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.

男男性行为者（Men who have sex with men, MSM）是中国台湾地区HIV-1感染的主要高危人群，其监测工作对于HIV-1防控至关重要。本研究于2013至2015年间，在台湾地区北部与南部的17处高危场所及4个社区中心招募MSM群体，开展匿名HIV-1筛查。研究采集血液样本用于基因分型与系统发育分析，并实施涵盖人口统计学变量与社会行为的问卷调查。本研究共计纳入4675名受试者，HIV-1感染率为4.3%（201/4675）。

研究识别出8项与HIV-1感染风险升高显著相关的危险因素：未全程使用安全套者（比值比OR=1.509，P=0.0123）、使用油性润滑剂者（OR=1.413，P=0.0409）以及使用消遣性药物者（OR=2.182，P<0.0001）等。2013至2015年，HIV-1的年感染率与发病率均呈下降趋势：2013年分别为6.56%、每100人年5.97例；2014年为4.53%、每100人年3.97例；2015年为1.84%、每100人年2.08例。全程使用安全套、使用水性润滑剂、掌握润滑剂替代用品的正确知识以及消遣性药物使用等因素，与发病率变化趋势显著相关。

系统发育树分析显示，本地MSM群体的跨区域及国际间互动可能推动了HIV的传播。本次针对高危场所的调查表明，2013至2015年台湾地区HIV-1感染率与发病率均有所下降，这或与行为模式的改变有关。此外，未来的监测工作需将跨区域互动与消遣性药物使用纳入考量范畴。