Legionella pneumophila: un patógeno emergente en Argentina / Legionella pneumophila: an emerging pathogen in Argentina

La enfermedad del Legionario es causada por bacterias pertenecientes al género Legionella, siendo la especie pneumophila el principal agente etiológico de esta patología. Esta bacteria se describió por primera vez en 1977 como causa de un brote de neumonía grave registrado en 1976 en un centro de convenciones en los Estados Unidos de América. La enfermedad se presenta como una neumonía atípica, responsable del 1 al 15 % de los casos de neumonías adquiridas en la comunidad (NAC), del 5 al 10% de neumonías del adulto y del 1% en menores de 15 años. Los miembros de la familia Legionellaceae son bacilos aeróbicos gramnegativos que crecen lentamente y se encuentran ampliamente distribuidos en cuerpos de agua. La forma más común de transmisión de Legionella spp es la inhalación de aerosoles contaminados generados a partir de fuentes de agua artificiales. Se asocian con la aparición de brotes esporádicos y epidémicos en la comunidad y en infecciones nosocomiales. Las especies pertenecientes al género Legionella se consideran patógenos emergentes transmitidos por el agua. El objetivo de este trabajo es realizar una revisión sobre las manifestaciones y presentaciones clínicas de la infección causada por L. pneumophila, en virtud de que es considerado mundialmente un patógeno emergente y por existir evidencias de su presencia en sistemas de almacenamiento de agua tratada en la región nordeste de la República Argentina, razón primordial para alertar y actualizar conocimientos al respecto

Legionnaires' disease is caused by bacteria belonging to the genus Legionella, being the pneumophila specie the main etiological agent of this pathology. This bacterium was first described in 1977 as the cause of a severe pneumonia outbreak in 1976 at a convention center in the United States of America. The disease presents as an atypical pneumonia, responsible for 1% to 15% of cases of community-acquired pneumonia (CAP), 5% to 10% of pneumonia in adults and 1% in children under 15 years of age. Members of the Legionellaceae family are aerobic, gram-negative rods that grow slowly and are widely distributed in water bodies. The most common way of transmission of Legionella spp is the inhalation of contaminated aerosols generated from artificial water sources. They are associated with the appearance of sporadic and epidemic outbreaks in the community and in nosocomial infections. Species belonging to the genus Legionella are considered emerging waterborne pathogens.The aim of this work is to carry out a review on the manifestations and clinical presentations of the infection caused by L. pneumophila, due to that it is considered an emerging pathogen worldwide and because there is evidence of its presence in storage systems of treated water in the Northeast region of the Argentine Republic, primary reason to alert and update knowledge in this regard.

[Legionnaires' disease prevention protocol performance in public buildings]. / Cumplimiento de los Protocolos de Prevención de la Legionelosis en Edificios Públicos.

OBJECTIVE: Studying the relationship between fulfilment of royal decree 865/2003 and decree 287/2002 (establishing hygienic-sanitary criteria for preventing and controlling Legionnaires' disease) and risk arising from deficient preventative-hygienic water facility maintenance. METHODS: This was a descriptive study carried out in the province of Málaga (Spain) on a sample of 214 public buildings using 83 variables and interpreting legislation fulfilment percentages. Risks were measured, clusters defined (related to risk typification) and classic and robust estimators, jack-knife estimation and bootstrap confidence intervals were calculated. RESULTS: 11.1 % (irrigation, ESO private centres) and 85.7 % (AFS, secondary education institutions) partial non-fulfilment/breach risks were found. Eighty-two buildings complied with current standards, 130 failed to fulfil them and 2 did not display risk facilities. There was 38 % overall compliance with established norms. Location parameter fulfilment was estimated as being 0.33-0.36 (3336 %) and scale as 0.110.16. Reduced bias jack-knife estimator was 0.35071 (average estimation). Bootstrap confidence interval extremes were 0.26 and 0.47. CONCLUSION: Secondary education institutions represented the least risk due to partial noncompliance and four- and three-star hotels the greatest. Huber estimator was selected as location parameter and NMAD as scale parameter. Regarding the population ratio parameter and sample ratio estimator, it was considered that the jack-knife estimator of reduced bias was unbiased. Confidence intervals based on bootstrap techniques (starting from 0.2trimmed mean sample and a 0.95 confidence coefficient) were very approximate.

