Dissertations / Theses on the topic 'Legionnaires' disease'

A prospective study of patients with pneumonia admitted to Groote Schuur Hospital took place over a one-year period in an attempt to assess the incidence of legionella pneumonia. Acute and convalescent serum samples were obtained from 113 patients. Eight patients (7,1%) showed a fourfold rise in antibody titre against Legionella pneumophila group 1 antigen by indirect immunofluorescent test (IFAT). The findings suggest that legionella pneumonia, although not common, should be considered in the aetiology of pneumonia at Groote Schuur Hospital. The results are presented and a review of the literature is undertaken.

Bibliography: leaves 246-304. Describes experiments aimed at characterising the potential virilant factors of Legionella longbeachae sg 1, an important human pathogen which is responsible for nearly half of all clinical cases of Legionella related pneumonia reported each year.

The major sources of infection for Legionnaire's Disease, identified by study of outbreaks, are hot water systems and cooling towers. However, most cases are not part of outbreaks and, for these, the source of infection is rarely traced. The principal aim of this study was to help understand the source of non-outbreak infection by examining the epidemiology of the disease in Scotland. Of the recognized cases which met the study case-definition, 366 were ill between 1978 to 1986 giving a mean annual incidence rate of 7.9 per million. The annual incidence varied in Scotland (range 3.1 to 20.2) and within health boards. Geographical variations were demonstrated by health board, by city and within cities, particularly for non-travel infection. For example, the cumulative incidence rate per million for non-travel, non-outbreak disease in Greater Glasgow Health Board (GGHB) was 130 compared to 45 for the whole of Scotland, and 11, 33 and 50 in Tayside, Lanarkshire and Lothian Health Boards respectively. Of 16 postcode sectors with a high incidence of disease in Scotland, 14 were in GGHB. In GGHB, the residence of non-travel, non-outbreakcases (but not of travel-related ones) was clustered in central areas. Previously unrecognised clustering was also found in other health boards. These variations were not fully explained by differences in the population's exposure to diagnostic tests, as indicated by the number of serology tests requested by Scottish hospitals; the diagnostic service and approach of bacteriology laboratories; and the approach of hospital consultants to the diagnosis of Legionnaires' Disease. Differences in host susceptibility, as reflected by socio-economic status and the incidence of other respiratory disease, were small and did not explain the variation. In the City of Glasgow, many cooling towers were not maintained in accord with recommendations and posed a theoretical risk of infection. The location of residence of non-travel cases was associated with the location of premises with cooling towers, the incidence of non-travel Legionnaires' Disease being more than three times higher in areas of Glasgow within 0.5 kilometres of a cooling tower than in areas more than one kilometre away. The best explanation for these observations is that cooling towers were a major source of non-travel, non-outbreak infection. Hence, for the investigation and prevention of such infection, the emphasis should be on cooling tower maintenance. Close surveillance of apparently sporadic disease is recommended as the basis for disease control and future research.

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.

A virulent strain of Legionella pneumophila serogroup 1 was established in continuous culture under defined iron-replete conditions at pH 6.9. Iron-limitation and extremes of pH (6.0 and 7.8) influenced the growth and metabolism of L. pneumophila, as manifested by increased metabolic activity, impaired energy coupling, and altered metabolic fluxes. In particular, the physiological versatility of L. pneumophila was demonstrated by a significant decrease in the iron content of biomass (6-fold increase in Yiron), coupled with reduced metabolic efficiency (Y, on), in response to iron-limited growth. Iron limitation promoted the accumulation of significant intracellular reserves of poly- ß-hydroxybutyrate (16 % cell dry wt.), which supported long-term survival of L. pneumophila under starvation conditions. Expression of the important pathogenicity factor, the zinc metalloprotease, was regulated by iron availability. Common iron acquisition mechanisms, such as siderophores and transferrin receptors, were not elaborated by iron-limited cells. However, human transferrin was identified as a potential iron source for L. pneumophila, with the zinc metalloprotease mediating transferrin digestion and possibly iron acquisition. Iron-limitation and extremes of pH also influenced cellular morphology and the surface properties of L. pneumophila, promoting the formation of uniform cultures of short rod-shaped bacteria, with altered fatty acid, phospholipid and protein composition. In addition to morphological and physiological adaptation, iron limitation had a significant effect on the virulence of L. pneumophila. Iron-replete cells grown at pH 6.9 and 6.0 were highly virulent in a guinea pig model. However, the virulence of L. pneumophila was significantly attenuated (P < 0.05) in response to iron-limited growth. This phenomenon was reversible, and correlated with reduced phagocytosis and / or reduced intracellular survival following infection. Decreasing the pH of iron-limited cultures to 6.0 did not stimulate recovery of culture virulence. Therefore, this study clearly demonstrates that environmental stresses, including iron limitation and extremes of pH, play an important role in modulating the physiology and virulence of L. pneumophila, inducing the expression of distinct phenotypes differing in their ability to persist in nature and cause infection.

