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Abstract: Legionella spp. is an underreported cause of Community Acquired pneumonia that affects significant population specially in urban areas and its prevalence is on an increasing trend. The routine practice of testing for urinary antigen of Legionella in all suspected cases of pneumonia is prevalent is resource rich western countries. Although several studies have shown no distinct advantage of performing routine urinary antigen testing, this practice continues to be preferred by clinicians. In this viewpoint, we have discussed the advantages and disadvantages of urinary antigen testing, its relevance in current practice and its impact on clinical outcomes.

Objective Recommendations on the timing of Legionella urinary antigen tests for community-acquired pneumonia patients differ among guidelines in Japan, the United States, and European nations. We therefore evaluated the association between the timing of urinary antigen tests and in-hospital mortality in patients with Legionella pneumonia. Methods We conducted a retrospective cohort study using the Diagnosis Procedure Combination database, a nationwide database of acute care inpatients in Japan. Patients who underwent Legionella urinary antigen tests on the day of admission formed the tested group. Patients who were tested on day 2 of admission or later or were unexamined formed the control group. We performed a propensity score matching analysis to compare in-hospital mortality, length of hospital stay and duration of antibiotics use between the two groups. Results Of the 9,254 eligible patients, 6,933 were included in the tested group. One-to-one propensity score matching generated 1,945 pairs. The tested group had a significantly lower 30-day in-hospital mortality than the control group (5.7 vs. 7.7%; odds ratio, 0.72; 95% confidence intervals, 0.55-0.95; p=0.020). The tested group also showed a significantly shorter length of stay and duration of antibiotics use than the control group. Conclusion Urine antigen testing upon admission was associated with better outcomes in patients with Legionella pneumonia. Urine antigen tests upon admission may be recommended for all patients with severe community-acquired pneumonia.

Abstract: Legionnaires disease is an important, relatively uncommon, yet well known form of atypical community-acquired pneumonia (CAP). If not appropriately treated in the early stage of infection, it can be fatal. Several factors increase the risk of contracting Legionnaires disease, including age over 50 years, chronic cardiovascular disease, underlying respiratory disease, chronic renal disease, diabetes, smoking, any immunosuppressing condition, travel history, and certain types of employment. Legionnaires disease can present without the usual symptoms associated with pneumonia. The incidence of Legionnaires disease is increasing, and because of its morbidity and mortality, clinicians should consider it in the differential when treating patients with CAP. This article reviews the pathophysiology and treatment of Legionnaires disease and when to refer patients to tertiary centers for higher levels of care, including extracorporeal membrane oxygenation., (Copyright © 2022 American Academy of Physician Associates.)

Background: Guidelines recommend testing hospitalized patients with community-acquired pneumonia (CAP) for Legionella pneumophila only if the infection is severe or risk factors are present. There are no validated models for predicting Legionella., Objective: To derive and externally validate a model to predict a positive Legionella test., Design, Setting and Participants: Diagnostic study of adult inpatients with pneumonia using data from 177 US hospitals in the Premier Healthcare Database (training and hold-out validation sets) and 12 Cleveland Clinic Health System (CCHS) hospitals (external validation set). We used multiple logistic regression to predict positive Legionella tests in the training set, and evaluated performance in both validation sets., Main Outcome and Measures: The outcome was a positive Legionella test. Potential predictors included demographics and co-morbidities, disease severity indicators, season, region, and presence of a local outbreak., Results: Of 166,689 patients hospitalized for pneumonia, 43,070 were tested for Legionella and 642 (1.5%) tested positive. The strongest predictors of a positive test were a local outbreak (odds ratio [OR], 3.4), June-October occurrence (OR, 3.4), hyponatremia (OR, 3.3), smoking (OR, 2.4), and diarrhea (OR, 2.0); prior admission within 6 months (OR, 0.27) and chronic pulmonary disease (OR, 0.49) were associated with a negative test. Model c-statistics were 0.79 in the Premier and 0.77 in the CCHS validation samples. High-risk patients were only slightly more likely to have been tested than lower-risk patients. Compared to actual practice, the model-based testing strategy detected twice as many cases., Conclusions: Although Legionella is an uncommon cause of pneumonia, patient characteristics can identify individuals at high risk, allowing for more efficient testing., (© 2022 The Authors. Journal of Hospital Medicine published by Wiley Periodicals LLC on behalf of Society of Hospital Medicine.)

Objectives: Racial and socioeconomic disparities in the incidence of Legionnaires' disease have been documented for the past 2 decades; however, the social determinants of health (SDH) that contribute to these disparities are not well studied. The objective of this narrative review was to characterize SDH to inform efforts to reduce disparities in the incidence of Legionnaires' disease., Methods: We conducted a narrative review of articles published from January 1979 through October 2019 that focused on disparities in the incidence of Legionnaires' disease and pneumonia (inclusive of bacterial pneumonia and/or community-acquired pneumonia) among adults and children (excluding articles that were limited to people aged <18 years). We identified 220 articles, of which 19 met our criteria: original research, published in English, and examined Legionnaires' disease or pneumonia, health disparities, and SDH. We organized findings using the Healthy People 2030 SDH domains: economic stability, education access and quality, social and community context, health care access and quality, and neighborhood and built environment., Results: Of the 19 articles reviewed, multiple articles examined disparities in incidence of Legionnaires' disease and pneumonia related to economic stability/income (n = 13) and comorbidities (n = 10), and fewer articles incorporated SDH variables related to education (n = 3), social support (none), health care access (n = 1), and neighborhood and built environment (n = 6) in their analyses., Conclusions: Neighborhood and built-environment factors such as housing, drinking water infrastructure, and pollutant exposures represent critical partnership and research opportunities. More research that incorporates SDH and multilevel, cross-sector interventions is needed to address disparities in Legionnaires' disease incidence.

