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Microbial Pathogenesis Apr 2019Legionella pneumophila is the main cause for community-acquired pneumonia especially in hospital environments. In this systematic review and meta-analysis, we evaluated... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Legionella pneumophila is the main cause for community-acquired pneumonia especially in hospital environments. In this systematic review and meta-analysis, we evaluated the prevalence of L. pneumophila in clinical samples obtained from Iranian patients.
METHODS
The studies reporting L. pneumophila prevalence in Iranian clinical samples that were published between January 2000 and July 2016 were recruited. Comprehensive Meta-Analysis Software (version 3.3.070) was used for quantitative data analysis. Because of high heterogeneity between the studies according to the Cochrane Q and I statistics, a random-effects model was used for meta-analysis.
RESULTS
Sixteen studies encompassing 1956 subjects were included in the meta-analysis. The overall prevalence of L. pneumophila was 9.6% in clinical samples obtained from the Iranian patients. The age spectrum ranged from 6 months to 80 years old. Dyspnea and cough comprised the most common clinical manifestations. In the subgroup analysis, the prevalence of L. pneumophila was higher in studies with sample size ≤100 (12.9%) in comparison with studies with sample size >100 (8.4%). In addition, the prevalence of L. pneumophila was higher in the years 2009-2016 (9.2%) compared with 2000-2008 (0.7%).
CONCLUSION
L. pneumophila is a major cause of community- and hospital-acquired pneumonia. It is of pivotal importance to implement sensitive and reliable molecular and culture-based techniques to detect and control this infection in healthcare environments.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Community-Acquired Infections; Cross Infection; Female; Humans; Infant; Iran; Legionella pneumophila; Legionnaires' Disease; Male; Middle Aged; Prevalence; Young Adult
PubMed: 30738817
DOI: 10.1016/j.micpath.2019.02.008 -
International Journal of Environmental... Jul 2018spp. is widespread in many natural and artificial water systems, such as hot water distribution networks, cooling towers, and spas. A particular risk factor has been...
spp. is widespread in many natural and artificial water systems, such as hot water distribution networks, cooling towers, and spas. A particular risk factor has been identified in the use of whirlpools and hot tubs in spa facilities and public baths. However, there has been no systematic synthesis of the published literature reporting legionellosis cases or outbreaks related to swimming/spa pools or similar environments used for recreational purposes (hot springs, hot tubs, whirlpools, natural spas). This study presents the results of a systematic review of the literature on cases and outbreaks associated with these environments. Data were extracted from 47 articles, including 42 events (17 sporadic cases and 25 outbreaks) and 1079 cases, 57.5% of which were diagnosed as Pontiac fever, without any deaths, and 42.5% were of Legionnaires' disease, with a fatality rate of 6.3%. The results are presented in relation to the distribution of species involved in the events, clinical manifestations and diagnosis, predisposing conditions in the patients, favourable environmental factors, and quality of the epidemiological investigation, as well as in relation to the different types of recreational water sources involved. Based on the epidemiological and microbiological criteria, the strength of evidence linking a case/outbreak of legionellosis with a recreational water system was classified as strong, probable, and possible; in more than half of the events the resulting association was strong.
Topics: Balneology; Disease Outbreaks; Health Resorts; Hot Springs; Humans; Legionellosis; Swimming Pools; Water Microbiology
PubMed: 30061526
DOI: 10.3390/ijerph15081612 -
Journal of Medical Microbiology Apr 2017Rapid and effective diagnosis of Legionnaires' disease (LD) cases is extremely important so that timely and appropriate therapy can be provided, thereby lowering the... (Review)
Review
PURPOSE
Rapid and effective diagnosis of Legionnaires' disease (LD) cases is extremely important so that timely and appropriate therapy can be provided, thereby lowering the morbidity and mortality rates and reducing the health and economic costs associated with this disease.
METHODOLOGY
Diagnosis is established solely by microbiological tests. There are several methods available, each with different performance, sensitivity and specificity characteristics, and further understanding is required. Our objective was to assess the accuracy of urinary antigen detection, direct fluorescent antibody (DFA) staining, serological testing and the polymerase chain reaction (PCR) method versus culture analysis (the reference standard) in patients suspected of being infected with Legionella or patients with laboratory-confirmed LD. We performed a MEDLINE search in November 2014. Two authors independently assessed the trials and extracted data. Pooled analysis was performed through Meta-DiSc version 1.4.
RESULT
The inclusion criteria were met by 11 studies. All the studies evaluated PCR and DFA tests to detect Legionella in clinical specimens, comparing them to culture techniques, and were included in the meta-analysis. The pooled sensitivity and specificity for PCR were 83 % [95 % confidence interval (CI): 79-87 %] and 90 % (95 % CI: 88-92 %), respectively. DFA was evaluated in one study and the sensitivity and specificity of this test were 67 % (95 % CI: 30-93 %) and 100 % (95 % CI: 91-100 %), respectively. PCR had high sensitivity and specificity for early diagnosis of LD.
CONCLUSION
Culture analysis is deemed necessary for epidemiological studies, molecular strain typing and antibiotic sensibility evaluations; however, the performance of PCR in recent studies calls for additional, well-designed studies in order to achieve the best standard test, which will enable optimization of the Legionella infection diagnostic.
Topics: Antigens, Bacterial; Diagnostic Tests, Routine; Fluorescent Antibody Technique, Direct; Humans; Legionnaires' Disease; Polymerase Chain Reaction; Sensitivity and Specificity
PubMed: 28463665
DOI: 10.1099/jmm.0.000454 -
American Journal of Infection Control Nov 2016Legionnaires' disease (LD) is recognized as an important hospital-acquired disease. Despite the several methods available, the optimal method to control... (Review)
Review
Are there effective interventions to prevent hospital-acquired Legionnaires' disease or to reduce environmental reservoirs of Legionella in hospitals? A systematic review.
BACKGROUND
Legionnaires' disease (LD) is recognized as an important hospital-acquired disease. Despite the several methods available, the optimal method to control hospital-acquired LD is not well established and their overall efficacy requires further evaluation.
OBJECTIVE
To systematically review all controlled trials evaluating the efficacy of interventions to prevent hospital-acquired LD in patients at high risk of developing the disease and its effects on environmental colonization.
METHODS
A database search was performed through PubMed and the Cochrane Central Register of Controlled Trials (inception-November 2014). Eligible studies included all controlled studies evaluating interventions to prevent hospital-acquired LD in patients at high risk or evaluating the effect on environmental colonization. Both individual and pooled risk estimates were reported using risk ratio (RR) and 95% confidence intervals (95% CIs).
RESULTS
There were no studies evaluating the risk reduction in hospital-acquired LD, but 4 studies evaluated the influence of copper-silver ionization and ultraviolet light in the reduction of environmental reservoirs of Legionella. The meta-analysis showed a significant 95% risk reduction of Legionella positivity in environmental samples using copper-silver ionization (RR, 0.05; 95% CI, 0.01-0.17) and 97% risk reduction with ultraviolet light (RR, 0.03; 95% CI, 0.002-0.41).
CONCLUSIONS
The best available evidence suggests that copper-silver ionization and ultraviolet light are effective in reducing Legionella positivity in environmental samples. Nevertheless, the low quality of evidence weakens the robustness of conclusions.
Topics: Copper; Cross Infection; Disinfectants; Environmental Microbiology; Hospitals; Humans; Infection Control; Legionella; Legionnaires' Disease; Silver
PubMed: 27524259
DOI: 10.1016/j.ajic.2016.06.018 -
Journal of Clinical Microbiology Feb 2016The diagnosis of Legionnaires' disease (LD) is based on the isolation of Legionella spp., a 4-fold rise in antibodies, a positive urinary antigen (UA), or direct... (Meta-Analysis)
Meta-Analysis Review
The diagnosis of Legionnaires' disease (LD) is based on the isolation of Legionella spp., a 4-fold rise in antibodies, a positive urinary antigen (UA), or direct immunofluorescence tests. PCR is not accepted as a diagnostic tool for LD. This systematic review assesses the diagnostic accuracy of PCR in various clinical samples with a direct comparison versus UA. We included prospective or retrospective cohort and case-control studies. Studies were included if they used the Centers for Disease Control and Prevention consensus definition criteria of LD or a similar one, assessed only patients with clinical pneumonia, and reported data for all true-positive, false-positive, true-negative, and false-negative results. Two reviewers abstracted data independently. Risk of bias was assessed using Quadas-2. Summary sensitivity and specificity values were estimated using a bivariate model and reported with a 95% confidence interval (CI). Thirty-eight studies were included. A total of 653 patients had confirmed LD, and 3,593 patients had pneumonia due to other pathogens. The methodological quality of the studies as assessed by the Quadas-2 tool was poor to fair. The summary sensitivity and specificity values for diagnosis of LD in respiratory samples were 97.4% (95% CI, 91.1% to 99.2%) and 98.6% (95% CI, 97.4% to 99.3%), respectively. These results were mainly unchanged by any covariates tested and subgroup analysis. The diagnostic performance of PCR in respiratory samples was much better than that of UA. Compared to UA, PCR in respiratory samples (especially in sputum samples or swabs) revealed a significant advantage in sensitivity and an additional diagnosis of 18% to 30% of LD cases. The diagnostic performance of PCR in respiratory samples was excellent and preferable to that of the UA. Results were independent on the covariate tested. PCR in respiratory samples should be regarded as a valid tool for the diagnosis of LD.
