Two species of cyanobacteria (Fischeralla sp. 29161 and Phormidium autumnale) and one species of green algae (Fritschiella tuberosa) were found to promote survival of Legionella pneumophila in mineral salts medium cocultures. During the early stage of incubation Fischerella sp. supported growth of Legionella pneumophila even though the bacteria would not grow in the algae-free basal medium.

Hospital-acquired Legionnaires¡¦ Disease (LD) is a bacterial pneumonia caused by the genus of Legionella. It is an opportunistic pathogen with the characteristic of widespread distribution in the environment. Its source of infection associates with potable water systems. Proactively culturing hospital water supply for Legionella as a strategy for prevention of nosocomial LD has been widely adopted in other countries. Nosocomial LDs has been hardly reported in Taiwan. In addition, environmental cultures of Legionella in potable water systems in hospitals have not been systematically implemented. Thus, the purpose of the research is to confirm if LD presents in the hospital in Taiwan, and developing risk management strategy in hospital-acquired LD. To practice one-year prospective surveillance program for LD, we choose a military hospital in Southern Taiwan, collecting the specimens from the nosocomial and community-acquired pneumonia patients for legionella investigations. In the meanwhile, we collect water samples for hospital epidemiological investigation every 3 months. Isolated Legionella pneumophila is serotyped and analyzed by pulsed-field gel electrophoresis. From Nov 1, 2006 to Oct 30, 2007, within 54 cases of nosocomial and 300 cases of community-acquired pneumonia, only one case of nosocomial LD was found. Environmental investigations detected L. pneumophila in 17(20.7%) of the 84 water samples, of which 82.4% (14/17) belonged to serogroup 1. The result demonstrated the infection source of the only positive case of nosocominal pneumonia is the potable water supply system of another hospital. In conclusion: 1. The infection source of nosocomial LD is the potable water supply system of the hospital. 2. The positive rate of distal outlets for L. pneumophila is a reasonable and reliable indicator in risk management for nosocomial LD. 3. Uncovered cases of nosocomial LD will be found in prospective clinical surveillance for LD. Suggestions: 1. Routine water-quality monitoring should be added in environmental water culture for L. pneumophila in the institution, such as hospital, nursing home, hotel, restaurant, SPA, swimming pool, hot spring, school, army, etc. 2. We advise that government health department carries out national surveillance for hospital water environment in determining the risk of hospital-acquired LD. 3. Education and training program need to be provided for medical staffs in the diagnostic skills of nosocomial LD to avoid misdiagnosing and delaying the treatment.

If cooling towers are poorly maintained there is a risk of microbial growth such as Legionella which in turn might spread via aerosols and infect humans. This may lead to an outbreak of legionnaires’ disease. The purpose of this study was to highlight the risks of Legionella and cooling towers along with investigating the legal responsibility of businesses and supervision authorities in this regard. The study also investigated whether business should be obligated to register their cooling towers at supervising authorities. The study was partly based on a survey which was sent to Sweden’s 290 municipalities and 21 county administration boards to investigate their knowledge regarding Legionella and cooling towers and if they had inventoried which of their facilities that uses cooling towers. The results of the survey showed that 16% of the municipalities and none of the county administration board had inventoried which of their facilities that uses cooling towers. Half of the municipalities do not have any knowledge if any of their facilities uses cooling towers. Moreover, 45% of the municipalities and 30% of the county administration boards consider that business should register their cooling towers. The results showed that many of Sweden’s municipalities and county administration boards have shortcomings in their knowledge and supervision. Legislation and priorities need to be assessed and regulatory guidance from the Public Health Agency of Sweden is necessary for future progress.

