Prevalence and genotype analysis of Blastocystis hominis in Iran: A systematic review and meta-analysis

Abstract

Context: Blastocystis hominis is a unicellular protozoan found commonly in the intestinal tract of humans and many other animals with multiple subtypes, which tend to be specific to the host. We aimed to apply a meta-analysis for studies of protozoan pathogens in order to obtain a general overview of the prevalence and genotype analysis of Blastocystis spp. in Iran. Evidence Acquisition: International electronic databases such as PubMed, Scopus, ISIWeb of Science, Ovid, Google scholar, and national databases including SID, Iranmedex and Magiran were searched from 2003 to 2015 for studies that reported the prevalence of B. hominis in Iran. We calculated prevalence estimates with 95% CIs and assessed heterogeneity between studies using the I2 statistic and the Cochran Q test. Results: We included 40 eligible studies in this review. The pooled prevalence of Blastocystis hominis was 3% (95% CI: 3 - 3). Conclusions: Unlike the world, a ST5 subtype of human cases is common and the reservoir seems to be cattle. ST2 has been found in birds in Iran. Further studies are needed to confirm these important findings and to clarify the possible pathogenesis and reveal whether this is an exception or the rule.