Legionnaires' disease (LD) ( Legionella ) is a common cause of community-acquired pneumonia (CAP) in those requiring hospitalization. Geographical variation in the importance of Legionella species as an aetiologic agent of CAP is poorly understood. We performed a systematic review and meta-analysis of population-based observational studies that reported the proportion of Legionella infection in patients with CAP (1 January 1990 to 31 May 2020). Using five electronic databases, articles were identified, appraised and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Univariate and multivariate meta-regression analyses were conducted using study design, WHO region, study quality and healthcare setting as the explanatory variables. We reviewed 2778 studies, of which 219 were included in the meta-analysis. The mean incidence of CAP was 46.7/100,000 population (95% CI: 46.6-46.8). The mean proportion of Legionella as the causative agent for CAP was 4.6% (95% CI: 4.4 to 4.7). Consequently, the mean Legionella incidence rate was 2.8/100,000 population (95% CI: 2.7-2.9). There was significant heterogeneity across all studies I 2 = 99.27% ( p < 0.0001). After outliers were removed, there was a decrease in the heterogeneity ( I 2 = 43.53%). Legionella contribution to CAP has a global distribution. Although the rates appear highest in high income countries in temperate regions, there are insufficient studies from low- and middle-income countries to draw conclusions about the rates in these regions. Nevertheless, this study provides an estimate of the mean incidence of Legionella infection in CAP, which could be used to estimate the regional and global burden of LD to support efforts to reduce the impact of this infection as well as to fill important knowledge gaps.

Introduction: Japan experienced a heavy rainfall event from June 28 to July 8, 2018, and many casualties were caused by both heavy rainfall and flooding. Few studies have investigated patients' characteristics and the causative pathogens of community-acquired pneumonia before and after heavy rainfall events. The aim of the present study was to evaluate the causative pathogens and clinical characteristics of hospitalized patients with community-acquired pneumonia before and after the heavy rainfall event using prospective cohort data., Methods: The study was divided into two periods: July to November 2013-2017 (before heavy rainfall) and July to November 2018 (after heavy rainfall). The patients' clinical characteristics and causative pathogens before and after the heavy rainfall were investigated. Regarding the causative pathogens, adjustments were made for precipitation and seasonal patterns., Results: There were no significant differences in the number and clinical characteristics of patients before and after heavy rainfall. However, the frequency of Legionella pneumonia was significantly higher after than before the heavy rainfall event (8.9% vs 3.0%, P = 0.02) and remained significant after adjusting for precipitation and season. Three of 7 Legionella pneumonia patients engaged in reconstruction work and 2 Legionella pneumonia patients had soil exposure., Conclusions: An increased risk of Legionella pneumonia after not only rainfall and serious flooding, but also following recovery work or soil exposure should be considered., (Copyright © 2021 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

The rapid identification of Legionella pneumonia is essential to optimize patient treatment and outcomes, and to identify potential public health risks. Previous studies have identified clinical factors which are more common in Legionella than non- Legionella pneumonia, and scores have been developed to assist in diagnosing cases. Since a Legionella pneumonia outbreak at VA Pittsburgh in 2012, nearly all patients with pneumonia have been tested for Legionella . The purpose of this study was to evaluate distinguishing characteristics between Legionella and non- Legionella pneumonia with the application of universal testing for Legionella in all cases of community-acquired pneumonia. We performed a retrospective case-control study matching Legionella and non- Legionella pneumonia cases occurring in the same month. Between January 2013 and February 2016, 17 Legionella and 54 non- Legionella cases were identified and reviewed. No tested characteristics were significantly associated with Legionella cases after Bonferroni correction. Outcomes of Legionella and non- Legionella pneumonia were comparable. Therefore, in veterans who underwent routine Legionella testing in an endemic area, factors typically associated with Legionella pneumonia were non-discriminatory.

Background/purpose: Legionella pneumophila had been recognized as an important pathogen for community-acquired pneumonia. We aimed to investigate clinical features and outcomes of patients with Legionnaires' disease at a tertiary medical center in northern Taiwan., Methods: From June 2012 to February 2017, a retrospective review of adult community-acquired. Legionnaires' disease at a medical center was conducted. All Legionella infections were confirmed by positive urinary Legionella antigen assay, sera indirect immunofluorescence assay, or sputum culture for Legionella. Literature review of Legionnaires' disease from Medline and PubMED websites was performed., Results: A total of 32 cases of Legionnaires' disease were identified. Their mean age was 64.3 years, with male predominance (27 cases, 84.3%). The underlying diseases were varied and most were attributed to chronic disorders, such as diabetes mellitus (31%) and cigarette smoking (40.6%). The most common symptoms were cough (68%) and fever (59.3%). More than half of patients (18, 56.2%) with Legionnaires' disease could initially present with extrapulmonary manifestations. Sixteen (50%) patients had delay in initiation of appropriate antibiotic therapy. Patients without adequately initiation of appropriate antibiotic therapy had higher proportion (11 of 16, 68.7%) of intensive care unit admission than patients with adequate initiation (5 of 16, 31.2%). Our results inferred that a delay in treatment might result in worsening of disease severity and the need for more intensive management. Overall mortality rate was 21.8%. Development of vasopressor requirement is an independent risk factor associated with mortality., Conclusion: Legionnaires' disease in Taiwan frequently present with extrapulmonary manifestations. Patients with hemodynamic instability that need vasopressor therapy associated with mortality., (Copyright © 2017. Published by Elsevier B.V.)

