Irvin Risha, Vallabhaneni Snigdha, Scott Hyman, Williams John K, Wilton Leo, Li Xin, Buchbinder Susan
Division of Infectious Diseases, Johns Hopkins University, Baltimore, Maryland, United States of America; Bridge HIV, San Francisco Department of Public Health, San Francisco, California, United States of America.
Center for AIDS Prevention Studies, University of California San Francisco, San Francisco, California, United States of America.
PLoS One. 2015 Feb 17;10(2):e0118281. doi: 10.1371/journal.pone.0118281. eCollection 2015.
Seroadaptation is defined as the practice of modifying sexual behavior based on one's own HIV serostatus, the perceived HIV serostatus of sexual partners, and differences in risk of HIV transmission by sexual acts. Because this definition implies intent, we use the term "seroprotection" to describe HIV negative participants reporting condomless anal sex (CAS) either exclusively with seronegative partners, or only as the insertive partner with HIV positive or unknown serostatus partners. Little is known about seroprotection in Black men who have sex with men (MSM). We evaluated the independent association of seroprotection and HIV acquisition among the 1144 HIV-negative Black MSM enrolled in HPTN 061 using Cox models; we stratified by city of enrollment, and controlled for number of partners, age, and drug use. Behaviors reported at 0, 6, and 12 months were assigned to three mutually exclusive categories: (1) No CAS; (2) Seroprotection; and (3) CAS without seroprotection. In 2,861 six-month intervals; 28 HIV seroconversions occurred. No CAS was reported at 33.3% of visits, seroprotection at 46.6% of visits, and CAS without seroprotection at 20.1% of visits. The seroconversion rate per 100 person-years for no CAS was 0.98 (95% CI: 0.27, 2.51), compared with 2.39 (95% CI: 1.03, 4.71) and 13.33 (95% CI: 7.62, 21.66) for seroprotection and CAS without seroprotection, respectively. Compared to CAS without seroprotection, intervals without CAS were associated with an 87% reduction (aHR: 0.13, 95% CI: 0.03-0.46) in HIV acquisition and intervals with seroprotection with a 78% reduction (aHR: 0.22, 95% CI: 0.09-0.57). No CAS is the safest behavior to prevent HIV acquisition. Seroprotective behaviors significantly reduced risk, but HIV incidence was still >2/100 person-years, suggesting that additional strategies, such as pre-exposure prophylaxis, are warranted for this population.
血清适应性被定义为根据自身的艾滋病毒血清学状态、性伴侣的感知艾滋病毒血清学状态以及性行为传播艾滋病毒风险的差异来改变性行为的做法。由于这个定义意味着意图，我们使用“血清保护”一词来描述那些报告仅与血清学阴性伴侣进行无保护肛交（CAS），或者仅作为插入方与艾滋病毒阳性或血清学状态未知的伴侣进行无保护肛交的艾滋病毒阴性参与者。对于男男性行为者（MSM）中的黑人，人们对血清保护知之甚少。我们使用Cox模型评估了参与HPTN 061研究的1144名艾滋病毒阴性黑人男男性行为者中血清保护与艾滋病毒感染之间的独立关联；我们按登记城市进行分层，并控制了性伴侣数量、年龄和药物使用情况。在0、6和12个月时报告的行为被分为三个相互排斥的类别：（1）无无保护肛交；（2）血清保护；（3）无血清保护的无保护肛交。在2861个六个月的时间段内，发生了28例艾滋病毒血清转换。在33.3%的访视中报告无无保护肛交，在46.6%的访视中报告血清保护，在20.1%的访视中报告无血清保护的无保护肛交。无无保护肛交每100人年的血清转换率为0.98（95%置信区间：0.27，2.51），而血清保护和无血清保护的无保护肛交分别为2.39（95%置信区间：1.03，4.71）和13.33（95%置信区间：7.62，21.66）。与无血清保护的无保护肛交相比，无无保护肛交的时间段与艾滋病毒感染减少87%相关（调整后风险比：0.13，95%置信区间：0.03 - 0.46），血清保护的时间段与艾滋病毒感染减少78%相关（调整后风险比：0.22，95%置信区间：0.09 - 0.57）。无无保护肛交是预防艾滋病毒感染最安全的行为。血清保护行为显著降低了风险，但艾滋病毒发病率仍>2/100人年，这表明对于该人群，诸如暴露前预防等额外策略是必要的。
