UC Berkeley

Abstract

Human papillomavirus infection in HIV-seropositive men who have sex with men in both the United States and India:

Prevalence, incidence, and risk factors for infection

by

Alexandra Lydia Hernandez

Doctor of Philosophy in Epidemiology

University of California, Berkeley

Professor Arthur Reingold, Chair

Human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) are at high risk of anal cancer compared with the general population. Human papillomavirus (HPV) infection, particularly HPV 16, causes anal cancer. The prevalence of anal HPV infection among HIV-infected men in the US is >90% but little is known about the risk factors for prevalence, and incidence of or the risk factors for type-specific anal HPV infection . There is also limited knowledge about anal HPV infection among HIV-infected MSM in India, although the background incidence of HPV-related cancers in both men and women is high in India. Indian HIV-infected MSM may be at especially high risk for anal HPV infection and HPV-associated disease.

My aim was to determine the prevalence and incidence of and risk factors for anal HPV infection among two populations of HIV-infected MSM, one from San Francisco and the second from India. The San Francisco population was two-year longitudinal study and allowed for both prevalence and incidence analysis; the India study was cross-sectional in design and allowed only for a prevalence analysis.

The prevalence of anal HPV infection among HIV-infected MSM in San Francisco was 92%, 80% had oncogenic types and 42% had HPV 16. A higher number of total life-time partners was associated with increased prevalence of HPV 16. The incidence of any anal HPV infection was 21.3 per 100 person-years (PY) and 3.5/100 for HPV 16. A higher number of recent partners with whom the participant was the receptive partner was associated with a higher incidence of any anal HPV infection. New receptive partners, more frequent receptive sex, and new oral-anal contact partners was also associated with a higher incidence of any anal HPV infection. The prevalence of anal HPV infection among HIV-infected Indian MSM was 71%, and ever having receptive anal intercourse and higher number of receptive partners increased prevalence. "Almost always" condom use with receptive anal intercourse decreased prevalence of anal HPV infection among HIV-infected Indian MSM.

In conclusions, HIV-infected MSM in both San Francisco and India have high prevalences of anal HPV infection and the incidence of anal HPV among these men in San Francisco is also high. The most important risk factors for infection are total number of male partners and receptive anal intercourse. Condoms may protect against anal HPV infection, but further research is needed to confirm results. HIV-infected MSM should be counseled on safe sex practices with all partners and encouraged to receive the recently recommended HPV vaccine.