High prevalence of HIV infection and unprotected anal intercourse among older men who have sex with men in China: a systematic review and meta-analysis.

Background China has the largest number of the elderly in the world. As the proportion of elderly is rapidly increasing among national reported HIV/AIDS cases, it is a concern about HIV epidemic among older MSM in China. However, studies on HIV prevalence and unprotected anal intercourse (UAI) among Chinese older MSM were relatively few or generally had small sample sizes.