Molecular epidemiology of HIV-1 infection among men who have sex with men in Taiwan from 2013 to 2015.

Men who have sex with men (MSM) is the major risk population of HIV-1 infection in Taiwan, and its surveillance has become critical in HIV-1 prevention. We recruited MSM subjects from 17 high-risk venues and 4 community centers in northern and southern Taiwan for anonymous HIV-1 screening during 2013-2015. Blood samples were obtained for genotyping and phylogenetic analysis, and a questionnaire survey covering demographic variables and social behavior was conducted. In total, 4,675 subjects were enrolled, yielding a HIV-1 prevalence rate of 4.3% (201/4675). Eight risk factors including subjects who did not always use condoms (OR = 1.509, p = 0.0123), those who used oil-based lubricants (OR = 1.413, p = 0.0409), and those who used recreational drugs (OR = 2.182, p = < .0001) had a higher risk of HIV-1 infection. The annual prevalence and incidence of HIV-1 showed a downward trend from 2013 to 2015 (6.56%, 5.97 per 100 person-years in 2013; 4.53%, 3.97 per 100 person-years in 2014; 1.84%, 2.08 per 100 person-years in 2015). Factors such as always using condoms, water-based lubricant use, correct knowledge of lubricating substitutes, and recreational drug use were significantly associated with the trend of incidence. Phylogenetic tree analysis showed that the cross-regional and international interaction of the local MSM population may have facilitated transmission of HIV. This survey of high-risk venues showed decreased prevalence and incidence of HIV-1 infection in Taiwan from 2013 to 2015, and this may be related to changes in behavioral patterns. Moreover, cross-regional interaction and recreational drug use need to be considered in future surveillance.