South Africa has a large burden of bacterial sexually transmitted infections (STIs) with high rates among men who have sex with men (MSM). Randomised controlled trials have recently demonstrated high effectiveness of doxycycline post-exposure prophylaxis (PEP) for prevention of bacterial STIs in MSM, with 70% - 85% reductions in Chlamydia trachomatis infection and syphilis, and approximately 50% reduction in Neisseria gonorrhoeae infection. Doxycycline PEP was not demonstrated to be effective in reducing C. trachomatis and N. gonorrhoeae infection among Kenyan cisgender women. Although no worrisome trends in antimicrobial resistance (AMR) were observed in the trials, important concerns remain about doxycycline PEP and AMR development in STIs, other pathogens, commensals, and the microbiome. Tetracycline resistance in N. gonorrhoeae is already widespread in South Africa, but emergence of AMR in other STIs would be concerning. Larger sample sizes of doxycycline PEP users with longer follow-up time are needed to understand the impact that doxycycline PEP may have on AMR at individual and population level. In this opinion article, we weigh the benefits of doxycycline PEP for prevention of bacterial STIs against the existing AMR concerns and data gaps in the South African context. Based on the current evidence, we conclude that it would be reasonable to offer doxycycline PEP to high-risk MSM on a case-by-case basis, provided that it is offered by experienced sexual health clinicians in settings that have access to diagnostic STI testing and ongoing AMR surveillance.

中文翻译：

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南非使用多西环素治疗性传播感染的暴露后预防。

南非的细菌性传播感染 (STI) 负担很重，男男性行为者 (MSM) 的感染率很高。最近的随机对照试验表明，强力霉素暴露后预防 (PEP) 对于预防 MSM 中的细菌性 STI 非常有效，沙眼衣原体感染和梅毒可减少 70% - 85%，淋病奈瑟菌感染可减少约 50%。多西环素 PEP 并未被证明能有效减少肯尼亚顺性别女性中的沙眼衣原体和淋病奈瑟菌感染。尽管在试验中没有观察到令人担忧的抗菌素耐药性 (AMR) 趋势，但对于性传播感染、其他病原体、共生菌和微生物组中多西环素 PEP 和 AMR 的发展仍然存在重要担忧。淋病奈瑟菌对四环素的耐药性在南非已经很普遍，但其他性传播感染中出现的抗菌素耐药性则令人担忧。需要更大的多西环素 PEP 用户样本量和更长的随访时间，才能了解多西环素 PEP 对个人和人群水平的 AMR 可能产生的影响。在这篇评论文章中，我们权衡了强力霉素 PEP 在预防细菌性性传播感染方面的益处以及南非现有的抗菌素耐药性问题和数据差距。根据目前的证据，我们得出的结论是，根据具体情况向高危 MSM 提供多西环素 PEP 是合理的，前提是由经验丰富的性健康临床医生在能够进行 STI 诊断检测的环境中提供。以及持续的抗菌素耐药性监测。