Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA.
Perinatal HIV Research Unit, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.
J Acquir Immune Defic Syndr. 2019 Jun 1;81(2):e39-e48. doi: 10.1097/QAI.0000000000002015.
Measurements of HIV exposure could help identify subpopulations at highest risk of acquisition and improve the design of HIV prevention efficacy trials and public health interventions. The HVTN 915 study evaluated the feasibility of self-administered vaginal swabs for detection of HIV virions to assess exposure.
Fifty 18- to 25-year-old sexually active HIV-seronegative women using contraception were enrolled in Soweto, South Africa. Participants self-administered daily vaginal swabs and answered sexual behavior questions through mobile phone for 90 days. Clinician-administered vaginal swabs, behavioral questionnaires, HIV diagnostic testing, and counseling were performed at 8 clinic visits. Glycogen concentrations assessed adherence to swabbing. Y-chromosome DNA (Yc-DNA) assessed the accuracy of reported condom use. HIV exposure was measured by virion polymerase chain reaction in swabs from 41 women who reported unprotected vaginal sex during follow-up.
Glycogen was detected in 315/336 (93.8%) participant-collected and in all clinician-collected swabs. Approximately 20/39 daily swabs (51.3%) linked to mobile reports of unprotected sex tested positive for Yc-DNA, whereas 10/187 swabs collected after 3 days of abstinence or protected sex (5.3%) had detectable Yc-DNA. No participant became HIV infected during the study; yet, exposure to HIV was detected by nucleic acids in 2 vaginal swabs from 1 participant, collected less than 1 hour after coitus.
There was high adherence to daily vaginal swabbing. Daily mobile surveys had accurate reporting of unprotected sex. Detection of HIV in self-collected vaginal swabs from an uninfected participant demonstrated it was possible to measure HIV exposure, but the detection rate was lower than expected.
HIV 暴露的测量可以帮助确定感染风险最高的亚群，并改进 HIV 预防效果试验和公共卫生干预措施的设计。HVTN 915 研究评估了自我采集阴道拭子以检测 HIV 病毒颗粒来评估暴露的可行性。
50 名年龄在 18 至 25 岁之间、正在使用避孕措施的性活跃的 HIV 血清阴性妇女在南非的索韦托被招募。参与者通过手机自行每天采集阴道拭子并回答性行为问题，共 90 天。在 8 次就诊时进行临床医生采集的阴道拭子、行为问卷、HIV 诊断检测和咨询。通过对 41 名在随访期间报告无保护阴道性行为的女性的阴道拭子进行病毒聚合酶链反应（PCR）测量 HIV 暴露情况。
在 336 个参与者采集的拭子中，315 个（93.8%）和所有临床医生采集的拭子中都检测到了糖原。大约 20/39 个与未报告的性行为相关的每日拭子（51.3%）通过 Y 染色体 DNA（Yc-DNA）检测呈阳性，而 10/187 个在禁欲或保护性行为后 3 天采集的拭子（5.3%）有可检测到的 Yc-DNA。在研究期间，没有参与者感染 HIV；然而，在一名参与者的 2 个阴道拭子中通过核酸检测到了 HIV 暴露，这两个拭子是在性行为后不到 1 小时采集的。
每天进行阴道拭子采集的依从性很高。每日的移动调查准确报告了无保护的性行为。从一名未感染的参与者中采集的自我采集的阴道拭子中检测到 HIV 表明有可能测量 HIV 暴露，但检测率低于预期。
