High burden of active syphilis and HIV/syphilis co-infection among men who have sex with men, transwomen, and genderqueer individuals in Zimbabwe.

Background Syphilis increases HIV acquisition risk and impacts the immunologic and virologic response among people living with HIV (PLHIV). We assessed the prevalence of active or current syphilis and HIV/syphilis and their correlates among men who have sex with men (MSM), transwomen, and genderqueer (TGW/GQ) individuals in Zimbabwe. Methods Among a respondent-driven sample of MSM and TGW/GQ who were tested for HIV and syphilis in Harare and Bulawayo, Zimbabwe in 2019 (n = 1511), multiple logistic regression was used to assess correlates of active syphilis. Unadjusted logistic regression was used among PLHIV (n = 340) due to small sample size. All analyses were unweighted as data did not reach convergence for HIV. Results Prevalence of active syphilis overall and among PLHIV was 5.5% and 10.1%, respectively, in Harare, and 5.6% and 11.0%, respectively, in Bulawayo. Participants were more likely to have active syphilis if they were PLHIV (aOR:2.2, 95%CI:1.4-3.6), aged 25-34 (aOR:2.2, 95%CI:1.3-3.8, ref:18-24), or self-report STI symptoms (aOR:1.8, 95%CI:1.1-3.0). Compared to Bulawayo TGW/GQ, MSM in Harare (aOR:0.2, 95%CI:0.1-0.5) and Bulawayo (aOR:0.2, 95%CI:0.1-0.4), and TGW/GQ in Harare (aOR:0.2, 95%CI:0.1-0.6) were less likely to have active syphilis. Among PLHIV, co-infection was 13.0% among TGW/GQ and 9.7% among MSM. Odds of co-infection were higher for those aged 25-34 (OR:3.7, 95%CI:1.2-11.1) and lower among Harare MSM (OR:0.2, 95%CI:0.1-0.7), Bulawayo MSM (OR:0.1, 95%CI:0.0-0.4), and Harare TGW/GQ (OR:0.1, 95%CI:0.0-0.4) compared to Bulawayo TGW/GQ. Conclusions Findings highlight a high burden of syphilis among MSM and TGW/GQ and underscore the importance of HIV/syphilis detection and improved service delivery for these groups.