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.

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.

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.