Open Forum Infectious Diseases | October 2019
Purpose: Incidence of bacterial sexually transmitted infections (STIs) in men who have sex with men (MSM) remains substantial despite the 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.
Methods: We extended our network-based transmission model of HIV, gonorrhea (NG), chlamydia (CT), and syphilis among MSM to simulate 10 years of STI screening based on the CDC guidelines. The base case assumed annual screening across MSM at current empirical levels; counterfactual scenarios evaluated increased screening coverage and frequency in all sexually active MSM and MSM with multiple sexual partners in the past six months. Percent of infections averted and the number needed to test to prevent one new infection were estimated.
Results: Biannual testing of sexually active MSM at empirical coverage levels, with little higher-risk screening, could avert an estimated 63% of NG/CT and 44% of syphilis infections expected over the next decade. Biannual testing of 30% of higher-risk MSM, holding annual screening levels fixed, with multiple recent sexual partners could avert 71% of NG/CT and 39% of syphilis infections.
Conclusions: Focused screening of higher-risk MSM based on simple behavioral indications can improve the population-level impact of routine STI screening, although optimal screening approaches may differ by STI. Frequent screening of all MSM along with a focused screening of higher-risk MSM could reduce STI prevalence in this high-burden subpopulation.
Downloadable Files:STD Conference 2018_Weiss_0.pptx