Type-specific incidence and persistence of HPV infection among young women: a prospective study in North India

Background: Infections with human papillomavirus (HPV) are highly prevalent among sexually active young women in India. However, not much is known about the incidence of type-specific human papillomavirus (HPV) infections and their patterns of persistence, especially in the Indian context. Objective: The objective of this study was to evaluate the rate of acquisition and persistence of HPV types in young women. Methods: Women residing in an urban slum in Delhi (n=1300) were followed for 24 months at 6 monthly intervals. Exfoliated cervical cells collected at each visit were tested for the presence of HPV DNA. Genotyping was performed using the reverse line blot assay. Results: The incidence rate for any HPV type was calculated to be 5 per 1000 women-months. Among high risk HPV types, HPV16 had the highest incidence rate followed by HPV59, HPV52 and HPV18, i.e., 3.0, 0.58, 0.41 and 0.35 women per 1000 women-months respectively. The persistence rate was higher for high-risk than low-risk HPV types. Among low-risk types, HPV42, HPV62, HPV84 and HPV89 were found to persist. Whereas almost all high risk types showed persistence, the highest rate was found in women with HPV types 16, 45, 67, 31, 51 and 59. The persistence rate for HPV16 infection was 45 per 1000 women-months. Conclusion: Incident HPV infections and high risk HPV type-specific persistence were found to be high in our study population of young married women. Understanding the patterns of HPV infection may help plan appropriate strategies for prevention programs including vaccination and screening.