Background: Expedited partner therapy (EPT) is an intervention for patients with gonorrhea (NG) or chlamydia (CT), providing index patients with prescriptions or medication to give to their partners. EPT is recommended for heterosexuals but not for men who have sex with men (MSM), partially due to concerns about overtreatment of uninfected partners and missed opportunities for HIV diagnosis.
Methods: We extended our stochastic network-based mathematical model of HIV, NG, and CT among MSM to include EPT. EPT implementation was simulated for 10 years. Counterfactual scenarios varied EPT coverage, provision, uptake, and partnership window duration. We estimated sexually transmitted infection (STI) incidence, the proportion of infections averted (PIA), and process outcomes under each scenario.
Results: Delivery of EPT to 20% of eligible MSM index patients (coverage) reduced cumulative STI incidence by 27% (interquartile range (IQR): 13%-39%) over 10 years compared to current estimated STI screening levels. A 20% increase in providing medication to non-index partners (provision) averted 32% (IQR: 20%-41%) of STI infections compared to estimated STI screening levels. When targeted by partnership type, EPT solely to casual partners maximized the population infections averted. The proportion of partners given medication who had no current STI varied from 52% to 63%, depending on coverage level. The proportion of partners given medication with undiagnosed HIV infection was 4% across scenarios.
Conclusions: EPT could reduce bacterial STI incidence for MSM. However, this intervention could result in missed opportunities for HIV/STI prevention and a substantial increase in use of antimicrobials by STI-uninfected MSM, raising concerns about cost and antimicrobial resistance.