Cheng Yee Wan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 95-112). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Table of Contents --- p.vi / List of Figures --- p.xi / List of Plates --- p.xiv / List of Tables --- p.xvi / Abbreviations --- p.xviii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Legionella pneumophila --- p.1 / Chapter 1.1.1 --- Bacterial morphology and ultrastructure --- p.2 / Chapter 1.1.2 --- Microbial ecology and natural habitats --- p.4 / Chapter 1.1.2.1 --- Association with amoeba --- p.5 / Chapter 1.1.2.2 --- Association with biofilm --- p.5 / Chapter 1.2 --- Legionnaires' disease and clinical significance --- p.6 / Chapter 1.2.1 --- Epidemiology --- p.6 / Chapter 1.2.1.1 --- Worldwide distribution --- p.6 / Chapter 1.2.1.2 --- Local situation --- p.7 / Chapter 1.2.2 --- Clinical presentation --- p.7 / Chapter 1.2.3 --- Route of infection and pathogenesis --- p.8 / Chapter 1.2.4 --- Diagnosis --- p.10 / Chapter 1.2.4.1 --- Culture of Legionella --- p.10 / Chapter 1.2.4.2 --- Direct fluorescent antibody (DFA) staining --- p.13 / Chapter 1.2.4.3 --- Serologic tests --- p.13 / Chapter 1.2.4.4 --- Urine antigen testing --- p.14 / Chapter 1.2.4.5 --- Detection of Legionella nucleic acid --- p.15 / Chapter 1.2.5 --- Risk factors --- p.15 / Chapter 1.2.6 --- Treatment for Legionella infection --- p.16 / Chapter 1.3 --- Detection of Legionella in environment --- p.16 / Chapter 1.4 --- Disinfection methods --- p.17 / Chapter 1.4.1 --- Physical methods --- p.19 / Chapter 1.4.1.1 --- Filtration --- p.19 / Chapter 1.4.1.2 --- UV-C irradiation --- p.20 / Chapter 1.4.1.3 --- Thermal eradication (superheat-and-flush) --- p.21 / Chapter 1.4.2 --- Chemical methods --- p.21 / Chapter 1.4.2.1 --- Chlorination --- p.21 / Chapter 1.4.2.2 --- Copper-silver ionization --- p.22 / Chapter 1.4.3 --- Effect of biofilm and other factors on disinfection --- p.23 / Chapter 1.5 --- Photocatalytic oxidation (PCO) --- p.24 / Chapter 1.5.1 --- Generation of strong oxidants --- p.24 / Chapter 1.5.2 --- Disinfection mechanism(s) --- p.27 / Chapter 1.5.3 --- Major factors affecting the process --- p.28 / Chapter 2. --- Objectives --- p.30 / Chapter 3. --- Materials and Methods --- p.31 / Chapter 3.1 --- Chemicals --- p.31 / Chapter 3.2 --- Bacterial strains and culture --- p.31 / Chapter 3.3 --- Photocatalytic reactor --- p.33 / Chapter 3.4 --- PCO efficacy tests --- p.33 / Chapter 3.5 --- PCO sensitivity tests --- p.35 / Chapter 3.6 --- Optimisation of PCO conditions --- p.35 / Chapter 3.6.1 --- Optimization of TiO2 concentration --- p.36 / Chapter 3.6.2 --- Optimization of UV intensity --- p.36 / Chapter 3.6.3 --- Optimization of depth of reaction mixture --- p.36 / Chapter 3.6.4 --- Optimization of stirring rate --- p.37 / Chapter 3.6.5 --- Optimization of initial pH --- p.37 / Chapter 3.6.6 --- Optimization of treatment time and initial cell concentration --- p.37 / Chapter 3.6.7 --- Combinational optimization --- p.37 / Chapter 3.7 --- Transmission electron microscopy (TEM) --- p.38 / Chapter 3.8 --- Fatty acid profile analysis --- p.40 / Chapter 3.9 --- Total organic carbon (TOC) analysis --- p.42 / Chapter 3.10 --- UV-C irradiation --- p.44 / Chapter 3.11 --- Hyperchlorination --- p.44 / Chapter 3.12 --- Statistical analysis and replication --- p.45 / Chapter 3.13 --- Safety precautions --- p.45 / Chapter 4. --- Results --- p.46 / Chapter 4.1 --- Efficacy test --- p.46 / Chapter 4.2 --- PCO sensitivity --- p.47 / Chapter 4.3 --- Optimization of PCO conditions --- p.48 / Chapter 4.3.1 --- TiO2 concentration --- p.48 / Chapter 4.3.2 --- UV intensity --- p.48 / Chapter 4.3.3 --- Depth of reaction mixture --- p.51 / Chapter 4.3.4 --- Stirring rate --- p.56 / Chapter 4.3.5 --- Effect of initial pH --- p.56 / Chapter 4.3.6 --- Effect of treatment time and initial concentrations --- p.56 / Chapter 4.3.7 --- Combinational effects --- p.63 / Chapter 4.4 --- Transmission electron microscopy (TEM) --- p.66 / Chapter 4.4.1 --- Morphological changes induced by PCO --- p.66 / Chapter 4.4.2 --- Comparisons with changes caused by UV-C irradiation and chlorination --- p.67 / Chapter 4.5 --- Fatty acid profile analysis --- p.71 / Chapter 4.6 --- Total organic carbon (TOC) analysis --- p.73 / Chapter 4.7 --- UV-C irradiation --- p.74 / Chapter 4.8 --- Hyperchlorination --- p.74 / Chapter 5. --- Discussion --- p.76 / Chapter 5.1 --- Efficacy test --- p.76 / Chapter 5.2 --- PCO sensitivity --- p.76 / Chapter 5.3 --- Optimization of PCO conditions --- p.77 / Chapter 5.3.1 --- Effect of TiO2 concentration --- p.77 / Chapter 5.3.2 --- Effect of UV intensity --- p.78 / Chapter 5.3.3 --- Effect of depth of reaction mixture --- p.79 / Chapter 5.3.4 --- Effect of stirring rate --- p.79 / Chapter 5.3.5 --- Effect of initial pH --- p.80 / Chapter 5.3.6 --- Effect of treatment time and initial concentrations --- p.81 / Chapter 5.3.7 --- Combinational effect --- p.82 / Chapter 5.4 --- Transmission electron microscopy (TEM) --- p.83 / Chapter 5.4.1 --- Morphological changes induced by PCO --- p.83 / Chapter 5.4.2 --- Comparisons with changes caused by UV-C irradiation and chlorination --- p.85 / Chapter 5.5 --- Fatty acid profile analysis --- p.85 / Chapter 5.6 --- Total organic carbon (TOC) analysis --- p.86 / Chapter 5.7 --- Comparisons of the three disinfection methods --- p.88 / Chapter 6. --- Conclusion --- p.91 / Chapter 7. --- References --- p.95 / Chapter 8. --- Appendix --- p.113

Includes bibliographical references (leaves 115-120) Establishes a Bayesian Belief Network (BBN) to model uncertainty of aerosols released from cooling towers and Geographic Information Systems (GIS) to create a wind dispersal model and identify potential cooling towers as the source of infection. Demonstrates the use of GIS and BBN in environmental epidemiology and the power of spatial information in the area of health.

