en Microbiology Microbiology Original Article Original Article <span style="font-family:times new roman;"><span style="color:#0000FF;"><strong><em>Background:</em></strong></span> Studies concerning on esophageal squamous cell carcinoma (ESCC) etiological factors have been done for several decades, however, results reported from various investigations were not consistent. The present investigation aimed to explore the presence of 3 oncogenic viruses, human papilloma virus (HPV), Epstein-Barr virus (EBV) and Merkel cell polyomavirus (MCPyV) in the neoplastic and non- neoplastic esophageal lesions collected from Mazandaran, a high risk area of Iran.<br> <span style="color:#0000FF;"><strong><em>Methods:</em></strong></span> In total, 168 esophageal specimens (100 with ESCC confirmed diagnosis and 68 without esophageal malignancy) were analyzed for HPV, EBV and MCPyV by Real Time PCR.<br> <span style="color:#0000FF;"><strong><em>Results:</em></strong></span> HPV DNA was detected in 27 out of the 100 neoplastic esophageal lesions (27.0%) and 28 out of the 68 samples from non-neoplastic group (41.2%). EBV DNA was detected in esophageal specimens of 10 out of the 100 neoplastic cases (10%) and 3 out of the 68 samples in non- neoplastic group (4.4%). MCPyV DNA was detected in esophageal specimens of 30 out of the 100 neoplastic cases (30.0%) and 24 out of the 68 samples in non- neoplastic group (35.3%). There was no statistically significant difference in HPV (p=0.066), EBV (p=0.143) and MCPyV (p=0.471) DNA positivity between neoplastic and non-neoplastic groups.<br> <span style="color:#0000FF;"><strong><em>Conclusions:</em></strong></span> This study showed that HPV, EBV and MCPyV can be detected in both neoplastic and non-neoplastic esophageal tissues and weakens the hypothesis of the pathogenic role of these viruses in esophageal malignant transformation.</span> Esophageal squamous cell carcinoma, Human papillomavirus, Epstein-Barr virus, Merkel cell polyomavirus. 353 360 http://caspjim.com/browse.php?a_code=A-10-941-1&slc_lang=en&sid=1 Yousef Yahyapour u uyahyapoor@yahoo.com 100319475328460014039 100319475328460014039 No Infectious Diseases and Tropical Medicine Research Center, Babol University of Medical Sciences, Babol, Iran Rabeae Rahmani rabe222@yahoo.com 100319475328460014040 100319475328460014040 No Department of Biology, Azad University of Babol, Babol, Iran Majid Alipour alipouryy@gmail.com 100319475328460014041 100319475328460014041 No Department of Biology, Azad University of Babol, Babol, Iran Ahad Alizadeh a-alizadeh@razi.tums.ac.ir 100319475328460014042 100319475328460014042 No Department of Epidemiology and Reproductive Health, Reproductive Epidemiology Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran Aynaz Khademian aynaz1393@gmail.com 100319475328460014043 100319475328460014043 No Department of Microbiology, Babol University of Medical Sciences, School of Medicine, Babol, Iran Farzin Sadeghi sadeghifarzin6@gmail.com 100319475328460014044 100319475328460014044 Yes Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran