Sexually Transmitted Infection (STI) Incidence and Risk Factors Among People with HIV (PWH): Insights from a 13-Year Cohort Study in South Carolina

The Ending the HIV Epidemic (EHE) initiative aims to reduce new HIV infections by 90% by 2030 in the United States (US). However, rising sexually transmitted infection (STI) rates exacerbate the bidirectional infection risk between HIV and STIs. Most research on STIs among people with HIV (PWH) has focused on high-risk groups, resulting in limited data on broader populations. This study addresses that gap by examining the incidence and risk factors for gonorrhea, chlamydia, and syphilis in a statewide cohort of PWH in South Carolina. Data from South Carolina's HIV and STI surveillance systems were linked, and all PWH aged 18 and older who were diagnosed with HIV between 2007 to April 2018 were included. Cohort demographics were analyzed using descriptive statistics and chi-squared tests, and a Cox Proportional Hazards model examined time to first STI after HIV diagnosis. The study found an increase in the incidence of gonorrhea, chlamydia, and syphilis over the study period. Young adults, men, Black individuals, MSM, and urban residents were found to be at increased risk for STI diagnosis. Clinical risk factors associated with increased STI risk included lower initial CD4 counts, and higher initial viral loads. The findings underscore a considerable STI burden among PWH in South Carolina. To mitigate STI transmission in the context of HIV, targeted interventions for high-risk populations are needed.