Anal Human Papillomavirus Genotyping among HIV-Positive Men Who Have Sex with Men in Xi'an, China.

Background Anal human papillomavirus (HPV) infection and its related diseases are relatively common in men who have sex with men (MSM), especially in those HIV positive. In China, molecular epidemiology of anal HPV infection among HIV-positive MSM has been sparsely studied. Methods A cross-sectional study was conducted among HIV-positive MSM in Xi’an, China between April and July 2014. Anal swabs were collected for HPV genotyping. Results A total of 195 HIV-positive MSM were included in this study. HPV genotyping showed that 99.0% (191/193) of participants were positive for at least one of the targeted 37 HPV genotypes. 183 (94.8%) of them were infected with multiple high-risk types and 154 (79.8%) of them with low-risk HPV types. HPV 18 was the most frequently identified high-risk type, followed by HPV 16 and HPV 51. As for low-risk types, HPV11, HPV 6 and HPV 81 were most commonly observe. High-risk HPV infection was found to be associated with the status of antiretroviral therapy (ART), the distribution of low-risk types was observed to be varied by CD4+ T cell level. Conclusion Almost all HIV-positive MSM were anal HPV infected in our study. It is highly recommended to consider regular active screening and preventive intervention of HPV infection among this high risk population.