Background. Legionnaires’ Disease (LD) is a mild to severe, potentially lethal, respiratory syndrome caused by members of the Legionella genus, in particular L. pneumophila serogroup (sg) 1 alone causes about 95% of culture confirmed cases. The infection is usually acquired by inhalation of aerosols originating from contaminated fresh water sources, consequently typing of both clinical and environmental isolates is crucial to rapidly identify the possible source and prevent further cases. Legionellae are difficult to isolate by culture, moreover as respiratory samples are not available for up to 65% patients, alternative techniques are needed to diagnose LD and maximise the amount of typing data that can be obtained to aid investigations. Urinary antigen detection and serology provide very limited information regarding the infecting strain, while the advent of PCR and Sanger sequencing has allowed reliable diagnostic and typing methods to be introduced. Objectives. The aim of this study was to improve existing diagnostic and typing molecular assays, and to develop new ones to further standardise diagnostic and typing procedures across members of the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Legionella Infections (ESGLI). Utility of the assays was assessed in both routine and outbreak scenarios. Methods. A wide range of both in silico and in vitro experiments were used to design and validate specific oligonucleotides to improve detection and typing of L. pneumophila. Genomic DNA was manually extracted and prepared for Whole Genome Sequencing (WGS) using Illumina platforms. A bioinformatic approach was used to design a WGS based typing scheme and decipher the evolution of L. pneumophila sg1 Sequence Type (ST) 47, a major disease-causing strain. Results. A real-time PCR detecting L. pneumophila and sg1 specific targets was validated with international colleagues and made available to ESGLI members. Sequence based typing was improved and expanded, and specific typing guidelines produced. A 50 gene core-genome MLST was identified as the best approach to improve the current typing method. ST47 was shown to be a ‘chimera’ between ST109 and ST62, and a specific real-time PCR was designed to detect this strain. Conclusions. The results of this study allowed researchers to obtain faster and more accurate diagnosis of LD, and L. pneumophila typing data from both isolates and primary samples. A metagenomics approach is presently under evaluation to obtain typing results by WGS directly from clinical and environmental samples.

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.

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.

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.

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.

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.

A doença dos legionários consiste em uma broncopneumonia severa e atípica, que acomete de 2 a 7% das pessoas infectadas com Legionella spp e que apresenta taxa de mortalidade que varia de 5 a 30%, sendo considerada uma importante causa de morbidade e mortalidade mundial. A patologia causada pela espécie L. pneumophila tem sido amplamente estudada em modelos experimentais e suas características clínicas foram extensivamente descritas. No entanto, este modelo não representa adequadamente a doença que acomete seres humanos, pois L. pneumophila não é letal aos camundongos como é para humanos. Recentemente, uma nova espécie de bactéria do gênero Legionella, denominada Legionella longbeachae, foi descrita como importante agente de doença dos legionários em países do hemisfério sul. A pneumonia induzida por L. longbeachae em humanos não difere da induzida por L. pneumophila. No entanto, L. longbeachae é letal para camundongos em doses baixas, o que torna esse modelo murino de doença dos legionários mais fidedigno ao que ocorre com humanos. Com a acentuada mudança dos hábitos de nossa sociedade, há o aumento do número de pessoas com fatores que predispõe a doença, como idade elevada ou tratamento imunossupressor. Assim, entender melhor a relação patógeno-hospedeiro no curso da doença dos legionários por meio da utilização de um modelo experimental adequado é importante para a descoberta de novos meios de combater este patógeno. Neste trabalho, geramos uma cepa de L. longbeachae mutante para rpsL, que se torna resistente à estreptomicina. Essa cepa pode ser utilizada para infecções in vivo nas quais a quantificação da CFU foi estimada em placas contendo antibiótico, o que culmina em maior eficiência experimental e menor quantidade de contaminações. Essa cepa foi utilizada em experimentos in vivo para avaliar os componentes do sistema imune que operam na resistência diante de uma dose letal bacteriana administrada pela via intranasal. Demonstramos que camundongos deficientes para as citocinas IFN ou TNF e para o receptor de quimiocinas CCR2 são mais susceptíveis à infecção do que os camundongos selvagens. No entanto, camundongos deficientes para o receptor de quimiocinas CCR5, para o receptor de IL-17, para a citocina IL-6 ou para o receptor citoplasmático NOD2 são mais resistentes à infecção quando comparados com animais selvagens. A descoberta destas moléculas em um modelo de infecção letal in vivo ressalta a importância de alguns componentes da imunidade para a resistência durante a doença dos legionários experimental e possíveis alvos terapêuticos para essa doença.
Legionnaires disease is a severe and atypical bronchopneumonia, which affects 2-7% people infected with Legionella spp and has a mortality rate of 5 to 30%, therefore it is considered an important cause of mortality and morbidity worldwide. Disease caused by Legionella pneumophila has been largely studied in experimental models and its clinical characteristics was extensively described. However this model does not adequately represent the disease that affects humans, because L. pneumophila is not lethal to mice, as it is to humans. Recently, a new species of bacterium from Legionella genus, called Legionella longbeachae, was described as an important agent of Legionnaires disease in the southern hemisphere. The pneumonia induced by L. longbeachae in humans is not different from pneumonia induced by L. pneumophila. However, a low dose of L. longbeachae is lethal to mice, which makes this murine infection model of Legionnaires disease more reliable than that which occurs in humans. Because our society is changing, there is an increase in the number of persons with predisposing factors, like higher age or immunosuppressive treatment. So, a better understanding of host-pathogen relationship by using a suitable experimental model is important to find new ways to fight this pathogen. Here, we generated a strain of rpsL mutant L. longbeachae, which becomes resistant to streptomycin. This strain could be used in in vivo infections, when CFU quantification was estimated in plates with antibiotic, culminating in greater experimental efficiency and lower contamination. This strain was used in in vivo experiments to evaluate components of the immune system that participates in resistance against lethal dose of bacteria administered intranasally. We showed that Tnf-/-, Ifn-/- or Ccr2-/- mice are more susceptible to infection than wild type mice. However Ccr5-/-, Il17r-/-, Il6-/- or Nod2-/- mice are more resistant to infection than wild type animals. The discovery of these molecules in a lethal infection model in vivo highlights the importance of some components of immunity to resistance during experimental Legionnaires disease and potential therapeutic targets to disease.

