Background
Syndromic management of STIs often limits their detection and targeted treatment. MSW typically display low health-seeking behavior and this,
paired with exposure to asymptomatic STIs from partners, exacerbates risks of transmission. MSM, perceiving marginalization within health services, typically limit STI symptom-reporting essential for initiation of treatment algorithms. Diagnostic STI testing and management are therefore critical to an effective STI prevention response, which in turn is essential for preventing HIV/STI acquisition and re-infection.
Methods
We conducted a 12-month, randomized crossover study (July 2022-June 2024) where MSW and MSM in Cape Town and Johannesburg, South Africa
were administered three bimonthly gluteal placebo injections and at crossover, a six-month placebo subdermal implant each, as proxies for long-acting PrEP delivery modalities. At screening, Months 6, 12, and when indicated, clinical assessments included collection of urine and blood samples for HIV (Ag/Ab rapids); syphilis (RPR/TPHA); Chlamydia trachomatis (CT) and Neisseria gonorrhea (GC) testing (GeneXpert). Men testing HIV-positive were referred for ART services and those with GC/CT/syphilis were treated on-site. Partner notification cards for accessing treatment were offered.
Results
We screened 251 potential participants, of whom 184 were enrolled (median age 22, IQR 22-27). Men had a median of three sex partners in the past
six months (IQR 2-5). Baseline testing identified 22 prevalent HIV infections (8.8%), 24 syphilis, 33 CT and 4 GC infections (22.7% prevalence of bacterial STIs [26.9%MSM, 17.9%MSW]). Over 12-months of follow-up, diagnostic testing detected a further six incident HIV infections among MSM, 26 syphilis infections in 15 men (12 MSM, 3 MSW); 24 CT infections in 19 men (6 MSM, 13 MSW), and 9 GC infections among 8 men (2 MSM, 6 MSW). Forty-one enrolled participants experienced at least one lab-diagnosed bacterial STI (22.2% incidence).
Conclusions
We found high incidence of HIV and bacterial STIs among both groups of men, with higher incidence of HIV and syphilis among MSM and CT/GC
among MSW. Coinfection and recurring infections, combined with STIs preceding HIV acquisition, reinforce urgency around identifying a more effective STI
response for men in South Africa. Innovative diagnostic and treatment strategies including use of testing paired with expedited partner therapy need further
exploration.