Seasonality, or a cycling of high and low incidence, of infectious diseases has long been recognized but remains little understood. For many diseases, even major ones such as influenza, our knowledge of the seasonal drivers is very limited. One proposed driver of seasonality for many diseases is weather, especially temperature and humidity. I studied how likely an admission to a hospital was to be diagnosed with a UTI or pneumonia caused by Legionella across the US under various climates and weather conditions. I found that patients were 10–20% more likely to have a UTI when the monthly mean temperature was between 65–85°F compared to under 40°F. This may be due to slightly lower levels of hydration at warm temperatures reducing protection against UTIs. Pneumonia caused by Legionella was more common in warm (60–80°F) months than in cool or hot months. Within warm months, when humidity was above 60% there was a doubling in the odds of Legionella pneumonia. When the humidity was above 65%, the odds were quadrupled. Understanding why some diseases are seasonal and what role weather plays in this seasonality is important for both daily practice (e.g., recent weather can help diagnosis Legionella versus a more typical cause of pneumonia) and for larger policy adapting to changing weather and climate.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 7 uppsatser.

Legionella pneumophila is a bacterium which can be found in fresh water and causes Legionnaires’ disease, which can be deadly for humans depending on the condition of the infected individual. The bacterium is a gram-negative rod and can withstand severe conditions such as high temperature. Therefore, various treatments including heat and acid treatment are performed on the water to inhibit interfering microorganisms. However, to examine a larger volume of water, the water needs to pass through a filter, which can be very time consuming, and there are various variables that have a negative impact on the filtration speed. The aim of this study was to examine these variables and find the fastest setup for detection of L. pneumophila. To filtrate the water, a manifold with funnels, where you put the water, is used, and the manifold is connected to a pump. Under the funnels, steel frits are placed, and the filter is placed on the steel frits. To examine the fastest setup, different manifolds, pumps, filters, and settings were investigated by timing the water running through in the different settings. A new way of sterilization, that does not damage the steel frits was tested, and the recovery of bacteria was examined on the filters with the top filtration speed. In conclusion, the most efficient setup is the Cyclopore (GE Healthcare Life Sciences) filter, the pump from KNF and the manifold MBS1 (Whatman), and the new way of sterilizing should be used to reduce the damage of the steel frits.

The severity of flood events is predicted to increase as a consequence of climate change and may lead to a higher burden of waterborne infectious diseases in the United States. Contaminated floodwater transports bacterial, protozoal, and viral pathogens that typically cause moderate intestinal or respiratory disease, but can also lead to more serious disseminated infections among immunocompromised, young, and older people. Hydroclimatology and drinking water infrastructure influence the transmission of disease, but their roles are not well-understood and may vary by pathogen-type or geographic region. Specific outbreaks of waterborne disease have been attributed to major floods and cases have been positively associated with some meteorological variables, but the association between infections and flooding has not been systematically examined. In this dissertation, we examine the association between seasonal and extreme floods and parasitic and bacterial infections using multiple flood-indicator variables and exposure definitions. In Chapter 2, we use multimodel inference and generalized linear mixed models to determine the effect of seasonal meteorology on hospitalizations across the US. We found that hospitalization rates were generally higher in rural areas and in places that relied on groundwater for drinking water sources. Soil moisture, precipitation, and runoff were associated with significant increases in hospitalizations for Legionnaires' disease, Cryptosporidiosis, and Campylobacteriosis, respectively. In Chapter 3, we use 23 years of weekly case data to examine the effect of cyclonic storms on six waterborne infections in a conditional quasi-Poisson statistical model. Storm exposure was defined separately for distinct storm hazards, namely wind speed and cumulative rainfall, and effects were examined over 3 weeks post-storm. We found that exposure to storm-related rainfall was associated with immediate and lagged increases in cases. In Chapter 4, we use a nonparametric bootstrap to examine the effect of anomalous meteorological conditions, i.e. extremes unrelated to cyclonic storms, on Legionnaires' disease hospitalizations. We also assess the effect of exposure to specific cyclonic storms in a GLMM framework and compare these approaches. Extreme precipitation and months with cyclonic storms were positively associated with Legionnaires' disease hospitalizations. Determining the effect of flooding on Legionnaires' disease is particularly important as it causes severe illness and has steadily increased in incidence for 20 years. An objective of this dissertation was to develop a framework for examining flood-disease dynamics in the context of hydrometeorological and infrastructure-related factors that may influence transmission. We demonstrated that drinking water source, rurality, and geography may play an important role in these dynamics; the analyses also underscored, however, the urgent need for more extensive epidemiological surveillance and water quality data. Climate change will likely place a considerable strain on aging water infrastructure in the US. A nuanced understanding of flood-disease dynamics is central to mitigating these effects.