Importance: Legionnaires disease (LD) incidence is increasing in the United States. Health care facilities are a high-risk setting for transmission of Legionella bacteria from building water systems to occupants. However, the contribution of LD in health care facilities to national LD rates is not well characterized., Objectives: To determine the burden of LD in US Department of Veterans Affairs (VA) patients and to assess the amount of LD with VA exposure., Design, Setting, and Participants: Retrospective cohort study of reported LD data in VA medical facilities in a national VA LD surveillance system from January 1, 2014, to December 31, 2016. The study population included total veteran enrollees and enrollees who used the VA health care system., Main Outcomes and Measures: The primary outcome was assessment of annual LD rates, categorized by VA and non-VA exposure. Legionnaires disease rates for cases with VA exposure were determined on both population and exposure potential levels. Rates by VA exposure potential were calculated using inpatient bed days of care, long-term care resident days, or outpatient encounters. In addition, types and amounts of LD diagnostic testing were calculated. Case and testing data were analyzed nationally and regionally., Results: There were 491 LD cases in the case report surveillance system from January 1, 2014, to December 31, 2016. Most cases (447 [91%]) had no VA exposure or only outpatient VA exposure. The remaining 44 cases had VA exposure from overnight stays. Total LD rates from January 1, 2014, to December 31, 2016, increased for all VA enrollees (from 1.5 to 2.0 per 100 000 enrollees; P = .04) and for users of VA health care (2.3 to 3.0 per 100 000 enrollees; P = .04). The LD rate for the subset who had no VA exposure also increased (0.90 to 1.47 per 100 000 enrollees; P < .001). In contrast, the LD rate for patients with VA overnight stay decreased on a population level (5.0 to 2.3 per 100 000 enrollees; P < .001) and an exposure level (0.31 to 0.15 per 100 000 enrollees; P < .001). Regionally, the eastern United States had the highest LD rates. The urine antigen test was the most used LD diagnostic method; 49 805 tests were performed in 2015-2016 with 335 positive results (0.67%)., Conclusions and Relevance: Data in the VA LD databases showed an increase in overall LD rates over the 3 years, driven by increases in rates of non-VA LD. Inpatient VA-associated LD rates decreased, suggesting that the VA's LD prevention efforts have contributed to improved patient safety.

Background/purpose: Legionella pneumophila had been recognized as a pathogen for both healthcare-associated and community-acquired pneumonia. We aimed to evaluate clinical features and outcomes of patients with Legionnaires' disease at a tertiary medical center in southern Taiwan., Methods: From January 2005 to December 2013, a retrospective study of adult cases of Legionnaires' disease was conducted in a 1200-bed tertiary hospital. Their medical records were reviewed for further evaluation and analysis., Results: A total of 61 cases of Legionnaires' disease were identified during the study period. Their mean age was 61.1 years, with male predominance (43, 70.5%). Among them, 30 (49.2%) had healthcare-associated pneumonia (HCAP), 20 (32.8%) had community-acquired pneumonia, and notably 11 (18.0%) were caregivers. Patients with healthcare-associated pneumonia tend to have higher Charlson comorbidity scores than those with community-acquired pneumonia (3.6±2.4 vs. 1.9±1.9, p=0.008) and caregivers (0.5±0.5, p<0.001). Six patients died, resulting in an in-hospital mortality rate of 9.8%. Underlying cancer (66.7% vs. 20.0%, p=0.028) and a higher Charlson comorbidity score (4.7±2.6 vs. 2.2±2.2, p=0.013) were related to a fatal outcome., Conclusion: L. pneumophila remains an important pathogen for pneumonia acquired from the community or associated with healthcare facility. Healthy caregivers may potentially be at risk for Legionella infection in certain clinical settings., (Copyright © 2017. Published by Elsevier B.V.)

Using the Nationwide Inpatient Sample and US weather data, we estimated the probability of community-acquired pneumonia (CAP) being diagnosed as Legionnaires' disease (LD). LD risk increases when weather is warm and humid. With warm weather, we found a dose-response relationship between relative humidity and the odds for LD. When the mean temperature was 60°-80°F with high humidity (>80.0%), the odds for CAP being diagnosed with LD were 3.1 times higher than with lower levels of humidity (<50.0%). Thus, in some regions (e.g., the Southwest), LD is rarely the cause of hospitalizations. In other regions and seasons (e.g., the mid-Atlantic in summer), LD is much more common. Thus, suspicion for LD should increase when weather is warm and humid. However, when weather is cold, dry, or extremely hot, empirically treating all CAP patients for LD might contribute to excessive antimicrobial drug use at a population level.

Rationale: Legionella pneumophila is an uncommon cause of community-acquired pneumonia in the south central region of the United States, and regular testing may not be cost effective in areas of low incidence., Objectives: To evaluate the incidence of Legionella in central Texas and to determine the cost effectiveness of Legionella urinary antigen testing., Methods: We performed a single-center retrospective cohort study of patients admitted with pneumonia between January 2001 and December 2013. Patients were identified by Binax Legionella urinary antigen and International Classification of Disease, Ninth Revision codes. Demographic characteristics and clinical history of the confirmed Legionella pneumonia cases were obtained by chart review. Descriptive statistics were used to describe patient characteristics., Measurements and Main Results: Over 12 years, 5,807 patients with 11,377 admissions for pneumonia were tested for Legionella urinary antigen. A positive Legionella urinary antigen was found in 17 patients. Cumulative incidence during the study period was 0.23%. Among the Legionella-positive patients, intensive care unit admission and median length of stay were 58.8% and 8.5 days, respectively. Most patients (64.7%) met American Thoracic Society criteria for severe pneumonia. All patients empirically received either a macrolide or fluoroquinolone covering Legionella. There were two in-hospital and three total 90-day deaths in those with a positive urinary antigen. The estimated cost of screening this population with Legionella urinary antigen was $214,438 over 13 years., Conclusions: This study reveals the low incidence of Legionella pneumonia in central Texas. Use of guideline-concordant antibiotic treatment provides coverage for Legionella. We speculate that testing in a low-prevalence area would not influence outcomes or be cost effective.

