Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA.
Sex Transm Infect. 2019 Aug;95(5):336-341. doi: 10.1136/sextrans-2018-053865. Epub 2019 Apr 22.
While men who have sex with men (MSM) are disproportionately affected by Peru's overlapping HIV and STI epidemics, there are few data on how partnership-level and network-level factors affect STI transmission in Peru. We explored partnership-level and network-level factors associated with gonorrhoea/chlamydia ( and/or (NG/CT)) and/or syphilis infection among MSM in Peru.
We present the results of a cross-sectional secondary analysis of MSM (n=898) tested for syphilis and NG/CT infection as part of the screening process for two STI control trials in Lima, Peru. Participants completed questionnaires on demographics, sexual identity and role, characteristics of their three most recent sexual partners (partner sexual orientation, gender, role, partnership type, partner-specific sexual acts) and 30-day sexual network characteristics (number of sexual partners, partnership types, frequency of anal/vaginal intercourse). Participants were tested for syphilis and urethral, rectal and oropharyngeal NG/CT. Differences in network characteristics were analysed with χ and Kruskal-Wallis tests.
Approximately 38.9% of participants had a new STI diagnosis (syphilis (rapid plasma reagin ≥16): 10.6%; NG/CT: 22.9%; syphilis-NG/CT coinfection: 5.4%). Condomless anal intercourse (CAI) was not significantly associated with an STI diagnosis. Gay-identified participants with exclusively homosexual networks had a higher prevalence of STIs (47.4%) than gay-identified MSM with only heterosexual/bisexual partners (34.6%, p=0.04), despite reporting fewer sexual partners (any partners: 2, 1-4 vs 3, 2-6; p=0.001; casual partners: 1, 0-3 vs 2, 1-4; p=0.001) and more stable partnerships (1, 0-1 vs 0, 0-1; p=0.003) in the last month.
Network size and the number of casual sexual partners were associated with NG/CT infection among MSM in Peru. Despite reporting fewer sexual risk behaviours (smaller network size, more stable partnerships, less CAI), MSM with homosexual-only sexual networks had a higher prevalence of NG/CT and syphilis. These findings suggest network composition among MSM in Peru plays an important role in the risk for STI acquisition.
男男性行为者（MSM）受到秘鲁 HIV 和性传播感染（STI）双重流行的不成比例影响，但关于伙伴关系层面和网络层面因素如何影响秘鲁 STI 传播的数据很少。我们探讨了与秘鲁 MSM 中淋病/衣原体（NG/CT）和/或梅毒感染相关的伙伴关系层面和网络层面因素。
我们报告了在秘鲁利马进行的两项性传播感染控制试验的筛查过程中，对 898 名接受梅毒和 NG/CT 感染检测的 MSM 进行横断面二次分析的结果。参与者完成了关于人口统计学、性身份和角色、他们最近三次性伴侣特征（伴侣的性取向、性别、角色、伴侣类型、伴侣特定性行为）和 30 天性网络特征（性伴侣数量、伴侣类型、肛门/阴道性交频率）的调查问卷。参与者接受了梅毒和尿道、直肠和口咽 NG/CT 检测。使用 χ 和 Kruskal-Wallis 检验分析网络特征差异。
约 38.9%的参与者有新的 STI 诊断（梅毒（快速血浆反应素≥16）：10.6%；NG/CT：22.9%；梅毒-NG/CT 合并感染：5.4%）。无保护肛交（CAI）与 STI 诊断无显著关联。同性恋身份且仅具有同性恋网络的 MSM 比同性恋身份且仅有异性恋/双性恋伴侣的 MSM 有更高的 STI 患病率（47.4%比 34.6%，p=0.04），尽管报告的性伴侣较少（任何伴侣：2，1-4 比 3，2-6；p=0.001；偶然伴侣：1，0-3 比 2，1-4；p=0.001），且最近一个月的稳定伴侣关系更多（1，0-1 比 0，0-1；p=0.003）。
网络规模和偶然性行为伴侣数量与秘鲁 MSM 中的 NG/CT 感染相关。尽管报告的性行为风险行为较少（网络规模较小，伴侣关系更稳定，CAI 较少），但仅具有同性恋网络的 MSM 中 NG/CT 和梅毒的患病率更高。这些发现表明，秘鲁 MSM 的网络构成在 STI 获得风险中起着重要作用。