Introdução: O diagnóstico microbiológico da infecção por Legionella é complexo, pois a bactéria não é visualizada à coloração de Gram no escarro, e sua cultura não é realizada na maioria dos laboratórios clínicos. A imunofluorescência direta nas secreções respiratórias tem baixa sensibilidade, em torno de 40% e a técnica da “PCR” não é ainda recomendada para o diagnóstico clínico (CDC, 1997). A detecção de anticorpos no soro é a técnica mais utilizada, e o critério definitivo é a soroconversão para no mínimo 1:128, cuja sensibilidade é de 70 a 80% (Edelstein, 1993). Como critérios diagnósticos de possível pneumonia por Legionella, eram utilizados: título único de anticorpos a L pneumophila positivo na diluição 1:256, em paciente com quadro clínico compatível (CDC, 1990) e o achado de antígeno a Legionella na urina (WHO, 1990). Nos últimos anos, porém, com o uso crescente do teste de antigenúria, foram detectados casos de pneumonia por Legionella, que não eram diagnosticados por cultura ou sorologia, tornando-o método diagnóstico de certeza para o diagnóstico de pneumonia por Legionella (CDC, 1997). Por sua fácil execução, resultado imediato, e alta sensibilidade - de 86% a 98% (Kashuba & Ballow, 1986; Harrison & Doshi, 2001), tem sido recomendado para o diagnóstico das PAC que necessitam internação hospitalar (Mulazimoglu & Yu, 2001; Gupta et al., 2001; Marrie, 2001), especialmente em UTI (ATS, 2001). Vários estudos documentaram baixo valor preditivo positivo do título único positivo de 1:256, tornando-o sem valor para o diagnóstico da pneumonia por Legionella, exceto, talvez, em surtos (Plouffe et al., 1995). Outros detectaram alta prevalência de anticorpos positivos na diluição 1:256 na população, em pessoas normais (Wilkinson et al., 1983; Nichol et al., 1991). A partir de 1996, o CDC de Atlanta recomendou que não seja mais utilizado o critério de caso provável de infecção por Legionella pneumophila por título único de fase convalescente ≥1:256, por falta de especificidade(CDC, 1997). A pneumonia por Legionella é raramente diagnosticada, e sua incidência é subestimada. Em estudos de PAC, a incidência da pneumonia por Legionella nos EUA, Europa, Israel e Austrália, foi estimada entre 1% a 16% (Muder & Yu, 2000). Nos EUA, foi estimado que cerca de 8 000 a 23 000 casos de PAC por Legionella ocorrem anualmente, em pacientes que requerem hospitalização (Marston et al., 1994 e 1977). No Brasil, a incidência de PAC causadas por Legionella em pacientes hospitalizados é tema de investigação pertinente, ainda não relatado na literatura. Objetivo: detectar a incidência de pneumonias causadas por Legionella pneumophila sorogrupos 1 a 6, em pacientes que internaram no Hospital de Clínicas de Porto Alegre por PAC, por um ano. Material e Métodos: o delineamento escolhido foi um estudo de coorte (de incidência), constituída por casos consecutivos de pneumonia adquirida na comunidade que internaram no HCPA de 19 de julho de 2000 a 18 de julho de 2001. Para a identificação dos casos, foram examinados diariamente o registro computadorizado das internações hospitalares, exceto as internações da pediatria e da obstetrícia, sendo selecionados todos os pacientes internados com o diagnóstico de pneumonia e de insuficiência respiratória aguda. Foram excluídos aqueles com menos de 18 anos ou mais de 80 anos; os procedentes de instituições, HIV-positivos, gestantes, pacientes restritos ao leito; e portadores de doença estrutural pulmonar ou traqueostomias. Foram excluídos os pacientes que tivessem tido alta hospitalar nos últimos 15 dias, e aqueles já incluídos no decorrer do estudo. Os pacientes selecionados foram examinados por um pesquisador, e incluídos para estudo se apresentassem infiltrado ao RX de tórax compatível com pneumonia, associado a pelo menos um dos sintomas respiratórios maiores (temperatura axilar > 37,8ºC, tosse ou escarro; ou dois sintomas menores (pleurisia, dispnéia, alteração do estado mental, sinais de consolidação à ausculta pulmonar, mais de 12 000 leucócitos/mm3). O estudo foi previamente aprovado pela Comissão de Ética em Pesquisa do HCPA. Os pacientes eram entrevistados por um pesquisador, dando seu consentimento por escrito, e então seus dados clínicos e laboratoriais eram registrados em protocolo individual. Não houve interferência do pesquisador, durante a internação, exceto pela coleta de urina e de sangue para exame laboratoriais específicos da pesquisa. Os pacientes eram agendados, no ambulatório de pesquisa, num prazo de 4 a 12 semanas após sua inclusão no estudo, quando realizavam nova coleta de sangue, RX de tórax de controle, e outros exames que se fizessem necessários para esclarecimento diagnóstico.Todos os pacientes foram acompanhados por 1 ano, após sua inclusão no estudo.Foram utilizadas a técnica de imunofluorescência indireta