Trabalho apresentado à Universidade Fernando Pessoa como parte dos requisitos para a obtenção do grau de Licenciado em Ciências Farmacêuticas
A Doença dos Legionários é uma forma de pneumonia atípica causada pela bactéria Legionella pneumophila. O período de incubação é de dois a dez dias, após o que surge uma pneumonia multifocal necrotizante com a formação de microabcessos. Os sintomas incluem, febre, tremores, tosse seca e dores de cabeça. As Legionellas encontram-se frequentemente em reservatórios de água e crescem em água quente. Os sistemas de distribuição de água e reservatórios são identificados como as principais fontes de infecção em muitos dos artigos de investigação. Embora a Doença dos Legionários possa ocorrer em qualquer idade, os indivíduos de meia-idade e os idosos são os mais frequentemente afectados. Os tabagistas, os etilistas ou aqueles que fazem uso de corticosteróides parecem apresentar um maior risco. A taxa de mortalidade é muito mais elevada entre os indivíduos que contraem a doença em hospitais (PAC) ou que apresentam imunodeficiência, estando em torno de 20% nos demais grupos. O objectivo do estudo que se desenvolve nas páginas seguintes pretende contribuir para uma melhor compreensão e conhecimento do género Legionella. Foi feita uma pesquisa com enfoque na etiologia, patógenese, manifestações clínicas, diagnóstico laboratorial, tratamento, prevenção e epidemiologia. Legionnaires’ Disease is a form of atypical pneumonia caused by the bacterium Legionella pneumophila. The incubation period is from two to ten days, after which comes a multifocal necrotizing pneumonia with the formation of microabscesses. The symptoms include fever, chills, dry cough and headaches. The Legionella are often found in water tanks and grow in hot water. The water distribution systems and reservoirs are identified as major sources of infection in many of the research papers. Although Legionnaires’ Disease can occur at any age, individuals of middle-aged and elderly are the most often affected. The smokers, alcoholics or those that make use of corticosteroids appear to be at greater risk. The mortality rate is much higher among individuals who contract the disease in hospitals (PAC) or who have immunodeficiency, which is roughly 20% in other groups. The aim of this study that develops in the following pages is to contribute to a better understanding and knowledge of the Legionella genus. A search was made having as focus, the etiology, pathogenesis, clinical manifestations, laboratory diagnosis, treatment, prevention and epidemiology.

Legionella pneumophila, the causative agent of Legionnaires' disease, is a water born pathogenic bacteria commonly found in natural and manmade water systems such as rivers, lakes, wet soil, hot and cold water storage systems (being able to survive at temperatures between 6-63 °C, and proliferating between 20-45 °C), showerheads, cooling towers and spa pools. The main pathway of exposure to Legionella is by inhaling the aerosols containing the microorganism. Legionnaires' disease can be fatal if not diagnosed and treated at the right time. Practical Legionella control starts with a risk assessment of the water system and followed by the regular monitoring and water sampling. UK Health and Safety Executive (HSE) have implemented strict legislations to protect the public from Legionnaires' disease. This research highlights and addresses three major data gaps identified in Legionella control and management strategy employed in the UK and worldwide; namely, (i) the underestimation of microbiological threat in current cold water storage sampling strategy, (ii) the inability of current qPCR diagnostic methods to detect live Legionella in water samples, and (iii) the lack of predictive 'risk management system' for Legionella control in domestic water systems. During my PhD, 15 relevant cold water storage tanks (selected from more than 6000 tanks surveyed at different sites located in different London Boroughs) were used to investigate the risk factors that contribute towards Legionella proliferation, and revealed serious shortcomings in the appropriateness of the water sample taken for regulatory testing. Secondly, molecular biology research was carried out to develop an accurate, reliable and rapid testing method for the detection and quantification of live Legionella using qPCR techniques. This was successfully achieved by extracting RNA from a Legionella lenticule, converting the RNA into cDNA and amplifying the cDNA using qPCR techniques. Finally, regular monitoring data from 120 London buildings (60 known to be Legionella positive and 60 known to be Legionella negative) was used to identify the possible risk factors contributing towards Legionella outbreaks. Data for these factors was then used to develop a predictive risk model for Legionella contamination using Principal Component Analysis (PCA). The model was validated with 66 new London buildings and 9 out of London buildings. The model showed 100% accuracy in predicting the risk of Legionella by distinguishing infected and non-infected sites in London as well as for the sites in out of London.

