This work was presented at the August 2018 National STD Prevention Conference in Washington, DC.
Incidence of bacterial sexually transmitted infections (STIs) in men who have sex with men (MSM) remains substantial despite widespread availability of effective antibiotics. The US Centers for Disease Control and Prevention (CDC) recommends at least annual screening for all sexually active MSM and more frequent screening for higher-risk MSM, but it is unknown whether increased coverage or frequency of screening could lower STI incidence. We used mathematical modeling to estimate the reduction in sexually transmitted infection (STI) incidence associated with varying coverage and frequency of STI screening in men who have sex with men (MSM).
We simulated 10 years of STI screening among MSM, based on the CDC guidelines, using a network-based transmission model of HIV, gonorrhea (NG), and chlamydia (CT). We assumed current empirical screening levels from National HIV Behavioral Surveillance (NHBS). Counterfactual scenarios evaluated increased screening coverage and frequency for sexually active MSM and higher-risk MSM with multiple recent sexual partners, estimating the percent of infections averted and the number needed to screen to prevent one new infection.
Semiannual screening of sexually active MSM at current NHBS levels, with 5% coverage of HR screening, could avert an estimated 71% of NG and 78% of CT infections expected over 10 years. Semiannual screening of 30% of higher-risk MSM, on top of current coverage levels of annual SA screening, could avert 76% of NG and 84% of CT infections.
Downloadable Files:STD Conference 2018_Weiss.pptx
Targeted screening of higher-risk MSM based on a behavioral indication such as recent sexual activity can improve the population-level impact of routine STI screening. Frequent screening of sexually active and higher-risk MSM could lead to near-elimination of STIs.