Cumplimiento de los protocolos de prevención de la legionelosis en edificios públicos / Legionnaires' disease prevention protocol performance in public buildings

Objetivo Investigar la relación entre el cumplimiento del Real Decreto 865/2003 y el Decreto 287/2002, por los que se establecen los criterios higiénico-sanitarios para la prevención y control de la legionelosis, y el riesgo debido a un deficiente mantenimiento higiénico- preventivo de las instalaciones de agua. Métodos Estudio descriptivo realizado en la provincia de Málaga (España) sobre una muestra correspondiente a 214 edificios públicos, 83 variables e interpretación sobre el porcentaje de cumplimiento de la normativa. Medida del riesgo, definición de clusters (tipificación del riesgo), estimadores clásicos y robustos, estimación jackknife e intervalos de confianza bootstrap . Resultados Riesgo por incumplimiento parcial entre el 11,1 (riego, Centros Privados de ESO) y 85,7 por ciento (AFS, Institutos de Educación Secundaria). La normativa se cumple en 82 edificios, 130 la incumplen y 2 no presentan instalaciones de riesgo. Cumplimiento total 38 por ciento. Estimación para el cumplimiento parámetros de localización 0,33-0,36 (33-36 por ciento) y de escala 0,11-0,16. Estimador jackknife del sesgo reducido 0,35071 (estimación media). Intervalos de confianza bootstrap con extremos [0.26, 0.47]. Conclusión El menor riesgo por incumplimiento parcial corresponde a Institutos de Educación Secundaria y el mayor por distribución a los hoteles de cuatro y tres estrellas. Selección del parámetro de localización estimador de Huber y de escala NMAD . Atendiendo al parámetro "razón poblacional" y estimador "razón muestral", el estimador jackknife del sesgo reducido es insesgado. Intervalos de confianza basados en las técnicas bootstrap , partiendo de la media 0,2- recortada muestral y coeficiente de confianza 0,95, muy aproximados.

Objective Studying the relationship between fulfilment of royal decree 865/2003 and decree 287/2002 (establishing hygienic-sanitary criteria for preventing and controlling Legionnaires' disease) and risk arising from deficient preventative-hygienic water facility maintenance. Methods This was a descriptive study carried out in the province of Málaga (Spain) on a sample of 214 public buildings using 83 variables and interpreting legislation fulfilment percentages. Risks were measured, clusters defined (related to risk typification) and classic and robust estimators, jack-knife estimation and bootstrap confidence intervals were calculated. Results 11.1 percent (irrigation, ESO private centres) and 85.7 percent (AFS, secondary education institutions) partial non-fulfilment/breach risks were found. Eighty-two buildings complied with current standards, 130 failed to fulfil them and 2 did not display risk facilities. There was 38 percent overall compliance with established norms. Location parameter fulfilment was estimated as being 0.33-0.36 (3336 percent) and scale as 0.110.16. Reduced bias jack-knife estimator was 0.35071 (average estimation). Bootstrap confidence interval extremes were 0.26 and 0.47. Conclusion Secondary education institutions represented the least risk due to partial noncompliance and four- and three-star hotels the greatest. Huber estimator was selected as location parameter and NMAD as scale parameter. Regarding the population ratio parameter and sample ratio estimator, it was considered that the jack-knife estimator of reduced bias was unbiased. Confidence intervals based on bootstrap techniques (starting from 0.2trimmed mean sample and a 0.95 confidence coefficient) were very approximate.

Disconnecting central hot water and using electric showers to avoid colonization of the water system by Legionella pneumophila: an 11-year study.

Legionella spp. can be difficult to control in hospitals. The objective of this study was to describe an 11-year experience with the use of electric showers in the control of Legionella pneumophila. From June 1989 to March 1990 there was an outbreak of pneumonia caused by L. pneumophila in a 20-bed renal transplant unit in a university-associated tertiary-care hospital. Control measures included hyperchlorination, heating and flushing of the water system with limited results. In November 1993 the central hot water was disconnected and water for bathing was heated using electric showers. From January 1992 to June 1995 water was collected from showers and water faucets and cultured for L. pneumophila every two weeks. Surveillance cultures were then collected every month until May 1999. During this seven-year surveillance period, 1115 samples of water were cultured. Water cultures were positive on 24 of 429 occasions (without cases of legionellosis) during the pre-shower period (22 months). In the post-shower period (67 months) only one of 686 cultures was positive. Subsequently there have been no new cases of nosocomial pneumonia by L. pneumophila although surveillance continues. In conclusion, disconnecting the central hot water was effective in avoiding colonization of the water system by L. pneumophila. Heating was possible by using electric showers, which are effective, easy to maintain and cheap.

Doença dos legionários: uma revisão / Legionnaire's disease: a review

A doença dos legionários é uma patologia autolimitada semelhante à gripe, caracterizada por febre, cefaléia, mialgias e tosse não produtiva, estando, algumas vezes, relacionada com formas fatais de pneumonia. Tem como etiologia a infecção pela bactéria Legionella sp. Atualmente são conhecidas cerca de 40 espécies de Legionella, mas apenas cinco causam a doença em humanos.Legionella pneumophila é a principal espécie relacionada a casos em humanos. As legionelas encontram-se freqüentemente em reservatórios de água e crescem em água quente. Os sistemas de distribuição de água quente e as torres de resfriamento dos equipamentos de ar condicionado são identificados como as principais fontes de infecção. Vários testes laboratoriais estão disponíveis para o diagnóstico de legionela, incluindo cultura, aglutinação em lâmina com partículas de látex, radioimunoensaio, imunofluorescência direta e indireta e enzimaimunoensaio. O objetivo principal da vigilância da doença do legionário é a identificação de surtos, de forma a implementar medidas de controle. O presente trabalho descreve uma revisão sobre a doença dos legionários, visando a ampliar o conhecimento dos profissionais da saúde e da população em geral.