Legionella pneumophila, the causative agent of Legionnaires' disease, is an aquatic intracellular organism capable of replicating within both amoebae and human phagocytic cells. A comprehensive study has been undertaken to examine the hypothesis that intracellular replication of L. pneumophila induces enhanced resistance to external stress stimuli relative to that of in vitro grown legionellae. Microscopical studies have shown that L. pneumophila grown in YE broth consistently develop a rod-shaped morphology and are non-motile. In contrast, L. pneumophila grown within Acanthamoeba polyphaga or U937 monocytes exhibit a smaller, rounded morphology and are highly motile. After ca. 72 h post lysis, the intracellular bacteria adopted a morphology similar to that of broth grown legionellae in stationary phase. These bacteria were termed 'aged'. Time-kill assays have shown that L. pneumophila grown within A. polyphaga or U937 monocytes are more resistant than broth grown legionellae to a number of different stress conditions including exposure to the antibiotics traditionally used in the treatment of Legionnaires' disease, elevated temperatures associated with water treatment processes, mechanical stress and starvation. 'Ageing' of intracellular L. pneumophila before exposure to the stress stimuli, resulted in a marked loss of stress resistance. To study the physiological basis of the increased stress resistance of intracellular grown L. pneumophila, a preliminary study of the surface properties of the variously grown legionellae was undertaken. The outer membrane protein (OMP) profiles of the L. pneumophila were prepared using sarkosyl and analysed by SDS-PAGE. Proteinase K digestion of the outer membrane (OM) was employed to prepare the LPS layer. The preliminary comparative study of the L. pneumophila OM has established that the mode of growth influences both the OMP profile and the LPS layer. In particular, intra-amoebic grown L. pneumophila possesses a novel protein of 15 kDa and intra-monocytic grown legionellae one of 24 kDa, both of which are lost upon 'ageing'.The results of the project have shown a link between the presence of novel sarkosyl insoluble OMPs, bacterial morphology and enhanced resistance of the intracellular grown L. pneumophila to external stress stimuli. It could, therefore, be suggested that L. pneumophila undergo a prior adaptation to stress conditions during intracellular replication. Upon 'ageing' of intracellular grown legionellae the novel insoluble OMPs were lost with a concomitant change in morphology and loss in resistance to external stress stimuli. The findings of this work have practical implications with respect to the clinical treatment of Legionnaires' disease and the eradication of the causative agent from water systems.

The attachment and/or penetration of animal cells by two strains of Legionella pneumophila was studied in three vertebrae cell lines in vitro . The study focused on (1) differences in attachment and penetration between the two bacterial strains (an environmental isolate, Johannesburg-2, and a clinical isolate, Chicago-8) and between the cell lines (Hep-2, WI-38 and a murine line); (2) effects of L. pneumophila on cell morphology and growth; and (3) the effects of pyruvate and six sugars or sugar derivatives (D-mannose, D-Galactose, D-Glucose, L-glucose, D-fructose, and 2-deoxy-D-glucose).

Outer membrane proteins (OMPs) were recovered from eleven strains (eight serogroups) of Legionella pneumophila by sequential treatment with Tris buffer (pH 8), citrate buffer(pH 2.75) and Tris buffer (pH 8). Transmission electron microscopy revealed clearly the separation of the outer membrane from the bacteria. The development of delayed hypersensitivity was also noted by measuring the area of arythema and induration produced by intradermal injections of the MPSs from Chicago 8 strain. The adjuvants enhanced greatly both active and cell-meditated immunity (CMI). Transient lymphocytopenia with a slight rise in neutrophils was noted in each of the immunized groups. Intraperitoneal challenge, seven days after the OMP booster, of one LD (1.5 x10^6) of legionellae resulted in lymphocytopenia with elevated neutrophils. All immunized rats survived the challenge, although those in the saline-OMP group were clearly the sickest. Post-challenge, legionella antibody titers rose greatly and CMI was heightened. Passive immunization (homologous and heterologous) was found to protect the rats from a challenge of on LD. Actively-immunized rats retained their immunity for at least six months as determined by their resistance to a second challenge.