para detecção de anticorpos das classes IgG, IgM e IgA a Legionella pneumophila sorogrupos 1 a 6 no soro, em duas amostras, colhidas, respectivamente, na 1ª semana de internação e depois de 4 a 12 semanas; e a técnica imunológica por teste ELISA para a detecção do antígeno de Legionella pneumophila sorogrupo 1 na urina, colhida na primeira semana de internação. As urinas eram armazenadas, imediatamente após sua coleta, em freezer a –70ºC, e depois descongeladas e processadas em grupos de cerca de 20 amostras. A imunofluorescência foi feita no laboratório de doenças Infecciosas da Universidade de Louisville (KY, EUA), em amostras de soro da fase aguda e convalescente, a partir da diluição 1:8; e a detecção do antígeno de Legionella pneumophila sorogrupo 1, nas amostras de urina, foi realizada no laboratório de pesquisa do HCPA, pelos investigadores, utilizando um kit comercial de teste ELISA fabricado por Binax (Binax Legionella Urinary Enzyme Assay, Raritan, EUA). As urinas positivas eram recongeladas novamente, para serem enviadas para confirmação no mesmo laboratório americano, ao fim do estudo. Foram adotados como critérios definitivos de infecção por Legionella pneumophila sorogrupos 1 a 6, a soroconversão (elevação de 4 vezes no título de anticorpos séricos entre o soro da fase aguda e da fase convalescente para no mínimo 1:128); ou o achado de antígeno de L pneumophila sorogrupo 1 na urina não concentrada, numa razão superior a 3, conforme instruções do fabricante e da literatura.Os pacientes foram classificados, de acordo com suas características clínicas, em 1º) portadores de doenças crônicas (doenças pulmonares, cardíacas, diabete mellitus, hepatopatias e insuficiência renal); 2º) portadores de doenças subjacentes com imunossupressão; 3º) pacientes hígidos ou com outras doenças que não determinassem insuficiência orgânica. Imunossupressão foi definida como esplenectomia, ser portador de neoplasia hematológica, portador de doença auto-imune, ou de transplante; ou uso de medicação imunossupressora nas 4 semanas anteriores ao diagnóstico (Yu et al., 2002b); ou uso de prednisolona 10 mg/dia ou equivalente nos últimos 3 meses (Lim et al., 2001). As características clínicas e laboratoriais dos pacientes que evoluíram ao óbito por pneumonia foram comparados àquelas dos pacientes que obtiveram cura. Para a análise das variáveis categóricas, utilizou-se o teste qui-quadrado de Pearson ou teste exato de Fisher. Para as variáveis numéricas contínuas, utilizou-se o teste “t“ de Student. Um valor de p< 0,05 foi considerado como resultado estatisticamente significativo (programas SPSS, versão 10). Foi calculada a freqüência de mortes por pneumonia na população estudada, adotando-se a alta hospitalar como critério de cura. Foi calculada a incidência cumulativa para pneumonia por Legionella pneumophila sorogrupos 1 a 6, em um hospital geral, no período de 1 ano. Resultados: durante um ano de estudo foram examinados 645 registros de internação, nos quais constavam, como motivo de baixa hospitalar, o diagnóstico de pneumonia ou de insuficiência respiratória aguda; a maioria desses diagnósticos iniciais não foram confirmados. Desses 645 pacientes, foram incluídos no estudo 82 pacientes, nos quais os critérios clínicos ou radiológicos de pneumonia foram confirmados pelos pesquisadores. Durante o acompanhamento desses pacientes, porém, foram excluídos 23 pacientes por apresentarem outras patologias que mimetizavam pneumonia: DPOC agudizado (5), insuficiência cardíaca (3), tuberculose pulmonar (2), colagenose (1), fibrose pulmonar idiopática (1), edema pulmonar em paciente com cirrose (1), somente infecçâo respiratória em paciente com sequelas pulmonares (4); ou por apresentarem critérios de exclusão: bronquiectasias (4), HIV positivo (1), pneumatocele prévia (1). Ao final, foram estudados 59 pacientes com pneumonia adquirida na comunidade, sendo 20 do sexo feminino e 39 do sexo masculino, com idade entre 24 e 80 anos (média de 57,6 anos e desvio padrão de ±10,6). Tivemos 36 pacientes com doenças subjacentes classificadas como “doenças crônicas”, dos quais 18 pacientes apresentavam mais de uma co-morbidade, por ordem de prevalência: doenças pulmonares, cardíacas, diabete mellitus, hepatopatias e insuficiência renal; neoplasias ocorreram em 9 pacientes, sendo sólidas em 7 pacientes e hematológicas em 2. Dos 59 pacientes, 61% eram tabagistas e 16,9%, alcoolistas. Do total, 10 pacientes apresentavam imunossupressão. Dos demais 13 pacientes, somente um era previamente hígido, enquanto os outros apresentavam tabagismo, sinusite, anemia, HAS, gota, ou arterite de Takayasu. A apresentação radiológica inicial foi broncopneumonia em 59,3% dos casos; pneumonia alveolar ocorreu em 23,7% dos casos, enquanto ambos padrões ocorreram em 15,2% dos pacientes. Pneumonia intersticial