Background: Legionella pneumophila, a major cause of Legionnaires' disease, accounts for 2-15 % of all community-acquired pneumonia requiring hospitalization and up to 30 % of community-acquired pneumonia requiring intensive care unit admission. Early initiation of appropriate antimicrobial therapy is a crucial step in the prevention of morbidity and mortality. However, recognition of Legionnaires' disease continues to be challenging because of its nonspecific clinical features. We sought to describe hospitalized community-acquired Legionnaires' disease to increase awareness of this important and potentially lethal disease., Methods: A retrospective multicenter observational study was conducted with all patients with confirmed Legionnaires' disease in the Niagara Region of the Province of Ontario, Canada, from June to December 2013., Results: From June to December 2013, there were 14 hospitalized cases of Legionnaires' disease in the Niagara Region. Of these, 86 % (12 patients) had at least one comorbidity and 71 % (10 patients) were cigarette smokers. In our cohort, Legionnaires' disease was diagnosed with a combination of a urinary Legionella antigen test and a Legionella real-time polymerase chain reaction assay. Delay in effective antimicrobial therapy in the treatment of Legionella infection led to clinical deterioration. The majority of patients had met systemic inflammatory response syndrome criteria with fever >38 °C (71 %), heart rate >90 beats per minute (71 %), and respiratory rate >20 breaths per minute (86 %). Eleven patients (79 %) required admission to the intensive care unit or step-down unit, and nine patients (64 %) required intubation. Clinical improvement after initiation of antimicrobials was protracted., Conclusions: Legionnaires' disease should be considered during the late spring and summer months in patients with a history of tobacco use and various comorbidities. Clinically, patients presented with severe, nonspecific, multisystem disease characterized by shortness of breath, abnormal vital signs, and laboratory derangements including hyponatremia, elevated creatine kinase, and evidence of organ dysfunction. In addition, antimicrobial therapy with newer macrolides or respiratory fluoroquinolones should be initiated for severe community-acquired pneumonia requiring intensive care unit admission, prior to laboratory confirmation of diagnosis, especially when a clinical suspicion of Legionella infection exists.

Background: The use of rapid microbiological tests is supported by antimicrobial stewardship policies. Targeted antibiotic therapy (TAT) for community-acquired pneumonia (CAP) with positive urinary antigen test (UAT) has been associated with a favorable impact on outcome. We aimed to determine the factors associated with TAT prescription., Patients and Methods: We conducted a retrospective multicenter study including all patients presenting with CAP and positive UAT for Streptococcus pneumoniae or Legionella pneumophila from January 2010 to December 2013. Patients presenting with aspiration pneumonia, coinfection, and neutropenia were excluded. CAP severity was assessed using the Pneumonia Severity Index (PSI). TAT was defined as the administration of amoxicillin for pneumococcal infection and either macrolides or fluoroquinolones (inactive against S. pneumoniae) for Legionella infection., Results: A total of 861 patients were included, including 687 pneumococcal infections and 174 legionellosis from eight facilities and 37 medical departments. TAT was prescribed to 273 patients (32%). Four factors were found independently associated with a lower rate of TAT: a PSI score≥4 (OR 0.37), Hospital A (OR 0.41), hospitalization in the intensive care unit (OR 0.44), and cardiac comorbidities (OR 0.60). Four other factors were associated with a high rate of TAT: positive blood culture for S. pneumoniae (OR 2.32), Hospitals B (OR 2.34), E (OR 2.68), and H (OR 9.32)., Conclusion: TAT in CAP with positive UAT was related to the hospitals as well as to patient characteristics., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Between 1 August and 6 September 2013, an outbreak of Legionnaires' disease (LD) with 159 suspected cases occurred in Warstein, North Rhine-Westphalia, Germany. The outbreak consisted of 78 laboratory-confirmed cases of LD, including one fatality, with a case fatality rate of 1%. Legionella pneumophila, serogroup 1, subtype Knoxville, sequence type 345, was identified as the epidemic strain. A case-control study was conducted to identify possible sources of infection. In univariable analysis, cases were almost five times more likely to smoke than controls (odds ratio (OR): 4.81; 95% confidence interval (CI): 2.33-9.93; p < 0.0001). Furthermore, cases were twice as likely to live within a 3 km distance from one identified infection source as controls (OR: 2.14; 95% CI: 1.09-4.20; p < 0.027). This is the largest outbreak of LD in Germany to date. Due to a series of uncommon events, this outbreak was most likely caused by multiple sources involving industrial cooling towers. Quick epidemiological assessment, source tracing and shutting down of potential sources as well as rapid laboratory testing and early treatment are necessary to reduce morbidity and mortality. Maintenance of cooling towers must be carried out according to specification to prevent similar LD outbreaks in the future.

We studied the timing of occurrence of 1676 sporadic, community-acquired cases of Legionnaires' disease in England and Wales between 1993 and 2008, in relation to temperature, relative humidity, rainfall, windspeed and ultraviolet light using a fixed-stratum case-crossover approach. The analysis was conducted using conditional logistic regression, with consideration of appropriate lag periods. There was evidence of an association between the risk of Legionnaires' disease and temperature with an apparently long time lag of 1-9 weeks [odds of disease at 95th vs. 75th centiles: 3·91, 95% confidence interval (CI) 2·06-7·40], and with rainfall at short time lags (of 2-10 days) (odds of disease at 75th vs. 50th centiles: 1·78, 95% CI 1·50-2·13). There was some evidence that the risk of disease in relation to high temperatures was greater at high relative humidities. A higher risk of Legionnaires' disease may be indicated by preceding periods of warmer wetter weather.

Recent studies have left absolutely no doubt that tobacco increases susceptibility to bacterial lung infection, even in passive smokers. This relationship also shows a dose-response effect, since the risk reduces spectacularly 10 years after giving up smoking, returning to the level of non-smokers. Streptococcus pneumoniae is the causative microorganism responsible for community-acquired pneumonia (CAP) most frequently associated with smoking, particularly in invasive pneumococcal disease and septic shock. It is not clear how it acts on the progress of pneumonia, but there is evidence to suggest that the prognosis for pneumococcal pneumonia is worse. In CAP caused by Legionella pneumophila, it has also been observed that smoking is the most important risk factor, with the risk rising 121% for each pack of cigarettes smoked a day. Tobacco use may also favor diseases that are also known risk factors for CAP, such as periodontal disease and upper respiratory viral infections. By way of prevention, while giving up smoking should always be proposed, the use of the pneumococcal vaccine is also recommended, regardless of the presence of other comorbidities., (Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.)

