Samaneh Abdolahi - Graduate of Parasitology, Faculty of medical science, Tarbiat Modares University, Tehran, Iran.
Abdolhossein Dalimi - Department of medical Parasitology and Entomology, Faculty of Medical Sciences, Tarbiat Modares University
Majid Piranestani - Department of medical Parasitology, Faculty of Medical Sciences, Tarbiat Modares University

Aims: Blastocystis is a common intestinal parasite among humans and various animals, including birds. The parasite has at least ۲۸ known subtypes, of which nine subtypes have been reported in humans and livestock. The aim of this study was to determine the prevalence rate and common subtypes of Blastocystis hominis in pigeons and their owners in Tafresh city. Materials & Methods: The present study was designed and conducted as a case control in Tafresh city (Markazi province) during ۲۰۲۰-۲۰۲۱. For this purpose, fecal samples were collected from pigeons (۳۰۰ samples) and their owners (۱۰۰ samples). Stool samples were studied by microscopic methods (direct and trichrome staining examinations). Then positive stool samples were examined by PCR method through amplification of ۱۸ SrRNA gene and sequencing. Findings: In direct stool examination, ۳۹ (۱۳%) out of ۳۰۰ pigeon samples and ۱۸ (۱۸%) out of ۱۰۰ human fecal samples were found to be positive for Blastocystis. In trichrome staining method, ۱۸% of human samples and ۱۵% of pigeon samples were positive, while in PCR test, only ۲.۵% of pigeon samples and ۴.۵% of human samples were Blastocystis positive. The alignment results showed that all Blastocystis strains isolated in this study (۱۰۰%) were similar to subtype ۳. Conclusion: Due to the low prevalence rate of this parasite in pigeons in Tafresh city, their owners are less likely to be infected with this parasite. Therefore, the relative transmission risk of this parasite from pigeons to humans is low.

Blastocystis, Human, Pigeon, Subtype, Tafresh