UCSF

Objective

HIV-positive MSM are at increased risk of anal human papillomavirus (HPV) infection compared with men in the general population, and little is known about the natural history of anal HPV infection in this population. The objective of this study was to determine the incidence of and risk factors for anal type-specific HPV infection.

Design

Prospective cohort study.

Methods

HIV-positive MSM were evaluated for anal HPV DNA, lifestyle factors, and sexual risk behaviors every 6 months for at least 2 years.

Results

The overall incidence rate of detectable type-specific anal HPV infection was 21.3 per 100 person-years [95% confidence interval (CI) 17.7-25.4] and was 13.3/100 person-years (10.5-16.6) for oncogenic HPV types. The most common incident infections were HPV 18 (3.7/100 person-years) and HPV 16 (3.5/100 person-years). An increased number of recent partners with whom the participant was the receptive partner [odds ratio (OR) 2.9 (1.6-5.1) 8+ partners vs. 0-1], an increased number of new partners in which the participant was the receptive partner [OR 1.03 (1.01-1.1) per partner], an increased number of new oral-anal contact partners in which the participant was the receptive partner [OR 1.1 (1.03-1.1) per partner], and the frequency of receptive anal intercourse [OR 1.1 (1.03-1.1) per act] all significantly increased the odds of incident HPV infection (P ≤ 0.05).

Conclusion

HIV-positive MSM have a high incidence of oncogenic anal HPV infection. Recent receptive anal sexual behaviors, including receptive anal intercourse and receptive oral-anal contact, are the most important risk factors for incident anal HPV infection.