Legionnaire’s disease is a self-limiting pathology. Similar to cold, it is characterized by fever, headache, myalgias and non-productive cough, and sometimes connected with fatal pneumonia. Its etiology to infection is done through bacteria Legionella spp. Presently, about forty types of Legionella are known, but only five of them can cause disease to human beings. Legionella pneumphila is the main type related to human beings. Legionellas are usually found in water reservoirs, and grow in hot water. Both hot water distribution systems and air-conditioner tower cooling are identified as the main sources of infection. Many laboratory tests are available for Legionella diagnosis, including culture, agglutination on blade containing latex particles radioimmunoassay, direct and indirect immunofluorescence, and enzyme-linked immunosorbent assay. The main objective in checking legionnaire’s disease is to identify outbreaks, aiming at implementing control measurements. This article describes a review of legionnaire’s disease, intending to enlarge health professional and ordinary people’s knowledge on the field.

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

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.

Electric showers as a control measure for Legionella spp. in a renal transplant unit in São Paulo, Brazil. Legionellosis Study Team.

After an outbreak of legionnaires' disease Legionella pneumophila serogroup 1 in a renal transplant unit in São Paulo, Brazil, periodic hyperchlorination and flushing of pipes were instituted as control measures. These were only partially effective as every two to five months water cultures turned positive or new cases of the disease occurred. In November 1993 the hot water was disconnected from the unit and small, plastic electric showers were installed in each bathroom. Over a period of 12 months water from showers and taps was cultured for Legionella spp. every two weeks. On only one occasion was a water culture positive for L. pneumophila from a sink tap. No water sample obtained from showers was positive during the study period. No cases of legionnaires' disease occurred. We considered the use of electric showers an inexpensive and effective method of controlling the problem of Legionella spp. in the water system of our renal transplant unit.

Legionnaires' disease in the renal transplant unit of "Hospital das Clinicas, FMUSP". During a five year period (1988-1993).

Several reports have related Legionella pneumophila with pneumonia in renal transplant patients, however this association has not been systematically documented in Brazil. Therefore this paper reports the incidence, by serological assays, of Legionella pneumophila serogroup 1 in these patients during a five year period. For this purpose sera from blood samples of 70 hospitalized patients with pneumonia from the Renal Transplant Unit of Hospital das Clinicas, FMUSP collected at the acute and convalescent phase of infection were submitted to indirect immunofluorescence assay (IFA) to demonstrate anti-Legionella pneumophila serogroup 1 antibodies. Of these 70 patients studied during the period of 1988 to 1993, 18 (25.71%) had significant rises in specific antibody titers for Legionella pneumophila serogroup 1. Incidence was interrupted following Hospital water decontamination procedures, with recurrence of infections after treatment interruption. In this study, the high susceptibility (25.71%) of immunodepressed renal transplant patients to Legionella pneumophila serogroup 1 nosocomial infections is documented. The importance of the implementation and maintenance of water decontamination measures for prophylaxis of the infection is also clearly evident.

An outbreak of nosocomial Legionnaires' disease in a renal transplant unit in São Paulo, Brazil. Legionellosis Study Team.

From June 1989 to March 1990 there were eight cases of Legionnaires' disease caused by Legionella pneumophila serogroup 1 in a renal transplant unit. There were seven cases of pneumonia and one case of pleural effusion. A study was conducted to identify the source of the outbreak. Legionella anisa was cultured from tap water. Twenty-seven staff members of the unit were serologically tested and antibody titres were positive in two. The probable source of infection was the potable water system. Control measures were hyperchlorination and heating of the water, after which there were no further cases during 5 months' follow up. We believe this is the first reported Legionnaires' disease outbreak in Latin America.

Legionnaires' disease in the work environment: implications for environmental health.

Legionnaires' disease is a severe pneumonia caused by the bacterium Legionella pneumophila. Outbreaks of Legionnaire's disease have occurred in hotels, hospitals, and homes but had not been reported yet in the work environment. The authors report the occurrence of Legionnaires' disease in three employees of two industrial plants. The potable water in the two plants contained high numbers of Legionella pneumophila. Monoclonal antibody subtyping of environmental and patient isolates of L. pneumophila implicated one of the plants as the source for the disease. L. pneumophila was eradicated from this plant using acidic and caustic scale removers, calcium hypochlorite, and a biocide. A systematic approach to Legionnaires' disease in the work environment, a problem which can be expected to be recognized with increasing frequency, is presented.