*Department of Global Community Health and Behavioral Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA; †Department of Community Health, Federal University of Ceará, Fortaleza, Brazil; ‡Department of Epidemiological Surveillance, Ministry of Health, Fortaleza, Fortaleza, Brazil; §Centers for Disease Control and Prevention, Atlanta, Georgia, USA; ‖Oswaldo Cruz Foundation, Rio de Janeiro, Brazil; ¶Director, National Institute of the Fight against AIDS, Luanda, Angola.
J Acquir Immune Defic Syndr. 2014 Aug 15;66(5):544-51. doi: 10.1097/QAI.0000000000000213.
To conduct the first population size estimation and biological and behavioral surveillance survey among men who have sex with men (MSM) in Angola.
Population size estimation with multiplier method and a cross-sectional study using respondent-driven sampling.
Luanda Province, Angola. Study was conducted in a large hospital.
Seven hundred ninety-two self-identified MSM accepted a unique object for population size estimation. Three hundred fifty-one MSM were recruited with respondent-driven sampling for biological and behavioral surveillance survey.
Interviews and testing for HIV and syphilis were conducted on-site. Analysis used Respondent-Driven Sampling Analysis Tool and STATA 11.0. Univariate, bivariate, and multivariate analyses examined factors associated with HIV and unprotected sex. Six imputation strategies were used for missing data for those refusing to test for HIV.
A population size of 6236 MSM was estimated. Twenty-seven of 351 individuals were tested positive. Adjusted HIV prevalence was 3.7% (8.7% crude). With imputation, HIV seroprevalence was estimated between 3.8% [95% confidence interval (CI): 1.6 to 6.5] and 10.5% (95% CI: 5.6 to 15.3). Being older than 25 (odds ratio = 10.8, 95% CI: 3.5 to 32.8) and having suffered episodes of homophobia (odds ratio = 12.7, 95% CI: 3.2 to 49.6) significantly increased the chance of HIV seropositivity.
Risk behaviors are widely reported, but HIV seroprevalence is lower than expected. The difference between crude and adjusted values was mostly due to treatment of missing values in Respondent-Driven Sampling Analysis Tool. Solutions are proposed in this article. Although concerns were raised about feasibility and adverse outcomes for MSM, the study was successfully and rapidly completed with no adverse effects.
在安哥拉男男性行为者（MSM）中进行首次人群规模估计和生物行为监测调查。
使用乘数法进行人群规模估计，并采用横断面研究，使用应答驱动抽样法。
安哥拉罗安达省。该研究在一家大医院进行。
792 名自我认定的 MSM 接受了用于人群规模估计的唯一对象。通过应答驱动抽样法招募了 351 名 MSM 进行生物行为监测调查。
现场进行访谈和 HIV 和梅毒检测。分析使用应答驱动抽样分析工具和 STATA 11.0。单变量、双变量和多变量分析检查了与 HIV 和无保护性行为相关的因素。对于拒绝接受 HIV 检测的人，使用了六种缺失数据插补策略。
估计 MSM 人群规模为 6236 人。351 名个体中，有 27 人检测呈阳性。调整后的 HIV 感染率为 3.7%（粗率为 8.7%）。通过插补，HIV 血清阳性率估计在 3.8%（95%置信区间：1.6 至 6.5）和 10.5%（95%置信区间：5.6 至 15.3）之间。年龄大于 25 岁（比值比=10.8，95%置信区间：3.5 至 32.8）和遭受过同性恋恐惧症发作（比值比=12.7，95%置信区间：3.2 至 49.6）显著增加了 HIV 血清阳性的机会。
广泛报告了风险行为，但 HIV 血清阳性率低于预期。粗率和调整值之间的差异主要是由于在应答驱动抽样分析工具中处理缺失值。本文提出了一些解决方案。尽管对 MSM 的可行性和不良后果表示关注，但该研究仍成功且迅速完成，没有任何不良影响。
