A systematic review and meta-analysis of serotype distribution of Streptococcus pneumoniae in Iran: Practical evidences to optimizing local vaccination protocols
Background: Little is known regarding the burden of predominant circulating serotypes of Streptococcus pneumoniae in Iran. Therefore, this study aimed to investigate the serotype distribution of pneumococcal diseases in Iran by using a comprehensive systematic review of available articles. Methods: A systematic literature search carried out to identify papers published by Iranian authors in the Web of Science, PubMed, Scopus, Embase and Google Scholar electronic databases since January of 2000 to December of 2018. Then, eight publications which met our inclusion criteria were selected for data extraction and analysis by Comprehensive MetaAnalysis software. Results: Totally, three studies reported the distribution of S. pneumoniae serotypes among patients, two studies among healthy individuals, and three studies among both groups. Of those studies, serotype 19A/F (17.9%; 95% CI: 13.6-23.0) was the most circulating serotype followed by 23A/F (12.3%; 95% CI: 7.7-19.2), 6A/B (11.0%; 95% CI: 8.0-14.9), and 14 (8.8%; 95% CI: 5.8-13.2). In contrast, the lowest circulating serotype was 60 (0.02%; 95% CI: 0.0-1.2), 29 (0.07%; 95% CI: 0.01-5.0), and 36 (0.09%; 95% CI: 0.04-2.1). Meta-regression results showed that prevalence of serotype 23A/F significantly increased each year about 0.2% (95% CI: 0.1- 0.3, P <0.001, tau2 <0.001). Conclusion: In the present study, it was found that over the last decade, the most prevalent serotypes in Iran were 19, 23, 6, and 14, respectively. These findings provides practical evidences to select effective pneumococcal vaccine candidates in the prevention of invasive diseases in Iranian patients, and also comparing our situation with others.