Legionella pneumophila is a gram-negative bacterium responsible for Legionnaire's disease, and is commonly transmitted via aerosolized water. Legionella colonization of emergency eyewash and shower stations may pose an exposure hazard to users of these stations. There is little information about the role of these stations as significant reservoirs for Legionella. Samples were collected from 67 stations in an industrial facility. At the time of this study, the stations within this facility were under a routine maintenance program that included at least monthly flushing. This study also included the analysis for other bacterial organisms to determine an association between the presence and concentration of other bacteria and Legionella. All samples resulted in no detection of Legionella, yet 12 of the samples contained large counts of other bacteria. Thus, this study supports that properly maintained emergency eyewash and shower stations do not appear to be a significant source for aerosol transmission of Legionella.

Background Legionnaires’ Disease (LD) has been recognized as a significant source of morbidity and mortality in many hospitals worldwide. Legionella in the hospital water distribution system has been epidemiologically linked to hospital-acquired LD. Despite the several disinfection methods available the optimal method to control hospital-acquired LD has not been established yet. Objectives To assess the efficacy of interventions for preventing hospital-acquired LD in hospitalized patients at high risk of developing the disease and the effect on environmental colonization associated to the risk of developing hospital-acquired LD. Search Methods We searched The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library and MEDLINE (PubMed). We also handsearched the reference lists of all primary studies identified by the initial search. Selection Criteria All controlled studies investigating the efficacy of interventions for the prevention of hospital-acquired LD, in hospitalized patients at high-risk for developing LD, were eligible for inclusion. Data collection and analysis Two authors independently assessed the trials and extracted data. Data was analysed using statistical software, Review Manager 5.2. Results Three controlled trials, two assessing copper-silver ionization and one assessing ultraviolet light (UVL), met the inclusion criteria. The meta-analysis showed a significant benefit in using copper-silver ionization rather than no intervention for Legionella positivity in distal sites, with RR = 0.04 (95% CI Fixed Effects 0.001, 0.29). One study demonstrated benefit of UVL versus no intervention with a RR = 0.03 (95% CI 0.00, 0.41) for Legionella positivity in water samples. Authors’ conclusions Our review demonstrates that copper-silver ionization and UVL are beneficial, compared with no treatment, to prevent hospital-acquired LD. However the quality of the body of evidence identified does not allow a robust conclusion regarding the effectiveness of interventions for preventing hospital-acquired LD. Further research with well design and high quality studies is needed.

Background Legionellosis are infections caused by Legionella spp. The diagnosis of high-risk patients should rely on microbiological tests which allow the establishment of this infection etiology. Cases have to be confirmed through the available diagnostic methods which have different performances, sensitivity, specificity, error causes, limitations, and needs of careful interpretation. Objectives Assess the accuracy of urinary antigen detection, direct fluorescent antibody (DFA) staining, serological testing, Protein Chain Reaction (PCR) versus culture (reference standard), in patients suspected to be infected with Leggionella or patients with laboratory confirmed Legionnaire Disease (LD). Search Methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library and MEDLINE (PubMed). We also handsearched the reference lists of the included studies. Selection criteria Observational studies were included, comparing the index tests with culture in patients suspected to be infected with Legionella or patients with laboratory confirmed LD. Data collection and analysis Two authors independently assessed the trials and extracted data. Data was analysed using statistical software Review Manager 5.1. Main results Five studies met the inclusion criteria. All studies evaluated PCR and DFA tests to detect Legionella in clinical specimens, comparing it with culture (reference standard) and were included in meta-analysis. PCR sensitivity and specificity ranged from 56% to 100% and from 89% to 100%, respectively. The pooled sensitivity was 74% (95% IC 67%-80%), and the specificity 97% (95%IC 96%-80%). DFA sensitivity varied from 33% to 44% and the specificity from 100% the pooled sensitivity was 40% (95% IC 21%-61%) and the specificity 100% (95% IC 81%-100%). Author´s conclusions This review demonstrates that PCR have a high sensitivity and specificity for early diagnosis of LD. However standardization is required for biological samples. Although this, culture is always required for epidemiological studies, strains molecular typing and antibiotic sensibility evaluations if needed

