Human papilloma and other DNA virus infections of the cervix: A population based comparative study among tribal and general population in India

BACKGROUND: Despite being preventable, cervical cancer remains a major health concern among women. Persistent Human Papillomavirus (HPV) and other viral co-infections may influence cervical dysplasia. We determined and compared the prevalence and risk factors of cervical viral infections among the tribal and general population of southern coastal Karnataka, India. METHODS: A population-based cross-sectional survey was conducted among 1140 and 1100 women from tribal and general population, respectively. Cervical infections with HPV, Epstein-Barr Virus (EBV), Cytomegalovirus (CMV) and Herpes-Simplex Virus (HSV) were examined using polymerase chain reactions (PCR) and DNA sequencing. RESULTS: HPV prevalence was higher among tribal women (40.6%) than general population (14.3%) while the prevalence of EBV (55.1%) and CMV (49.4%) were lower among tribal women than general population (74.3% and 77.5%, respectively). HSV infection was observed in tribal women only (1.8%). Among HR-HPV strains, HPV-18 was predominant among tribal population (28.3%) while, HPV-16 was predominant among the general population (9.1%). Infections were associated with age, educational status, unemployment and personal hygiene of tribal women. Phylogenetic analysis revealed that HPV-16 variants of tribal participants were closely related to non-European sublineages indicating greater risk of HPV persistence and carcinogenesis. CONCLUSION: The study provides a comparative estimate for DNA virus infections of the cervix among women from general as well as tribal population in this region and also reveals a different type-specific pattern of viral infection. Further research is required to delineate the role of specific interactions between multiple virus infections and their role in carcinogenesis.