Evaluation of the prevalence of Legionella pneumophila in Iranian clinical samples: A systematic review and 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-2 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.