碩士
國立中興大學
環境工程學系所
101
This study is to investigate the knowledge, attitude and behavior of Legionnaires''disease for staffs working in environmental safety health department, infective control department and other relevant units of six hospitals in central Taiwan. In total of 400 questionnaires, 360 were returned, and fill out answers not completely questionnaire as invalid questionnaires, we finally have 341 valid questionnaires, and the effective rate was 85.3%. We use Legionnaires'' disease Attitude Scale internal consistency analyze(criterion of internal consistency) the reliability. The results of Legionnaires'' disease Attitude form showed that the Cronbach''s α value is 0.835. The collected data is analyzed the descriptive statistics, t-test, F-test and multiple regression by R software To verity the elationship between knowledge, attitude and behavior of Legionnaires'' disease for the different levels of hospital staffs and to identify the reasons for the difference of Legionnaires'' disease behavior scores. Based on the the analysis of statistical results, the following is this study conclusions: 1. In Legionnaires'' Disease cognitive, the hospital (F) is the highest average score of 7.05 Points. in percentage of correct, the question for control the biological characteristics of the operating guidelines is better, but for control of disinfection topic in the operational guidelines is poor percentage of correct, result show the cognitive of staff Legionnaires''disease disinfection methods is lacking, hospitals should strengthen knowledge of the staff for Legionnaires'' disease disinfection methods. 2. In Legionnaires'' disease attitude, the hospital (F) is the highest average score of 3.06 points, the highest score of the question is "I think the special hospital environment, the staff have to regular take the health examination" that score is 3.47 points, the lowest score of the question is "I think the Legionnaires'' disease is not contagious between people " the score is 2.28 points. Showing the uncertainty for the staff of the hospital for the Legionnaires'' disease Whether human- to-human transmission of the infection process or not, and they think that as long as taking the infection control training in regularly and the health and safety in working should not be a problem, but if anyone infected with Legionnaires'' disease that will be felt very reluctant about it. 3. In Legionnaires ''disease behavior, the hospital (B) is the lowest average score of 2.69 points, the highest score of the question is "Legionnaires'' disease infection control training is boring, I do not want to join" that is score is 3.14 points, the lowest score is "I will response Legionnaires ''disease infection Problems to the hospital or the executive" that score is 2.11 points, showing the hospital staff''s cooperate for regarding the reduced infection source occurrence is not good. Based on the above study , To expect to provide reference to relevant units, and to increasing the prevention and control of Legionnaires ''disease concepts for hospital,Finally to strengthen infection control related specifications in hospital.

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

碩士
高雄師範大學
環境教育研究所
98
Many recent studies suggested that Legionella present in drinking water systems may be the major source for outbreaks of community-acquired Legionnaires disease (LD), especially in travel-associated LDs. Numerous reports and national guidelines have recommended routine environmental cultures for Legionella in cruises, hotels, convention centers, and public buildings. The World Game held in Kaohsiung during summer 2009 drew attention of the public and media whether the water supply in Kaohsiung was contaminated by Legionella given the previously detected hospital- and community-acquired LDs in Kaohsiung. The objective is to determine the presence of Legionella in Kaohsiung public water systems associated with World Game facilities. Thirty sampling locations were selected in Kaohsiung including large buildings (i.e. gymnasium, subway stations, and sports facilities) and outdoor recreational area. At least 3 water samples (250mL ea) were withdrawn from each sampling location. Sample concentration by filtration of 250 mL water sample was used to increase the yield of Legionella. A standardized procedure was followed for sample processing and enumeration. Latex agglutination test and direct fluorescent antibody technique were used for sero-typing of L. pneumophila. Total of 107 water samples were collected from 30 sampling locations. L. pneumophila was isolated from 13.3% (4/30) of the sampling locations. The Legionella positive rate for large buildings and outdoor recreational area was 11.1% (3/27) and 33.3% (1/3), respectively. Sampling locations in Fengshan and Tsoying districts have significantly higher positive rates of 50% (2/4) and 33.3% (2/6), respectively. The water samples from a newly opened gymnasium were 100% (3/3) positive for Legionella. Legionella was found in the public water supply in Kaohsiung; however, the Legionella positive rate is lower than the previously published data from hospital surveillance. Routine environmental surveillance for Legionella in public water supplies can be a good practice for evaluating risk of community-acquired and travel-associated LDs.

碩士
國立中山大學
高階經營碩士班
96
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.