Legionella pneumophila has been increasingly recognized as a cause of community-acquired pneumonia (CAP) and an important public health problem worldwide. We conducted the present study to assess trends in epidemiology, diagnosis, clinical features, treatment, and outcomes of sporadic community-acquired L. pneumophila pneumonia requiring hospitalization at a university hospital over a 15-year period (1995-2010). Among 3934 nonimmunosuppressed hospitalized patients with CAP, 214 (5.4%) had L. pneumophila pneumonia (16 cases were categorized as travel-associated pneumonia, and 21 were part of small clusters). Since the introduction of the urinary antigen test, the diagnosis of L. pneumophila using this method remained stable over the years (p = 0.42); however, diagnosis by means of seroconversion and culture decreased (p < 0.001 and p = 0.001, respectively). The median age of patients with L. pneumophila pneumonia was 58.2 years (SD 13.8), and 76.4% were male. At least 1 comorbid condition was present in 119 (55.6%) patients with L. pneumophila pneumonia, mainly chronic heart disease, diabetes mellitus, and chronic pulmonary disease. The frequency of older patients (aged >65 yr) and comorbidities among patients with L. pneumophila pneumonia increased over the years (p = 0.06 and p = 0.02, respectively). In addition, 100 (46.9%) patients were classified into high-risk classes according to the Pneumonia Severity Index (groups IV-V). Twenty-four (11.2%) patients with L. pneumophila pneumonia received inappropriate empirical antibiotic therapy at hospital admission. Compared with patients who received appropriate empirical antibiotic, patients who received inappropriate therapy more frequently had acute onset of illness (p = 0.004), pleuritic chest pain (p = 0.03), and pleural effusion (p = 0.05). The number of patients who received macrolides decreased over the study period (p < 0.001), whereas the number of patients who received levofloxacin increased (p < 0.001). No significant difference was found in the outcomes between patients who received erythromycin and clarithromycin. However, compared with macrolide use during hospital admission, levofloxacin therapy was associated with a trend toward a shorter time to reach clinical stability (median, 3 vs. 5 d; p = 0.09) and a shorter length of hospital stay (median, 7 vs. 10 d; p < 0.001). Regarding outcomes, 38 (17.8%) patients required intensive care unit (ICU) admission, and the inhospital case-fatality rate was 6.1% (13 of 214 patients). The frequency of ICU admission (p = 0.34) and the need for mechanical ventilation (p = 0.57) remained stable over the study period, but the inhospital case-fatality rate decreased (p = 0.04). In the logistic regression analysis, independent factors associated with severe disease (ICU admission and death) were current/former smoker (odds ratio [OR], 2.96; 95% confidence interval [CI], 1.01-8.62), macrolide use (OR, 2.40; 95% CI, 1.03-5.56), initial inappropriate therapy (OR, 2.97; 95% CI, 1.01-8.74), and high-risk Pneumonia Severity Index classes (OR, 9.1; 95% CI, 3.52-23.4). In conclusion, L. pneumophila is a relatively frequent causative pathogen among hospitalized patients with CAP and is associated with high morbidity. The annual number of L. pneumophila cases remained stable over the study period. In recent years, there have been significant changes in diagnosis and treatment, and the inhospital case-fatality rate of L. pneumophila pneumonia has decreased.

Sporadic community-acquired legionellosis (SCAL) can be acquired through contaminated aerosols from residential potable water. Electricity-dependent hot-water tanks are widely used in the province of Quebec (Canada) and have been shown to be frequently contaminated with Legionella spp. We prospectively investigated the homes of culture-proven SCAL patients from Quebec in order to establish the proportion of patients whose domestic potable hot-water system was contaminated with the same Legionella isolate that caused their pneumonia. Water samples were collected in each patient's home. Environmental and clinical isolates were compared using pulsed-field gel electrophoresis. Thirty-six patients were enrolled into the study. Legionella was recovered in 12/36 (33%) homes. The residential and clinical isolates were found to be microbiologically related in 5/36 (14%) patients. Contaminated electricity-heated domestic hot-water systems contribute to the acquisition of SCAL. The proportion is similar to previous reports, but may be underestimated.

Legionella are present in the environment as well as in biofilms of water installation systems. Most Legionella live in amoebae. More than 51 different species of Legionella have been identified; however, most pneumonias are caused by Legionella pneumophila serogroup 1. Legionnaire's disease has an incidence of about 4% in Germany. Most cases of Legionnaire's disease are sporadic. Microbiological identification of Legionella can be achieved by cultivation of Legionella spp. on specific media, performing of Legionella-specific PCR from respiratory samples, or Legionella urinary antigen testing. Patients with severe underlying diseases, patients receiving immunosuppression, and patients who are heavy smokers have a predisposition to Legionnaire's disease. Men are significantly more often affected. Whereas outpatients show a mild clinical course, mortality for hospitalized patients is 11.2%. It can be assumed that only a minority of cases of Legionnaire's disease is recognized and reported in Germany.

An outbreak of Legionnaires' disease affected 12 customers of a supermarket in a town in Catalonia, Spain, between August and November 2006. An epidemiological and environmental investigation was undertaken. Preliminary investigation showed that all patients had visited the same supermarket in this town where a mist machine was found in the fish section. Water samples were collected from the machine and from the supermarket's water distribution system when high-risk samples were excluded. Environmental samples from the mist machine and clinical samples from two patients tested positive for L. pneumophila serogroup 1 and had the same molecular pattern. The PFGE pattern detected in the clinical and mist-machine isolates had never previously been identified in Catalonia prior to the outbreak and has not been identified since. Four days after turning off the machine, new cases ceased appearing. Molecular study supports the hypothesis that the mist machine from the fish section of the supermarket was the source of infection. We believe it is essential to include exposure to mist machines in any legionellosis epidemiological survey.