ocorreu em somente um caso, enquanto broncopneumonia obstrutiva ocorreu em 5 pacientes (8,5%). Derrame pleural ocorreu em 22% dos casos, e em 21 pacientes (35%) houve comprometimento de mais de um lobo ao RX de tórax. Foram usados beta-lactâmicos para o tratamento da maioria dos pacientes (72,9%9). A segunda classe de antibióticos mais usados foi a das fluoroquinolonas respiratórias, que foram receitadas para 23 pacientes (39,0%), e em 3º lugar, os macrolídeos, usados por 11 pacientes (18,6%). Apenas 16 pacientes não usaram beta-lactâmicos, em sua maioria recebendo quinolonas ou macrolídeos. Dos 43 pacientes que usaram beta-lactâmicos, 25 não usaram nem macrolídeos, nem quinolonas. Em 13 pacientes as fluoroquinolonas respiratórias foram as únicas drogas usadas para o tratamento da pneumonia. Do total, 8 pacientes foram a óbito por pneumonia; em outros 3 pacientes, o óbito foi atribuído a neoplasia em estágio avançado. Dos 48 pacientes que obtiveram cura, 33 (68,7%) estavam vivos após 12 meses. Os resultados da comparação realizada evidenciaram tendência a maior mortalidade no sexo masculino e em pacientes com imunossupressão, porém essa associação não alcançou significância estatística. Os pacientes que usaram somente beta-lactâmicos não apresentaram maior mortalidade do que os pacientes que usaram beta-lactâmicos associados a outras classes de antibióticos ou somente outras classes de antibióticos. Examinando-se os pacientes que utiizaram macrolídeos ou quinolonas em seu regime de tratamento, isoladamente ou combinados a outros antibióticos, observou-se que também não houve diferença dos outros pacientes, quanto à mortalidade. Os pacientes com padrão radiológico de pneumonia alveolar tiveram maior mortalidade, e essa diferença apresentou uma significância limítrofe (p= 0,05). Nossa mortalidade (11,9%) foi similar à de Fang et al. (1990), em estudo clássico de 1991 (13,7%); foi também similar à média de mortalidade das PAC internadas não em UTI (12%), relatada pela ATS, no seu último consenso para o tratamento empírico das PAC (ATS, 2001). Foram detectados 3 pacientes com pneumonia por Legionella pneumophila sorogrupo 1 na população estudada: 2 foram diagnosticados por soroconversão e por antigenúria positiva, e o 3º foi diagnosticado somente pelo critério de antigenúria positiva, tendo sorologia negativa, como alguns autores (McWhinney et al., 2000). Dois pacientes com PAC por Legionella não responderam ao tratamento inicial com beta-lactâmicos, obtendo cura com levofloxacina; o 3º paciente foi tratado somente com betalactâmicos, obtendo cura. Conclusões: A incidência anual de PAC por Legionella pneumophila sorogrupos 1 a 6, no HCPA, foi de 5,1%, que representa a incidência anual de PAC por Legionella pneumophila sorogrupos 1 a 6 em um hospital geral universitário. Comentários e Perspectivas: Há necessidade de se empregar métodos diagnósticos específicos para o diagnóstico das pneumonias por Legionella em nosso meio, como a cultura, a sorologia com detecção de todas as classes de anticorpos, e a detecção do antígeno urinário, pois somente com o uso simultâneo de técnicas complementares pode-se detectar a incidência real de pneumonias causadas tanto por Legionella pneumophila, como por outras espécies. A detecção do antígeno de Legionella na urina é o teste diagnóstico de maior rendimento, sendo recomendado seu uso em todas as PAC que necessitarem internação hospitalar (Mulazimoglu & Yu, 2001; Gupta et al., 2001); em todos os pacientes com PAC que apresentarem fatores de risco potenciais para legionelose (Marrie, 2001); e para o diagnóstico etiológico das pneumonias graves (ATS, 2001). Seu uso é indicado, com unanimidade na literatura, para a pesquisa de legionelose nosocomial e de surtos de legionelose na comunidade. / Introduction: Legionella infections are difficult to diagnose, because the bacteria is not seen at Gram stain and the sputum culture is not performed at most laboratories. Besides that, the direct fluorescent fluorescent antibody test of respiratory secretion has low sensitivity (40%) and detection by PCR techiques is still not recommended for clinical diagnosis (CDC, 1997). The most used test is antibody detection by immunofluorescence technique or by ELISA, with a demonstration of fourfold or greater rise in the reciprocal immunofluorescente antibody (IFA) titer to greater than or equal to 1:128 against Legionella pneumophila serogroup 1 between paired acute-and convalescent-phase serum specimens, which sensitivity ranges between 70 - 80% (Edelstein, 1993).Case definitions for Legionnaires´disease agreed that patients with pneumonia who have positive results in urinary antigen assays or positive results in the direct fluorescent antibody (DFA) staining of respiratory secretions, had “probable” or presumptive” disease (WHO; 1990), as