shanghai from 2011 to 2108. Epidemiological characteristics of the collected years and months, regional and site types, and sample types were analyzed. After treatment, culture and isolation of the collected water samples, the positive samples were analyzed for Legionella typing characteristics. Results: The positive rate of Legionella pneumophila was 21.57% (1 039/4 817), of which 96.25% (1 000/1 039) was single type, 84.31% (876/1 039) was Legionella pneumophila type 1, followed by Legionella pneumophila type 7 and 6, which accounted for 4.72% (49/1 039) and 3.75% (39/1 039), respectively, and 29 (29/1 039) were multi-type positive. Further typing. From May to October, the highest positive rates were found in July and August, 27.61%(222/804)and 28.61% (230/804)respectively. There were significant differences between different months (P<0.001); the highest positive rates were found in central air-conditioning cooling water and chilled water (32.40%) and there were significant differences among different water samples (P<0.001). Legionella pneumophila type 1, type 7 and type 6 were the main diversity distribution characteristics in artificial water environment of different regions, different time, different places and different types of public places. Legionella pneumophila type 1 accounted for the highest proportion, and the proportion of positive samples under different epidemiological characteristics was more than 71.64%. Conclusion: There is relatively serious pollution of Legionella pneumophila type 1 in the artificial water environment of public places in Shanghai. It is necessary to strengthen the disinfection of cooling water/freezing water of central air conditioning in public places in July and August every year.

Detection of &amp;lt;i&amp;gt;Legionellae pneumophila&amp;lt;/i&amp;gt; in Waters by Culture and Polymerase Chain Reaction

Legionella pneumophila (L. pneumophila) is the most common causative agents for all outbreaks of Legionnaires’ disease. Prevention and control of Legionellosis requires surveying and monitoring of Legionella in the environment using conventional and modern technologies. The present study aims to compare detection of L. pneumophila in water samples using both culture and PCR techniques. A pre-enriched contaminated water sample was split into 13 subsamples. Culture and PCR tests were done from the subsamples after different intervals. The results showed a positive PCR result for L. pneumophila after 8 h of incubation. Also, L. pneumophila was detected by culture on non-selective BCYNE agar and selective GPVC agar after 5 and 6 days of incubation respectively. There was no significant difference between the non-selective BCYE- and the selective GVPC method. The PCR procedure was found more sensitive and differed significantly from the conventional selective GVPC method in isolation of L. pneumophila from water samples. It was concluded that pre-enrichment incubation allows the detection of L. pneumophila by PCR within a maximum of 12 h from the collection of water samples.

Legionelosis asociada con viajes en España, serie 1997-2002

Objetivo: analizar el desarrollo de la legionelosis en España durante los años 1997-2002, mediante números crudos, y su relación con el European Surveillance Scheme for Travel Associated Legionnaires’ Disease. La legionelosis es una enfermedad respiratoria que puede resultar mortal. En España es considerada como de declaración obligatoria desde 1995. En 1986 se creó The European Working Group for Legionella Infections y al año siguiente el European Surveillance Scheme for Travel Associated Legionnaires’ Disease. Materiales y métodos: estudio de carácter descriptivo mediante la recopilación de los casos, brotes y defunciones por legionelosis, para la serie indicada, a través de las notificaciones efectuadas al Centro Nacional de Epidemiología. Resultados: se determina la implicación en el ámbito comunitario, nosocomial y el European Surveillance Scheme for Travel Associated Legionnaires’ Disease. Esta afecta al número total en todos los ámbitos y, en especial, en los brotes, casos y defunciones en los años 1997, 1998 y 2000; mientras que los mayores registros para estos eventos en la serie estudiada acontecieron en los años 2002 (62), 2001 (772) y 2000 (25), respectivamente. Conclusiones: la vigilancia epidemiológica constituye una herramienta muy valiosa para la prevención y control de la enfermedad. El análisis de las series temporales puede arrojar información relevante del comportamiento de la legionelosis y de las fuentes de desarrollo del agente inductor de la enfermedad.

Ten questions concerning the aerosolization and transmission of Legionella in the built environment

Legionella is a genus of pathogenic Gram-negative bacteria responsible for a serious disease known as legionellosis, which is transmitted via inhalation of this pathogen in aerosol form. There are two forms of legionellosis: Legionnaires' disease, which causes pneumonia-like symptoms, and Pontiac fever, which causes influenza-like symptoms. Legionella can be aerosolized from various water sources in the built environment including showers, faucets, hot tubs/swimming pools, cooling towers, and fountains. Incidence of the disease is higher in the summertime, possibly because of increased use of cooling towers for air conditioning systems and differences in water chemistry when outdoor temperatures are higher. Although there have been decades of research related to Legionella transmission, many knowledge gaps remain. While conventional wisdom suggests that showering is an important source of exposure in buildings, existing measurements do not provide strong support for this idea. There has been limited research on the potential for Legionella transmission through heating, ventilation, and air conditioning (HVAC) systems. Epidemiological data suggest a large proportion of legionellosis cases go unreported, as most people who are infected do not seek medical attention. Additionally, controlled laboratory studies examining water-to-air transfer and source tracking are still needed. Herein, we discuss ten questions that spotlight current knowledge about Legionella transmission in the built environment, engineering controls that might prevent future disease outbreaks, and future research that is needed to advance understanding of transmission and control of legionellosis.

