Persistence and risk factors of high-risk human papillomavirus infection among HIV positive and HIV negative tanzanian women: a cohort study.

BACKGROUND

High-risk (HR) human papillomavirus (HPV) persistence is the most important risk factor for cervical cancer. We have assessed the type-specific HR HPV persistence among HIV positive and HIV negative Tanzanian women and factors associated with HR HPV persistence.

METHODS

In a cohort study including 4080 Tanzanian women, 3074 attended follow-up examination (up to 32 months after enrollment). Cervical samples were obtained for liquid-based cytology and HPV DNA testing using Hybrid Capture 2 and Inno-Lipa Extra II. Information on lifestyle factors was collected through a personal interview. The probability of HR HPV persistence at a given time point since enrollment was estimated non-parametrically using the EMICM algorithm.

RESULTS

Among the 462 women HR HPV positive at enrollment, 158 had at least one identical type detected at follow-up. The probability of persistence at 18 months after enrollment was 34.2 (95% CI 29.0-39.4). Stratifying by HIV status, the persistence probability was 42.9% (95% CI 33.5-51.9) among HIV positive, and 28.0% (95% CI 22.1-34.2) among HIV negative. Overall, HR HPV persistence was most common for HPV58, 35, 16, 31, and 52. Among HIV positive women it was HPV45, and HPV16, followed by HPV58 and HPV18, and among HIV negative women it was HPV31, HPV33 and HPV58. Risk factors associated with persistence of HR HPV were older age, longer interval between enrollment and follow-up, binge drinking, and HIV status.

CONCLUSIONS

HR HPV persistence was common in Tanzania, and most common among HIV positive women. Overall, persistence was most frequent for HPV 58, 35, 16, 31 and 52. The nonavalent HPV vaccine should be considered.