well as those who have single antibody titers of ≥1:256 (CDC, 1990). The Legionella urinary antigen test have been increasingly used in the last years, showing patients with positive results despite of negative culture tests or non-diagnostic serologies. Since then, the urinary antigen test has became a valuable tool in the prompt diagnosis of Legionnaires´disease, and also a definitive criterion for the diagnosis of Legionella pneumonias (CDC, 1997). Due to its high sensitivity, in the range of 86% to 98% (Kashubba & Ballow, 1986; Harrison & Doshi, 2001), it has been recommended to the diagnosis of community-acquired pneumonia which requires hospitalization (Mulazimoglu & Yu, 2001; Gupta et al, 2001), mainly in the ICU (ATS, 2001). Concerning to the “presumptive” criterion of single antibody title of 1:256, in the absence of seroconversion, it was concluded that it shall not be used except in the outbreak setting, since it has been reported to have low predictive value (Plouffe et al, 1995); and has also low specificity (CDC, 1997), since it has been reported high prevalence of positive antibodies at 1:256 in healthy populations (Wilkinson et al, 1983; Nichol et al, 1991). Legionnaires´disease is markedly undiagnosed, either its incidence underestimated. In several studies of CAP conducted in the USA, Europe, Israel and Australia the proportion of pneumonias caused by Legionella has ranged from 1% to 16% (Muder & Yu, 2000). In USA, the incidence of Legionella CAP in patients requiring hospitalization is estimated between 8000 to 23 000 cases per year (Marston et al, 1994 ; Marston et al, 1997). Such incidence in Brazil has not yet been estimated, being an important issue to study Objective : our goal is to detect the incidence of Legionella CAP in patients requiring hospitalization for a year, at the HCPA. Material and Methods: a cohort study ( an incidence study) of adult patients with CAP who were hospitalized for one year ( from 2000-2001) at HCPA. All patients with age 18≥80 were screened for study entry except: residents in institutions, those disabled to walk, those who had been discharged from hospital in the last 15 days; either pregnant women, HIV-positives, or patients with estructural lung diseases (bronchiectasis, cistic fibrosis) or tracheostomized. Admission logs were screened daily from Monday trough Friday (including the ones who had been hospitalized in the week-end) by the researchers. Patients with an admission diagnosis either of pneumonia or acute respiratory failure were evaluated daily by the researchers, and enrolled if they had a Chest X-Ray taken within 48 hours of admission revealing a new infiltrate consistent with pneumonia and at least 1 of the following “ major criteria” : fever (axillary temperature ≥37,8ºC), cough, or sputum; or 2 of the following “minor criteria”: dyspnea, abnormal mental status, signs of consolidation by examination, pleuritic chest pain or abnormal white blood cell count (> 12.000/cm3 or band forms > 4 % ). Information about risk factors, symptoms and outcome was collected through interview and medical chart review. Urine and serum samples were collected from consenting individuals during the acute fase at the hospital. After discharge, they came to the research ambulatory to consultation 4 to 12 weeks after patient enrollment, when the research doctor asked a new Chest X-Ray and serum sample of the convalescent phase to antibody test, along with other necessary exams. All the survivors were followed for a whole year after their inclusion in the study. Acute and convalescent sera were stored at – 70ºC and sent in dry ice (in a “batch”) to the Infectious Diseases laboratory of University of Louisville ( KY, USA), where they were tested by indirect immunofluorescent assay to IgG, IgM, and IgA antibodies to L pneumophila serogroups1-6, starting at dilution of 1:8. It was used a kit test manufactured by Zeus Scientific, Inc (Raritan, NJ, USA). All the urine samples collected were immediately frozen at –70ºC to be further tested in batches, at the Research lab of HCPA, by the investigators, with a commercial EIA kit test manufactured by Binax (BINAX Legionella Urinary Enzyme Assay). The positive ones were refrozen and further sent in a “batch” to the American laboratory, to be retested by the same kit test. Patients were diagnosed as having definite infection by L pneumophila serogroups 1-6 either if they had a 4-fold rise in antibody titer to at least 1:128 or greater dilution; or if they had positive urinary antigen, performed at our lab as recommended by the manfacturer and by the literature. A comparison was made between the patients who died and the survivors, regarding his clinical and laboratory features. Testing procedures to detect significant differences between groups included the Pearson