RESUMO: O trabalho desenvolvido dividiu-se em duas áreas do conhecimento do género Legionella: a epidemiologia e a interação bactéria-hospedeiro natural. Estudou-se a epidemiologia da Doença dos Legionários em Portugal, no período entre 1987 e 2016, analisando 205 isolados, 178 dos quais recuperados de doentes com formas graves de pneumonia e 27 de amostras ambientais. Entre os isolados clínicos, 130 foram enviados através do Programa de Vigilância Epidemiológica Integrada da Doença dos Legionários e 48 foram recuperados num hospital da área de Lisboa, com vários casos de infeção hospitalar durante 21 anos e em cuja água do sistema de distribuição foi sistematicamente isolada a bactéria. Na tipificação destes isolados, utilizaram-se duas metodologias preconizadas pelo Grupo Europeu, anticorpos monoclonais (MAbs) do Painel de Dresden e a tipificação baseada em sequências (SBT). No grupo dos isolados provenientes de casos de infeção hospitalar foram aplicados mais dois métodos, o que avalia os polimorfismos de fragmentos amplificados por PCR (AFLP) e a sequenciação total do genoma (WGS). Os resultados da tipificação mostraram que todos os isolados pertencem à espécie Legionella pneumophila e maioritariamente ao serogrupo 1, e que todos, à exceção de um, reagem com o monoclonal MAb3/1. Na tipificação baseada em sequências, identificaram-se 39 perfis diferentes, 16 dos quais são novos, isto é, nunca antes identificados. Na sequenciação total do genoma, dos 48 isolados provenientes de infeção hospitalar, foi possível agrupá-los num mesmo clone, com uma microevolução marcada essencialmente pela fixação de mutações pontuais. Entre os isolados foi possível identificar três sub-linhagens, com base no número de diferenças nucleotídicas. A caracterização feita diretamente nas amostras clínicas por uma técnica de nested PCR permitiu a identificação de alguns alelos, verificando-se que só em amostras provenientes de sobrenadantes de culturas de amibas foi detetado o perfil alélico completo. Foi ainda efetuado o estudo da relação filogenética entre os perfis alélicos identificados em Portugal e os reportados à Base de dados Europeia por outros países. A população de Legionella responsável por casos de doença em Portugal é constituída por uma mistura de perfis específicos (exclusivos de Portugal) e de perfis comuns a outros países, tendo-se verificado nesta avaliação que 34 dos perfis têm relação com, pelo menos, um perfil dos existentes na referida Base. Na segunda parte desta tese, desenvolveu-se o estudo da interação Legionella-hospedeiro natural, tendo-se utilizado a espécie Acanthamoeba castellanii. Avaliaram-se as taxas de internalização e multiplicação às 4, 14 e 22h, a sensibilidade ao sódio e ao choque osmótico com potássio, e ainda, o transcritoma da bactéria, 22 horas após o início da co-cultura. Os resultados mostraram especificidade em relação às duas estirpes utilizadas e, embora estas apresentem neste momento do seu ciclo de vida um fenótipo característico de fase transmissível, verificou-se que o padrão de expressão génica é semelhante ao evidenciado por outras estirpes, na fase replicativa, sugerindo que a Legionella na fase final do seu ciclo de multiplicação intracelular, já está a preparar a próxima fase replicativa.
ABSTRACT: The work developed was divided into two different areas of knowledge of the genus Legionella: epidemiology and natural bacterial-host interaction. The epidemiology of Legionnaires‘ disease was studied in Portugal between 1987 and 2016, analyzing 205 isolates, 178 of which recovered from patients with severe forms of disease and 27 from environmental samples. Among the clinical isolates, 130 were sent by the Program of Integrated Epidemiological Surveillance of Legionnaires' Disease and 48 were recovered in a hospital in the Lisbon area, with several cases of hospital infection for 21 years, and with systematic isolation over the years in the water of the distribution system. For typing of these isolates, two methodologies recommended by the European Group, the monoclonal antibodies (MAbs) of the Dresden Panel and the sequence-based typing (SBT) were used. In the group of isolates from cases of hospital infection, two other methods were applied, amplified fragment length polymorphisms (AFLP) and whole genome sequencing (WGS). The typing results showed that all isolates belong to the species Legionella pneumophila and mainly to serogroup 1, and all but one reacts with the monoclonal MAb3/1. In sequence-based typing (SBT), 39 different profiles were identified, 16 of which were new profiles, therefore never previously identified. In the whole genome sequencing, of the 48 isolates from hospital infection, it was possible to group them in the same clone, with a microevolution marked essentially by the fixation of point mutations. Among the isolates, it was possible to identify three sub-lineages, based on the number of nucleotide differences. The direct characterization on clinical samples by a nested PCR technique allowed the identification of some alleles, and it was verified that only in samples from supernatants of amoeba cultures the complete allelic profile was detected. It was also carried out the study of the phylogenetic relationship between the allelic profiles identified in Portugal and those reported to the European Database by other countries. The population of Legionella responsible for cases of disease in Portugal consists of a mixture of specific profiles (exclusive of Portugal) plus profiles common to other countries, and it was verified in this evaluation that 34 of the profiles have relation with at least one profile of the European Database. In the second part of this thesis, the study of the interaction Legionella-natural host was developed, using the species Acanthamoeba castellanii. The rates of internalization and multiplication were evaluated at 4, 14 and 22h, sensitivity to sodium, osmotic shock with potassium, and bacterial transcriptome, 22 hours after the start of co-culture. The results showed specificity in relation to the two strains used, and although they presented a transmissible phenotype, it was verified that the pattern of gene expression is similar to that evidenced by strains in the replicative phase, suggesting that Legionella at the final phase of its intracellular multiplication cycle is already preparing the next replicative phase.