Topics: Antigens, Bacterial; Humans; Immunologic Tests; Legionella; Legionellosis; Polymerase Chain Reaction; Publication Bias; Reproducibility of Results; Sensitivity and Specificity
PubMed: 26659202
DOI: 10.1128/JCM.02675-15 -
Journal of Travel Medicine 2015Travel-associated Legionnaires' disease (LD) is a serious problem, and hundreds of cases are reported every year among travelers who stayed at hotels, despite the... (Review)
Review
BACKGROUND
Travel-associated Legionnaires' disease (LD) is a serious problem, and hundreds of cases are reported every year among travelers who stayed at hotels, despite the efforts of international and governmental authorities and hotel operators to prevent additional cases.
METHODS
A systematic review of travel-associated LD events (cases, clusters, outbreaks) and of environmental studies of Legionella contamination in accommodation sites was conducted. Two databases were searched (PubMed and EMBASE). Data were extracted from 50 peer-reviewed articles that provided microbiological and epidemiological evidence for linking the accommodation sites with LD. The strength of evidence was classified as strong, possible, and probable.
RESULTS
Three of the 21 hotel-associated events identified and four of nine ship-associated events occurred repeatedly on the same site. Of 197 hotel-associated cases, 158 (80.2%) were linked to hotel cooling towers and/or potable water systems. Ship-associated cases were most commonly linked to hot tubs (59/83, 71.1%). Common contributing factors included inadequate disinfection, maintenance, and monitoring; water stagnation; poor temperature control; and poor ventilation. Across all 30 events, Legionella concentrations in suspected water sources were >10,000 cfu/L, <10,000 cfu/L, and unknown in 11, 3, and 13 events, respectively. In five events, Legionella was not detected only after repeated disinfections. In environmental studies, Legionella was detected in 81.1% of ferries (23/28) and 48.9% of hotels (587/1,200), while all 12 cruise ships examined were negative.
CONCLUSIONS
This review highlights the need for LD awareness strategies targeting operators of accommodation sites. Increased standardization of LD investigation and reporting, and more rigorous follow-up of LD events, would help generate stronger, more comparable evidence on LD sources, contributing factors, and control measure effectiveness.
Topics: Disease Outbreaks; Humans; Legionella pneumophila; Legionnaires' Disease; Risk Factors; Ships; Travel
PubMed: 26220258
DOI: 10.1111/jtm.12225 -
The Journal of Antimicrobial... Sep 2014Legionellosis is a life-threatening disease. The clinical superiority of quinolones or macrolides for treating patients with legionellosis has not been established. (Comparative Study)
Comparative Study Meta-Analysis Review
BACKGROUND
Legionellosis is a life-threatening disease. The clinical superiority of quinolones or macrolides for treating patients with legionellosis has not been established.
METHODS
We performed a systematic review and meta-analysis of studies reporting data that allowed the comparison of quinolones versus macrolides in the treatment of proven legionellosis published from 1 January 1985 to 31 January 2013. We collected baseline aggregate patient characteristics. Studied outcomes included mortality, clinical cure, time to apyrexia, length of hospital stay and occurrence of complications in each treatment group. Treatment effect was assessed using a Mantel-Haenszel random effects model.
RESULTS
Among 1005 abstracts reviewed, 12 studies were selected (n=879 patients). No randomized controlled trial was performed directly comparing quinolone and macrolide efficacy in legionellosis. Mean age was 58.3 years, 27.7% were women and Fine score was ≥ 4 in 35.8%. Among 253 patients who received quinolone monotherapy, 10 died (4.0%). Among 211 patients who received macrolide monotherapy, 23 died (10.9%). The pooled OR of death for treatment with a quinolone versus a macrolide was 0.5 (95% CI 0.2-1.3, n=8 studies, 464 patients). Length of stay was significantly shorter in the quinolone monotherapy group. The difference was 3.0 days (95% CI 0.7-5.3, P=0.001, n=3 studies, 263 patients). Neither of two tests for heterogeneity was significant (I (2)=0% for both, P=1). Other studied outcomes were not significantly different among treatment groups.
