Prevalence and Genotype Characterization of Blastocystis hominis Among the Baghmalek People in Southwestern Iran in 2013 - 2014

Blastocystis hominis is a common globally distributed parasite. The prevalence of this parasite has been shown to vary among different countries. Molecular studies have also shown that there is a high level of genetic diversity among Blastocystis spp. isolated from humans and animals. Extensive information on parasitic genotypes will aid in devising more effective strategies for the identification and potential control of these pathogenic parasites. This study aimed to gain information on the prevalence and abundance of Blastocystis subtypes in Iran. Over a period of 3 months, 1,410 stool samples were collected and examined by microscopy. Samples found to be positive for B. hominis were concentrated and phylogenetic analysis was subsequently performed. A questionnaire was completed by all study participants. Blastocystis hominis was found to have a prevalence of 3.33% in the study population. There was no significant association of Blastocystis infection with age (P = 0.3) or gender (P = 0.57). The Blastocystis subtypes (ST) identified in this study were ST3, ST4, ST5, and ST7 with the most prevalent being ST4 (40.9%). The prevalence of B. hominis in the study area was lower than that reported for most developed countries, and unlike in other countries in the Middle East, ST4 was the most prevalent subtype.