We retrospectively investigated patients with Legionnaires disease (LD) who had been admitted to the Baskent University Alanya Teaching and Research Hospital, Ankara, Turkey, from January 2002 to September 2009. Twenty definitive cases were followed as LD, 17 (85%) of which were travel associated. The mean age was 61.5 ± 9.5 years (range, 39-77 years). Diabetes mellitus was found in 7 (41.2%) of those patients. Gastrointestinal or neurologic abnormalities were found approximately in two-thirds and relative bradycardia in 9 (52.9%). LD was severe in 11 (64.7%) patients, which required intensive care unit follow-up. Although appropriate antibiotic therapy was initiated in all patients on admission day, 4 (23.5%) deaths occurred. In conclusion, clinicians should remain vigilant about the diagnosis of LD in patients with community-acquired pneumonia, especially in the presence of extrapulmonary involvement, risk factors for LD, and a history of recent travel. As in our cases, mortality is still high in sporadic cases despite early appropriate treatment., (Copyright © 2010 Elsevier Inc. All rights reserved.)

During August and September 2010, an outbreak comprising 22 cases of Legionnaires' disease was identified by the public health service in Wales. The cases are distributed over a wide geographical area in South East Wales. There are two space-time clusters centred on the upper Rhymney Valley and the lower Cynon Valley respectively. Epidemiological investigations are compatible with cooling towers in each location as the potential source, but environmental inspections were satisfactory and microbiological investigations are inconclusive.

Unlabelled: We performed urinary antigen tests for pneumococcus and Legionella for patients with community-acquired pneumonia (CAP), to prescribe a documented antibiotic therapy. We report the efficiency of low-spectrum antibiotic treatment, illustrating the inappropriateness of bacteriological respiratory sampling., Patients and Methods: Patients with CAP were enrolled from three different units; the pneumonia severity index was used to assess the disease. Respiratory samples were also listed. Low-spectrum antibiotic therapy was amoxicillin for pneumococcal infection, and macrolides or non-anti-pneumococcal fluoroquinolone for legionellosis., Results: Six hundred and seventy-five CAP were diagnosed during the study period,, 150 with positive urinary antigen tests (23%), among which 108 pneumococcal infections (73%), 40 legionellosis (26%), and two mixed infections. The pneumonia severity index was 106+/-38. Amoxicillin was prescribed in 108 cases, fluoroquinolone in 24 cases, macrolide in 18 cases. The outcome was favourable for 138 patients (92%). Eighty three respiratory samples allowed identification of a bacterium for 58 patients (39%), among which 24 strains were not in the antibiotic spectrum: Haemophilus influenzae and Pseudmomonas aeruginosa in six cases, Staphylococcus aureus in five cases, Klebsiella pneumoniae in two cases, and another Gram negative bacillus in five cases. These strains were resistant in vitro to the prescribed treatment in 19/24 cases (79%). One out of 12 patients who died had a respiratory sample positive for Enterobacter spp strain resistant to the ongoing antibiotic treatment., Conclusion: The low-spectrum antibiotic therapy based on urinary antigen tests is efficient, and demonstrates respiratory tract colonisation with bacteriological strains usually considered as pathogenic.

Background & Objectives: Legionella pneumophila and other members of this genus are important respiratory pathogens but legionellosis often remains a neglected and under reported condition. Hence, this study was done to find out the presence of this organism in patients admitted to a tertiary care hospital with community-acquired pneumonia (CAP)., Methods: A total of 470 lower respiratory tract samples and 24 water samples from hospital outlets were examined. Culture was done on buffered charcoal yeast extract agar with supplements and identification of the isolates was done by microscopy and biochemical tests., Results: L. pneumophila could be isolated from 12 (2.55%) patients suffering from community-acquired lower respiratory tract infection, unassociated with other aetiological agents of bacterial pneumonia. Of the 24 water samples tested, 8 (33.3%) grew the same organism., Interpretation & Conclusion: Our study has shown that Legionella is present in the hospital environment and was the aetiological agent of lower respiratory tract infection in 2.55 per cent of patients. A larger study and reports from other parts of the country may help in determining the true significance of legionellosis in India.

Objectives: To describe the multidisciplinary investigation and management of a rapidly increasing number of cases of Legionnaires' disease in the North Shropshire area, UK during August 2006., Study Design: Epidemiological and environmental investigation of a cluster of cases of Legionnaires' disease., Methods: Outbreak investigation included: agreeing case definitions; case finding; epidemiological survey; identification and environmental investigation of potential sources; microbiological analysis of clinical and environmental samples; mapping the location of potential sources; and the movement and residence of cases., Results: Three cases of Legionnaires' disease were admitted to a local hospital between 30 and 31 August 2006. Two of these cases were Shropshire residents, with the third living in Wales. A fourth case was also identified which, it was thought, may have been linked to this cluster as the patient had a history of travel to the same area as the two Shropshire residents. Over the next few weeks, three more cases were identified, two of whom were admitted to hospital. Subsequent detailed environmental, epidemiological and microbiological investigation did not support the hypothesis that any of these cases could be linked to a common source., Conclusions: The results of this investigation strongly suggest that a single source was not responsible for the cluster, and it was concluded that this incident was a pseudo-outbreak. This investigation serves as a reminder that clusters can and do occur, and that an apparent outbreak may be a collection of sporadic cases distinguishable only by rigorous epidemiological, environmental and microbiological investigation., (Copyright 2010. Published by Elsevier Ltd.)

Background: In France, Legionnaires disease is mainly caused by Legionella pneumophila. Here, we investigated possible host factors associated with susceptibility to community-acquired Legionnaires disease caused by the endemic Paris and Lorraine strains., Methods: We conducted a double-nested exploratory case-control study with use of data from the French national surveillance network of incident Legionnaires disease cases notified from 1998 through 2007. Patients with community-acquired Legionnaires disease and an L. pneumophila serogroup 1 isolate were eligible. Case patients were patients infected by the Paris or Lorraine strain, and control patients were those infected by sporadic strains. Epidemiological and clinical factors associated with infection with the Paris and Lorraine strains were assessed by calculating adjusted odds ratios (aOR) in multivariate logistic regression models., Results: We studied 1090 patients infected by sporadic strains (n = 920), the Paris strain (n = 80), or the Lorraine strain (n = 90). Infection with the Paris strain was significantly associated with female sex (aOR, 1.98; 95% confidence interval [CI], 1.19-3.28), steroid therapy (aOR, 3.16; 95% CI, 1.76-5.68), and a history of cancer or hematologic malignancies (aOR, 2.08; 95% CI, 1.15-3.76). In addition, the mortality rate was higher among patients infected with the Paris strain than in the control group (38% vs. 25.5%). The Lorraine strain was associated with smoking (aOR, 1.82; 95% CI, 1.14-2.91) and reduced mortality (9.9%). ., Conclusion: Several host characteristics were associated with the risk of infection by endemic strains of L. pneumophila serogroup 1. These findings may help to guide preventive measures. Factors predisposing patients to infection by specific strains need to be explored further.