CONCLUSIONS
Few clinical data on legionellosis treatment are available. This first meta-analysis showed a trend toward a lower mortality rate and a significant decrease in length of hospital stay among patients receiving quinolones. These results must be confirmed by a randomized controlled trial.
Topics: Anti-Bacterial Agents; Humans; Legionellosis; Length of Stay; Macrolides; Quinolones; Survival Analysis; Treatment Outcome
PubMed: 24827889
DOI: 10.1093/jac/dku159 -
Current Opinion in Infectious Diseases Apr 2010Legionella pneumophila is increasingly recognized as a significant cause of sporadic and epidemic community-acquired and nosocomial-acquired pneumonia. This review... (Review)
Review
PURPOSE OF REVIEW
Legionella pneumophila is increasingly recognized as a significant cause of sporadic and epidemic community-acquired and nosocomial-acquired pneumonia. This review focuses on the latest literature concerning the epidemiology, pathogenesis, clinical presentation, diagnosis, and treatment of Legionnaires' disease.
RECENT FINDINGS
A significant increase in the incidence of Legionnaires' disease in the United States has been documented over the last years. L. pneumophila has recently been found to be a leading cause of community-acquired pneumonia in hospitalized and ambulatory patients in Germany. Recent studies provide insight into the understanding of the pathogenesis of Legionnaires' disease and the relevance of the formation of biofilms. Clinical manifestations of Legionnaires' disease are not specific and current diagnostic scores are of limited use. Several recent studies offer useful information concerning Legionnaires' disease in immunosuppressed patients. A systematic review of English literature performed to assess test characteristics of Legionella urinary antigen has found that the pooled sensitivity of the test was 0.74 and specificity was 0.991. Improved clinical response has been observed for patients with Legionnaires' disease treated with highly active antimicrobial agents against Legionella.
SUMMARY
Legionnaires' disease is a significant health problem in many countries. Clinical manifestations are unreliable in diagnosing Legionnaires' disease. Therefore, diagnostic laboratory tests for Legionella, including the urinary antigen test, should be applied to all patients with pneumonia. Levofloxacin (or other fluoroquinolone) or azithromycin are the current drugs of choice for treatment of Legionnaires' disease. Effective preventive strategies are needed.
Topics: Anti-Bacterial Agents; Antigens, Bacterial; Azithromycin; Community-Acquired Infections; Cross Infection; Germany; Humans; Incidence; Legionella pneumophila; Legionnaires' Disease; Levofloxacin; Ofloxacin; United States
PubMed: 20051846
DOI: 10.1097/QCO.0b013e328336835b -
Chest Dec 2009Urinary antigen assays offer simplicity and rapidity in diagnosing Legionnaires' disease, though studies report a range of sensitivities. We conducted a systematic... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Urinary antigen assays offer simplicity and rapidity in diagnosing Legionnaires' disease, though studies report a range of sensitivities. We conducted a systematic review to assess the test characteristics of Legionella urinary antigen.
METHODS
We searched Medline, Excerpta Medica Database, and bibliographies of retrieved articles. English-language studies were used and included if the absolute number of true-positive, false-negative, true-negative, and false-positive observations were available, and the "gold standards" were described clearly. Two investigators independently reviewed articles and extracted data. Quality was assessed with the Quality Assessment for Diagnostic Accuracy Studies (QUADAS). Sensitivities and specificities were pooled using a random-effects model weighted with the inverse of the SE calculated through the Wald method.
RESULTS
Fifty articles were retrieved for detailed evaluation, and 30 met the inclusion criteria. All but two studies focused on serotype 1 Legionella. Forty assays were reported using six different methodologies, whereas 26 assays used commercial tests, and 14 assays used in-house tests. Study quality was generally low, with average QUADAS scores of 4.4 of a total of 14 points (range, 1 to 9 points). The pooled sensitivity was 0.74 (95% CI, 0.68 to 0.81), and the specificity was 0.991 (95% CI, 0.984 to 0.997). Higher quality studies had lower sensitivity, and there was evidence of publication bias.
CONCLUSIONS
Legionella urinary antigen for serotype 1 appears to have excellent specificity, though modest sensitivity. However, the poor quality of the included studies and the presence of publication bias suggest an overestimation of test performance. High-quality studies are needed.
Topics: Antigens, Bacterial; Humans; Legionella; Legionellosis; Sensitivity and Specificity; Urinalysis
PubMed: 19318671
DOI: 10.1378/chest.08-2602