Prevention and control of legionellosis: A public health perspective

Prevention and control of legionellosis: A public health perspective

Acciones de prevención y control de la legionelosis: un reto para la salud pública española

Legionellosis is a respiratory disease originating in systems that produce aerosol and contain Legionella sp. In recent decades, Spain has developed a regulatory framework for prevention and control of legionellosis. This article describes the epidemiology of legionellosis and the importance of controlling the transmission of bacteria in the fight against the disease. In that regard, it becomes clear the role of reviewing critical facilities and the inclusion of new ones in the preventive legislation, the estimation of risk, and the improvement in the diagnostic processes and progress in new prevention protocols.

P182: Detection of legionella pneumophila DNA from environment of hospitals

The risk of infection and epidemiological surveillance and control of legionellosis depends on the challenges of detecting the Legionella pneumophila DNA in the hospital environment.

Risk for Travel-associated Legionnaires’ Disease, Europe, 2009

Legionnaires' disease is underreported in Europe; notification rates differ substantially among countries. Approximately 20% of reported cases are travel-associated. To assess the risk for travel-associated Legionnaires' disease (TALD) associated with travel patterns in European countries, we retrieved TALD surveillance data for 2009 from the European Surveillance System, and tourism denominator data from the Statistical Office of the European Union. Risk (number cases reported/number nights spent) was calculated by travel country. In 2009, the network reported 607 cases among European travelers, possibly associated with 825 accommodation sites in European Union countries. The overall risk associated with travel abroad was 0.3 cases/million nights. We observed an increasing trend in risk from northwestern to southeastern Europe; Greece had the highest risk (1.7). Our findings underscore the need for countries with high TALD risks to improve prevention and control of legionellosis; and for countries with high TALD risks, but low notification rates of Legionnaires' disease to improve diagnostics and reporting.

Acciones de prevención y control de la legionelosis: un reto para la salud pública española

Legionellosis is a respiratory disease originating in systems that produce aerosol and contain Legionella sp. In recent decades, Spain has developed a regulatory framework for prevention and control of legionellosis. This article describes the epidemiology of legionellosis and the importance of controlling the transmission of bacteria in the fight against the disease. In that regard, it becomes clear the role of reviewing critical facilities and the inclusion of new ones in the preventive legislation, the estimation of risk, and the improvement in the diagnostic processes and progress in new prevention protocols.

Epidemiology and control of legionellosis, singapore.

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

P11.18 Environmental surveillance strategy for the prevention and control of Legionellosis

P11.18 Environmental surveillance strategy for the prevention and control of Legionellosis

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

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. 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. 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. 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.

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

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.

A small outbreak of Legionnaires' disease in a cargo ship under repair.

It was reported that two mechanics working on a cargo ship under repair in the port of Barcelona had died after having fever. An investigation was made into the possibility of any additional cases and the presence of Legionella pneumophila in the ship they were repairing and in their hotel. The contaminated water system was treated with sodium hypochlorite. Both patients died after having been repeatedly diagnosed as having influenza. The two cases occurred among those who had been working with the pump of the ship's water system, while no cases were observed among the other workers (p = 0.02). Various serogroups of L. pneumophila were isolated from the ship's water pump and distribution system. However, organism of serogroup 1, subgroup Pontiac (Knoxville) were identified with identical deoxyribonucleic acid (DNA) patterns in the lung tissue of one patient and in the cooling water circuit valve of the ship's water pump. The first postintervention control water samples showed no further growth of legionella, but serogroups 4 and 8 were identified 8 months later. This legionellosis outbreak, although small, was highly lethal, probably due to the high levels of bacteria to which the patients were exposed and also because of the failure of correct diagnosis. International recommendations on prevention and control of legionellosis, which include ships under repair, are required.

The control of legionellosis - recommended code of conduct for service providers

The control of legionellosis - recommended code of conduct for service providers

Prevention and Control of Legionellosis

Prevention and Control of Legionellosis

96/06676 The prevention or control of legionellosis (Including legionnaires' disease)

96/06676 The prevention or control of legionellosis (Including legionnaires' disease)

Preventing Legionellosis:Is Your Action Plan Completed?

Concentrates on the fact that Britain has had an unusually large proportion of cases of legionnaires′ disease. Reminds employers of obligations of buildings legislation from the Health and Safety at Work Act and The Code of Practice on Prevention or Control of Legionellosis (which came into force on 10 April 1991). Reports on the history of legionellosis; the infection route; actions for employers to take to prevent infection. Indicates that outbreaks of the disease in a company is traumatic regarding staff relations and personal tragedy; it can also be expensive as insurance companies no longer look upon outbreaks as “Acts of God”.