chi-squared test or Fisher exact tests for categorical variables and Student´s t-test for continuous variables. Associations were considered statistically significant if the p value was < 0,05, using a 2-tailed test (SPSS program, version 10). Death by pneumonia was definite as the patient who died primarily due to the worsening of his lung sickness; thus, was calculated the frequency of deaths in our population. Patients who improved and were discharged, were classified as “cured”. Finally, we calculated the cumulative incidence of CAP caused by Legionella pneumophila serogroups 1-6 in a general hospital, for a year. Results: during a whole year, from 645 hospital admission logs with the diagnosis of pneumonia or acute respiratory failure screened, only 82 cases of CAP were obtained. During the follow up in the hospital or ambulatory, 23 patients were excluded either because Chest X-Ray failed to show a new pulmonary infiltrate (5 patients), alternative diagnosis were made (COPD, 5 patients; heart failure, 3; tuberculosis, 2; colagenosis, 1; idiopathic pulmonary fibrosis, 1). Aditional 6 patients revealed exclusion criteria as being HIV positive (1 patient), to have bronchiectasis (4) or pneumatocele (1). Thus, 59 patients constituted the final study group, being each patient enrolled only once. The mean age was 57,6 years (ranging from 24 to 80), being 20 women and 39 men. Most of them ( 36 patients, 61%) had chronic underlying diseases; half of them had more than one disease, being more prevalent: lung diseases, heart diseases, diabete mellitus, liver diseases and renal failure. Regular cigarette smokers represented 61% of the total, and alcohhol intake, 16,9%. Cancer ocurred in 9 patients, being solid organ malignancy in 7 and haematologic malignancy in 2. From our 59 patients, 10 were classified as immunossupressed, defined as splenectomy, haematological malignancy, autoimmune disease, transplant recipient, cancer chemotherapy within 4 weeks (Yu et al, 2002), or prednisolone use ≥10 mg/day (or equivalent), for at least 3 months before admission (LIM et al, 2001). In the remaining 13 patients, only one was previously healthy, while the others had sinusitis, anemia, hypertension, or other mild diseases. At admission, Chest X-Ray showed intersticial pneumonia in only one patient; bronchopneumonia in 59,3% and airspace pneumonia in 23,7%, while both patterns ocurred concomitantly in 15,2%. Obstructive pneumonia (Fang et al, 1990) ocurred in 5 patients with lung cancer. Pleural effusion ocurred in 22%, and in 21 patients (35%) the presentation was multilobar.The antibiotic class most used were beta-lactams, in 72,9% of the patients. The remaining received at most respiratory quinolones and macrolides. From the group that used beta-lactams, 25 patients did not use either quinolones or macrolides.There were not statistic differences in mortality regarding age, sex, or treatment between the groups who received beta-lactams alone versus the group that received macrolides or respiratory quinolones. The only significant association ocurred between radiographic pattern of airspace pneumonia and greater mortality (p= 0,05). In this study 3 patients had pneumonia caused by Legionella pneumophila serogroup 1: 2 patients had seroconversion and positive antigen urinary test; the third patient had a positive urinary antigen with negative serologies, like some authors (McWHINNEY et al, 2000). The former two patients worsened with beta-lactams, prescribed before the etiological diagnosis, getting resolution of their pneumonia with levofloxacin; the third one used only beta-lactams, getting cure. There were 7 deaths for pneumonia, and 4 deaths for cancer. From 48 survivors, 33 patients (68,7%) were alive after 12 months. Our mortality rate (13,5%) is similar to the one reported in the literature (ATS, 2001). Conclusions: the incidence of hospitalized CAP by Legionella pneumophila serogroups 1-6 in our hospital in the year 2000-2001 was 5,1%, which represents the annual incidence of Legionnaires´ disease in a general hospital of South Brazil. Comments and perspectives: complementary diagnostic methods like culture, serologies to detection of all classes of immunoglobulins and urinary antigen tests shall be used to detect infections by Legionella in our country to detect the real incidence of pneumonias caused by Legionella species. At the moment, the Legionella antigen test has the greatest yeld among the available tests. It is recommended to all hospitalized PAC patients (Mulazimoglu &Yu, 2001; Gupta et al, 2001); and also to all patients who have potential risk factors for legionellosis (Marrie, 2001), as well as to the etiological diagnosis of severe pneumonias (ATS, 2001). Its use is recommended, with unanimity, to the diagnosis of community and nosocomial outbreaks.