Background
Doxycycline post-exposure prophylaxis (doxy-PEP) offers a cheap and effective method for pharmacologic syphilis and chlamydia prevention among men who have sex with men but is underutilized by populations most in need. While syphilis can be easily treated and prevented, young Black sexually minoritized men (YBSMM) in the United States continue to bear the brunt of new infections. This study examined factors associated with syphilis acquisition and doxy-PEP interest among an HIV status-neutral cohort of YBSMM.
Methods
The N2 (Networks and Neighborhoods) Phase 2 cohort included YBSMM aged 16-34 years, identifying as Black, assigned male at birth, who reported at least 1 sexual encounter with a cisgender man or transgender woman in the past 12 months. Our primary outcome was defined as active syphilis with a titer of 1:8 or greater. Generalized linear models were fit to calculate the unadjusted and adjusted relative risks between participants with and without active syphilis based on demographics, health factors, substance use, and doxy-PEP interest.
Results
468 participants were included in the analysis and 25.6% had active syphilis. Participants with active syphilis were older (28.7 years, SD 3.6 vs. 27.6 years, SD 3.8, p<0.01) and had an increased HIV prevalence (81.7% vs. 46.0%, p<0.01). A higher proportion of those with active syphilis were interested in doxy-PEP to prevent syphilis (75.5% vs. 54.7%, p<0.01) and reported methamphetamine use in the past year (26.7% vs. 8.9%, p<0.01) compared to those without active syphilis. In the adjusted models, the risk of having active syphilis among those living with HIV was 2.88 times higher (95% CI: 1.83, 4.53, p<0.01), and methamphetamine use was associated with a 95% increased risk of active syphilis among YBSMM (RR 1.95, 95% CI: 1.43, 2.66, p<0.01) compared to those who did not report methamphetamine use. Interest in doxy-PEP was also positively associated with active syphilis (RR 1.55, 95% CI 1.04, 2.32, p=0.03).
Conclusions
YBSMM who are living with HIV and/or syphilis, and those that use methamphetamine and are interested in utilization of doxy-PEP represent an important demographic for scale-up of doxy-PEP. Given the relative cost of treating syphilis and other STIs to the prevention of syphilis, it would be prudent for public health departments across the United States to share in the prioritization of syphilis prevention among YBSMM, especially those who are interested in it.