The Health Protection Branch of the Victorian Government Department of Health and Human Services monitors and responds to incidents that could adversely affect the health of Victorians. During 2014-2015, I completed a field placement with the branch, assisting with numerous public health investigations and responses. In doing so I fulfilled the requirements of the Master of Philosophy in Applied Epidemiology (MAE). The skills I gained are demonstrated in this thesis. Evaluation of a public health surveillance system is a core requirement for the MAE program. I evaluated Victoria’s surveillance and response to legionellosis, which includes both disease surveillance and environmental surveillance and response arms. I found little evidence to support the current practice of sampling and disinfecting cooling towers around the home and workplace for sporadic cases. Improved co-ordination between databases and strategic use of spatial software could help develop more targeted and useful approaches in the future. I embarked on two epidemiological projects. I designed a cross sectional study examining the prevalence of Legionella in domestic potable water and developed participant resources including letters to explain results, meeting the MAE requirement to communicate findings to a non-scientific audience. The study was not completed due to legal considerations; however the proposal and relevant participant resources are included as an appendix. I completed an epidemiological project estimating the number of notified sporadic Salmonella Typhimurium 9 Phage type 9 cases likely to be associated with a recurrent outbreak source during a five year period. I examined 301 clinical Salmonella isolates, including sporadic and outbreak isolates from a series of linked outbreaks, and used multi-locus variable number tandem repeat analysis and whole genome sequence results to estimate the number of isolates genetically linked to the outbreak strain. Outbreak cases accounted for just one third of all isolates estimated to be closely related to the main outbreak clade. This project inspired my lesson from the field, in which I taught MAE colleagues how to analyse MLVA data. I investigated an outbreak of Salmonella Typhimurium phage type 44 at a school function. I conducted a cohort study and interviewed twenty-nine out of thirty guests, of which ten were affected. Roast beef appetiser was the most likely food vehicle for Salmonella infection. Cross-contamination from raw eggs during preparation was a possible source. I analysed a public health dataset to assist a public health investigation into suspected antimony exposure in a rural mining town in Victoria. Residents were concerned about potential health effects from exposure to antimony dust from a local mine. Many sought urinary antimony testing to quantify exposure, with numerous elevated results. I used multivariate regression to examine risk factors for elevated urinary antimony and demonstrated residential proximity to the mine was not associated with urinary antimony results. Overwhelmingly, the largest risk factor for elevated results was the month of testing, consistent with false positive laboratory reports. This thesis documents my experience and capabilities gained during the MAE program, and demonstrates my contribution to protecting the public health of Victorians.

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Engenharia Clínica)
A Pal é uma lipoproteina que existe em maior abundância na parede celular da Legionella pneumophila. A localização e abundância da Pal tornam-na um antigénio importante no controlo de infecções causadas por este microrganismo. A obtenção desta proteína na sua estrutura nativa é, assim, importante para a produção de anticorpos que possam ser utilizados em testes de diagnóstico rápidos e na produção de vacinas. Tendo em conta o potencial de diagnóstico da Pal bem como a necessidade de uma produção proteica rápida e eficaz, estudou-se neste trabalho um novo sistema de produção de proteínas recombinantes em Escherichia coli e respectivos anticorpos: o tag de fusão H. Para isso procedeu-se ao estudo das condições óptimas de solubilidade da HPal em condições nativas, na E. coli e posteriormente passou-se ao aumento de escala e à purificação desta proteína através da cromatografia de afinidade. Posteriormente, procedeu-se à imunização dos animais com a HPal purificada ao longo de 15 dias e 25 dias. Findo esse tempo, recolheu-se o soro dos animais e procedeu-se à detecção dos anticorpos presentes no soro. A elaboração deste trabalho permitiu expressar de forma solúvel a HPal, usando 4 horas de indução, 1mM IPTG, a 37ºC. Além disso, foi possível equilibrar, lavar e eluir a proteína com 20 mM, 20 mM e 70 mM de imidazole, respectivamente. Apesar de apresentar alguns contaminantes, ficou também provado que o antigénio recombinante HPal induziu uma forte produção de anticorpos anti-Pal. O trabalho foi desenvolvido em estreita colaboração com a empresa Hitag Biotechnology, Lda.
The Pal is a lipoprotein that exists in greater abundance in the cell wall of Legionella Pneumophila. The location and abundance of Pal make it an important antigen in the control of infections caused by this microorganism. The achievement of this protein in its native structure is thus important for the production of antibodies that can be used in rapid diagnostic tests and vaccine production. Having regard to the diagnostic potential of Pal and the need for a rapid and efficient protein production, we studied in this work a new system for producing recombinant proteins in Escherichia coli and their antibodies: the fusion tag H. For this we proceeded to the study of optimal conditions for solubility of HPal in native conditions in E. coli and subsequently went to the scaling up and purification of this protein by affinity chromatography. Afterwards, if the immunization of animals with purified HPal over 15 days and 25 days. After this time, withdrew the serum of animals and proceeded to the detection of antibodies in serum. The preparation of this work allowed us to express the soluble form HPal, using four hours of induction, 1 mM IPTG at 37ºC. Moreover, it was possible to balance, wash and elute the protein with 20 mM, 20 mM and 70 mM imidazole, respectively. Despite showing some contaminants, it also proved that the HPal recombinant antigen induced strong production of anti-Pal. The work was developed in close collaboration with the company Hitag Biotechnology, Inc.