Subtype distribution of Blastocystis sp. isolated from humans in Iran: a systematic review and meta-analysis.

Abstract

This systematic review and meta-analysis evaluated the subtyped Blastocystis sp. isolated from humans in Iran. Blastocystis sp. is an anaerobic intestinal protozoan that infects humans as well as domestic and wild animals, i.e. mammals, amphibians, reptiles, and arthropods. A comprehensive search for papers published before April 2022 was undertaken utilizing English and Persian databases. The following MeSH keywords were used in the electronic search: (Blastocystis sp.) AND (molecular OR subtype) AND (prevalence OR epidemiology) AND Iran. The quality of the included studies was evaluated. Thereafter, a random-effects meta-analysis was conducted to estimate the pooled prevalence and odds ratios regarding the included studies. A total of 32 studies comprised of five case-control studies and 27 cross-sectional studies met the eligibility criteria. The overall pooled prevalence of subtyped Blastocystis sp. in Iran was estimated to be 10% (95% confidence interval: 6 to 15%). Eight subtypes of Blastocystis sp. (ST1- ST7 and ST9) were identified in our study, of which ST3 was the most common subtype (0.04); 0.02-0.07). The difference in subtypes between two case and control groups in reported studies was not significant, but the odds ratio of infection by ST3 (0.98; 95% CI, 0.30 to 3.20) was higher in cases. The current systematic review showed that with the exception of ST8 and ST12, all human Blastocystis sp. subtypes reported in the world are found in different parts of Iran.