We report the investigation of a community-acquired outbreak of Legionnaires' disease. An epidemiological, environmental, and meteorological investigation was undertaken. Fifty-five cases were reported in October and November 2005. The exposure occurred in a large area, with 12 cases (21.8%) located between 1,800 and 3,400 metres from the source. Water sample cultures showed that Legionella pneumophila serogroup 1 (Lp-1) was present in five cooling towers in two industrial locations in Gurb (plants A and B). Two Lp-1 strains were recovered from plants A and B, but only Lp-1 strains from plant A showed a pulsed-field gel electrophoresis (PFGE) profile identical to those obtained from three of the cases. Inspection of the cooling towers in plant A revealed inadequate maintenance. Weather conditions in October 2005, with mostly high temperatures and high humidity, together with the flat terrain could have been favouring factors. This study showed a community outbreak from a cooling tower as a common source in a large area. Climate and terrain could explain the dissemination of contaminated aerosols.

Results of studies of biological samples from patients with community-acquired pneumonia and samples from environment during Legionnaires' disease outbreak in town Verkhnyaya Pyshma (Sverdlovsk region) in July-August 2007 performed by PCR analysis are presented.

Data on postmortem examination of five patients deceased during Legionnaires' outbreak in town Verkhnyaya Pyshma are presented in the article. Feature of course of the disease was severe affection of the lungs with development of toxic shock. Pathomorphological picture in lungs was characterized by polymorphism, presence of shock reaction and ventilator-associated pneumonia (atelectases, distelectases, tracheobronchitis). In autopsy material from four fatal cases Legionella pneumophila serogroup 1 was detected. Causative agent of pneumonia was not determined in one fatal case although comparison of clinical and morphological characteristics of this case with other four cases as well as detection of Gram-negative bacillus in alveolar macrophages allowed to consider this case of pneumonia as caused by Legionella. In studied fatal cases postmortem diagnoses were ascertained in which main disease was bilateral pneumonia caused by Legionella pneumophila serogroup 1 complicated by toxic shock.

Data on organization of medical care during outbreak of Legionnaires' disease in July-August, 2007 in town Verkhnyaya Pyshma in Sverdlovsk region are presented. Special feature of this outbreak was spreading of infection in boundaries of the town with total population of 70,600 people. Results of organizational work of health authorities in order to provide timely and adequate medical care for patients with Legionnaires' disease on both outpatient and inpatient levels of care, conduction of preventive measures in foci of infection, coordination of interaction between different medical organizations and services are summarized in the article.

Bacteriologic, serologic, and PCR tests of blood, sputum, serum and autopsy samples from 91 patients were performed during outbreak of pneumonia in town Verkhnyaya Pyshma in July-August 2007. Streptococcus pneumoniae was isolated from 20% of diagnostically meaningful samples of sputum and from 50% of autopsy samples. Diagnosis of Legionnaires' disease was confirmed in 48% of cases. It was shown that association of Streptococcus pneumoniae and Legionella pneumophila determined the affect during such pneumonia. Need for establishment of diagnostic procedure for patients with pneumonia including those caused by atypical agents was revealed.

We describe the case of a 66-year-old man with a culture-proven Legionella pneumonia after kidney transplantation. The patient developed the infection 15 days after discharge from a university hospital. Legionella pneumonia caused by Legionella pneumophila serogroup 5/10 was established by positive direct fluorescence assay, positive urinary-antigen detection and isolation of the causative agent. The infection was successfully treated by giving appropriate antibiotics, but the further course was complicated by invasive aspergillosis, cytomegalovirus pneumonia, failure of the transplanted kidney and development of septic anaemia. Four months after the diagnosis of Legionella pneumonia the patient died of multi-organ failure. The microbiological and epidemiological investigation revealed that strains from the water supply of the patient's private home were indistinguishable from the patient's isolate by amplified fragment length polymorphism analysis and sequence-based typing (SBT). Unrelated strains of serogroups 4, 5, 8 and 10 from the Dresden strain collection were of different SBT types. Thus, SBT is a very useful tool for epidemiological investigation of infections by L. pneumophila serogroups other than serogroup 1.

Objective: Description of an outbreak of legionnaires' disease originating in one of the cooling towers of a hospital., Patients and Methods: This study included patients with confirmed pneumonia caused by Legionella pneumophila serogroup 1 and related to the Vallcarca neighborhood of Barcelona (Spain) in August 2004. Exposure was determined by a standardized questionnaire. An environmental investigation was carried out to identify the source of the outbreak. A descriptive analysis including incidence rates estimation was performed, as well as molecular study to document the genetic identity among human and environmental strains., Results: Thirty-three cases of L. pneumophila pneumonia were detected. Median age was 68 years and 70% of the affected patients were men. Incidence rate among residents in less than 200 meters of the source and older than 65 was 888.9 cases/100,000 inhabitants. Lethality rate was 6%. Four seasonal cooling towers that were not registered with the authorities were identified in a health care center. L. pneumophila was isolated from all four and at least one colony in each tower had the same genetic profile as the strains isolated from patients., Conclusions: An association was demonstrated between a community outbreak of legionellosis and unregistered seasonal cooling towers located in a hospital. All risk facilities should be registered and inspected to ensure that they fulfill current legislation requirements.

