Population Health Sciences, University of Bristol, Bristol, UK
Sigma Research, Faculty of Public Health & Policy, London School of Hygiene and Tropical Medicine, London, UK.
Sex Transm Infect. 2021 Jun;97(4):282-289. doi: 10.1136/sextrans-2020-054629. Epub 2021 Jan 15.
In the last decade diagnoses of most STIs have risen among men who have sex with men (MSM). Although a significant proportion of this is likely due to increased STI screening, understanding the role of behavioural drivers remains critical. We measure the associations between stimulant use to enhance and prolong sexual experiences (chemsex) and bacterial STI diagnoses in UK MSM, individually considering HIV-diagnosed MSM, pre-exposure prophylaxis (PrEP) users and other MSM.
We used the UK 2017-2018 European MSM Internet Survey data (n=9375). We constructed causal inference models using multivariable logistic regression, calculating adjusted OR (aOR) and 95% CI of the associations between participation in recent (≤12 months) exclusively dyadic or multipartner chemsex versus no chemsex and recent self-reported diagnoses of syphilis, gonorrhoea and chlamydia.
Among MSM with an HIV diagnosis, 25% of users indicated recent multipartner chemsex, vs 28% of PrEP users and 5% of other MSM. Adjusting for age, ethnicity, UK birth, cis-trans status, sexual identity, education, settlement size and relationship status, participation in recent multipartner chemsex versus no chemsex was associated with greater odds of recent syphilis, gonorrhoea and chlamydia diagnosis. aORs for recent syphilis, gonorrhoea and chlamydia diagnoses were 2.6 (95% CI 1.7 to 4.1), 3.9 (95% CI 2.6 to 5.8) and 2.9 (95% CI 1.9 to 4.3), respectively, in HIV-diagnosed MSM; 1.9 (95% CI 1.1 to 3.3), 2.9 (95% CI 2.0 to 4.2) and 1.9 (95% CI 1.3 to 2.8), respectively, in PrEP users; and 4.0 (95% CI 2.3 to 6.9), 2.7 (95% CI 1.9 to 3.8) and 2.3 (95% CI 1.6 to 3.4), respectively, in other MSM. Conversely, exclusively dyadic chemsex had no significant associations with bacterial STI diagnoses among HIV-diagnosed MSM, only gonorrhoea (aOR 2.4, 95% CI 1.2 to 4.7) among PrEP users and syphilis (aOR 2.8, 95% CI 1.4 to 5.6) among other MSM.
Multipartner chemsex may drive the association between chemsex and bacterial STI diagnoses and thus should be the focus of future tailored chemsex interventions. Additionally, PrEP acceptability among MSM and particularly chemsex participants has generated an emergent group suitable for such interventions.
在过去的十年中，男男性行为者（MSM）中的大多数性传播感染（STI）诊断有所增加。尽管其中很大一部分可能是由于 STI 筛查的增加，但了解行为驱动因素仍然至关重要。我们衡量了在英国 MSM 中，为了增强和延长性体验而使用兴奋剂（化学性行为）与细菌性 STI 诊断之间的关联，分别考虑了 HIV 确诊 MSM、暴露前预防（PrEP）使用者和其他 MSM。
我们使用了英国 2017-2018 年欧洲 MSM 互联网调查数据（n=9375）。我们使用多变量逻辑回归构建了因果推理模型，计算了最近（≤12 个月）仅限二元或多伙伴化学性行为与无化学性行为与最近自我报告的梅毒、淋病和衣原体感染之间的关联的调整优势比（aOR）和 95%置信区间。
在 HIV 确诊的 MSM 中，25%的使用者表示最近进行了多伙伴化学性行为，而 PrEP 使用者为 28%，其他 MSM 为 5%。调整年龄、种族、英国出生、顺式-反式状态、性身份、教育、居住规模和关系状况后，与最近多伙伴化学性行为相比，无化学性行为与最近梅毒、淋病和衣原体感染的诊断几率更高。HIV 确诊 MSM 中，最近梅毒、淋病和衣原体感染的 aOR 分别为 2.6（95%CI 1.7 至 4.1）、3.9（95%CI 2.6 至 5.8）和 2.9（95%CI 1.9 至 4.3）；PrEP 使用者中，分别为 1.9（95%CI 1.1 至 3.3）、2.9（95%CI 2.0 至 4.2）和 1.9（95%CI 1.3 至 2.8）；其他 MSM 中，分别为 4.0（95%CI 2.3 至 6.9）、2.7（95%CI 1.9 至 3.8）和 2.3（95%CI 1.6 至 3.4）。相反，在 HIV 确诊 MSM 中，仅限二元的化学性行为与细菌性 STI 诊断之间没有显著关联，仅在 PrEP 使用者中与淋病（aOR 2.4，95%CI 1.2 至 4.7）和其他 MSM 中与梅毒（aOR 2.8，95%CI 1.4 至 5.6）有关。
多伙伴化学性行为可能是化学性行为与细菌性 STI 诊断之间关联的驱动因素，因此应成为未来针对化学性行为的干预措施的重点。此外，PrEP 在 MSM 中的可接受性，尤其是在化学性行为参与者中的可接受性，已经产生了一个适合此类干预措施的新兴群体。
