Prevalence of Human Papillomavirus (HPV) and HPV Vaccination Completion Rates Among Gay and Bisexual Men in Dar es Salaam, Tanzania.

High-risk Human Papillomavirus (HPV) is a sexually transmissible virus that causes cancer. Vaccination against HPV is available up to age 45. Gay and bisexual men (GBM) are at high risk for oropharyngeal and anal cancers caused by HPV. As part of a larger study of HPV prevention in GBM, we obtained anal swabs for HPV and offered HPV vaccination to GBM in Dar es Salaam, Tanzania. Participants were recruited by an outreach worker experienced with the GBM subculture using Respondent-Driven Sampling (RDS) from seeds. Eighty-three of a possible one hundred participants (mean age 26) were enrolled, tested, and given a first vaccination dose. Anal swabs were tested for twenty-eight HPV genotypes, both high and low risk for carcinogenicity, and a median of seven different HPV genotypes was found in participants. A total of 87% of participants carried at least one HPV genotype, and 76% carried at least one high-risk genotype. As a result of harassment and unanticipated risk to participants and staff at the unmarked community-based site, this study was terminated before the sample size was reached. Since a full course of vaccine was the standard of care, participants were contacted using the contact method they had provided to arrange follow-up vaccination doses at an alternative clinical site. Twenty-nine percent received the additional vaccination. A further 6% made appointments but did not attend, and another 10% would have received the second vaccination if they were incentivized to attend. The rate of HPV in anal samples was significantly higher than in our study using the same recruitment method in the same city in 2011-2012. The HIV rate was 45%. Anal HPV rates, including high-risk HPV rates, were significantly higher than in a similar population of gay and bisexual men 12 years ago. It is possible to provide HPV vaccination to gay and bisexual men in Tanzania and have approximately 45% potentially re-attend for a second dose if they are incentivized. Great care must be used to situate vaccination to avoid stigma leading to harassment, especially where homosexuality is criminalized. We infer that the high-risk harassment faced by participants and lack of incentive for the second visit depressed the return rate for revaccination.