Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 8 1 2013 03 15 60 64 EN S Heidary Dept. of Parasitology and Mycology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. M Bandehpour Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran AND Dept. of Biotechnology, Shahid Beheshti University of Medical Sciences, Tehran, Iran Z Valadkhani Dept. of Parasitology, Pasteur Institute of Iran, Tehran, Iran Sj Seyyed-Tabaee Dept. of Parasitology and Mycology, Shahid Beheshti University of Medical Sciences, Tehran, Iran A Haghighi Dept. of Parasitology and Mycology, Shahid Beheshti University of Medical Sciences, Tehran, Iran Ar Abadi Dept. of Social Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran B Kazemi Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran AND Dept. of Biotechnology, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2015 10 14   Background: Trichomonas vaginalis is a pathogenic protozoon and may be contaminated with dsRNA virus called Trichomonas vaginalis virus (TVV). The viral infection is an important factor for its patho-genesis and sensitivity to metronidazole. The presence of TVV is associated with qualitative and quantitative expression of cysteine proteinases and surface immunogenic; P270. The purpose of this study was to determine TVV frequency in T. vaginalis clinical isolates in Tehran, Iran. Methods:The 46 T. vaginalis isolates were collected from Tehran Province and cultured in TYI-S-33 culture medium. Viral RNA was extracted and RT-PCR was done. Results:Of 46 T. vaginalis isolates, 8 isolates (17.39%) were infected with TVV-1. There was not any association between patient age and TVV- infected T. vaginalis. There were 17.39% viral infection in T. vaginalis isolates which was lower than that reported by other researchers. Conclusion:This is the first report on T. vaginalis isolates infection by TVV-1 in Iran. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/525 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/525/392