Prevalence and characterization of Blastocystis spp. in central southwest of Iran

Blastocystis is one of the most common intestinal protozoan parasites of human all over the world. Due to high prevalence and widespread species diversity of this parasite and the possibility of potential transmission of them to human, this study was carried out to investigate the prevalence of Blastocystis and characterize its subtypes (genotypes) in Shahrekord, central southwest of Iran. Microscopic examination showed that 6.4% (55/864) of the subjects were infected with Blastocystis spp. All of positive samples were sequenced successfully. The molecular methods showed that the infection was caused by four subtypes, including ST1, ST2, ST3 and ST7. The most common identified genotype of Blastocystis was ST3 (36.4%). The statistical analysis of data showed that there was no significant correlation between the prevalence of Blastocystis or its subtypes with age, gender, job, level of education, contact with animals, and clinical manifestations of infection in the patients. While the frequency of blastocystosis in this population seems to be less than many parts of Iran, but it can be argued that Blastocystis is still the most common intestinal parasite of human in this region compared with other intestinal parasites and it seems that the transmission of infection has an anthroponotic pattern.