The in-vitro activity of telithromycin and comparator antibacterial agents was determined against clinical isolates of Legionella pneumophila collected in the PROTEKT surveillance study. In total, 133 isolates were collected between 1999 and 2004 from 13 countries (Australia, Belgium, Czech Republic, France, Germany, Hungary, Ireland, Italy, Japan, Portugal, Spain, Sweden and the USA). MICs were determined by broth microdilution. Telithromycin maintained activity between Year 1 (MIC(90) 0.015 mg/L) and Year 5 (MIC(90) 0.03 mg/L), as did the comparator antibacterial agents. Telithromycin appears to be a candidate for coverage of legionellosis in the empirical treatment of community-acquired respiratory tract infection.

The aim of this study was to characterise community-acquired pneumonia (CAP) caused by atypical pathogens by combining distinctive clinical and epidemiological features and novel biological markers. A population-based prospective study of consecutive patients with CAP included investigation of biomarkers of bacterial infection, e.g., procalcitonin, C-reactive protein and lipopolysaccharide-binding protein (LBP) levels. Clinical, radiological and laboratory data for patients with CAP caused by atypical pathogens were compared by univariate and multivariate analysis with data for patients with typical pathogens and patients from whom no organisms were identified. Two predictive scoring models were developed with the most discriminatory variables from multivariate analysis. Of 493 patients, 94 had CAP caused by atypical pathogens. According to multivariate analysis, patients with atypical pneumonia were more likely to have normal white blood cell counts, have repetitive air-conditioning exposure, be aged <65 years, have elevated aspartate aminotransferase levels, have been exposed to birds, and have lower serum levels of LBP. Two different scoring systems were developed that predicted atypical pathogens with sensitivities of 35.2% and 48.8%, and specificities of 93% and 91%, respectively. The combination of selected patient characteristics and laboratory data identified up to half of the cases of atypical pneumonia with high specificity, which should help clinicians to optimise initial empirical therapy for CAP.

An outbreak of Legionnaires' disease (LD) occurred in Lidköping, Sweden, in August 2004. A cooling tower was identified as the probable source of infection. During the outbreak period an unexpected 3-6-fold increase in pneumonia patients was noted at the local hospital. During 7 weeks LD was diagnosed in 15 patients by urinary antigen and/or sputum culture. Additionally, 15 LD patients were diagnosed later by serology. Patients with LD were generally younger, more healthy, and more often smokers compared to other pneumonia patients. On admittance they had more severe symptoms with high fever and raised CRP levels, and more often hyponatraemia, gastrointestinal and CNS symptoms. A causative agent besides Legionella was found in 2 patients only. A significant titre rise for Mycoplasma and/or Chlamydophila pneumoniae was found in 13 of 29 tested patients with confirmed LD. We conclude that the clinical diagnosis of LD is difficult and that available diagnostic methods detect only a minority of patients in the acute phase. Therefore in severe pneumonia, empirically targeted therapy should be instituted on clinical grounds irrespective of the results of diagnostic tests. The observation of increased antibody levels for M. and C. pneumoniae suggests an unspecific immune reaction and merits further study.

During the period 6-28 July 2006, 30 confirmed cases of Legionella infection were identified in Amsterdam, 2 of which were fatal. All had a positive urinary antigen test, by which Legionella pneumophila serogroup I could be demonstrated. Consultations between the parties involved in the control of infectious diseases started on July 7th, as soon as it became clear that there was an outbreak. On July 10th it was established that relatively many of these patients lived in the eastern part of the city centre. After a study of the prevailing winds during the past 3 weeks, the search for installations containing water was started. A cooling tower in the town centre was closed on July 11th by way of precaution. During the following week, this tower was proven to be the source of the outbreak.

Objective: Risk factors for sporadic community-acquired Legionnaires' disease (LD) have been studied in the past, well before the widespread introduction of the urinary antigen test. Our objective was to evaluate the impact of the concomitant decrease in underdiagnosis on established and unknown risk factors for LD., Study Design: Prospective case-control study., Methods: From 1 July 1998 to 30 June 2001, 228 LD cases and 293 controls were included for a national case-control study. Patients were included upon notification provided that they fulfilled international criteria for confirmed LD., Results: A history of diabetes mellitus, current tobacco smoking, travelling abroad, spending one or more nights away from home not leaving the country and being a driver by profession were independent risk factors. LD patients who had travelled abroad during their incubation period differed from LD patients who had not. They appeared healthier than non- or domestic travellers with respect to a history of coronary disease, pulmonary disease, current use of corticosteroids or immunosuppressives and any medication. Also the environmental risk factors differed significantly for the two groups., Conclusions: The finding of two distinct populations of LD patients calls for a differentiated preventive strategy.

Community-acquired legionnaires' disease (CALD) has dramatically increased in the Legionella urinary antigen (LUA) era. However, its incidence in each country depends on the specific techniques used for the diagnosis of LD and the mandatory reporting of cases to the local health surveillance system. Moreover, the most recent studies have demonstrated that no clinical data are discriminative enough for the diagnosis of LD. Clinical differences have been observed in sporadic and outbreak-reported cases demonstrating that the earlier the diagnosis of Legionella infection, the more nonspecific the clinical appearance. Fluoroquinolones are the most efficacious drugs against Legionella. The combination of these drugs with azithromycin seems to be promising in the treatment of patients with severe LD. Although outbreaks of LD will continue, the most important objective of the public health authorities should be to reduce their number and size.

Trinidad and Tobago is an island-state in the Caribbean with a size of 5,128 square kilometers and a population of 1.3 million. Pneumonia is a leading cause of death in Trinidad. This project determined the frequency of Legionella pneumophila in patients with pneumonia, investigated the relationship between pneumonia and selected risk factors. Serum and demographic data were collected from 123 patients, diagnosed with pneumonia. Sera were tested for L pneumophila Ig G/M/A and IgM. All analyses were done using the SPSS statistical package. Of a total of 123 serum samples tested, 39 (31.7) were positive for L pneumophila IgM/G/A while 2 (1.6%) were positive for IgM only. Hospitals, gender and ethnicity did not significantly (p > 0.05; chi-squared) affect the seroprevalence of L pneumophila. Overall, the prevalence of L pneumophila assayed was not significantly (p > 0.05, chi-squared) affected by co-morbidities.