HIV and Syphilis Testing Among Patients Tested for Gonorrhea and Chlamydia in Emergency Departments

Abstract

Introduction Sexually transmitted infections (STIs), including HIV and syphilis, are increasing. In 2023, there were over 2.4 million reported cases of chlamydia, gonorrhea, and syphilis in the United States, a 32.5% increase from 2014. Emergency departments (EDs) are vital touchpoints for STI testing, yet HIV and syphilis testing among patients undergoing Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) testing is suboptimal. We aimed to determine testing frequency and to identify factors associated with HIV and syphilis co-testing among ED patients undergoing NG/CT testing. Methods We conducted a retrospective observational study of all patients tested for NG/CT from 2021–2024 at two Los Angeles EDs. Covariates including sociodemographic and behavioral data were extracted from the medical record. The primary outcome was complete STI testing, defined as both HIV and syphilis testing during or up to six months prior to an ED encounter with NG/CT testing. Multivariable logistic regression was used to evaluate factors associated with complete STI testing. Results Of 3,940 patients, 459 (11.7%) received complete STI testing. Among patients receiving complete STI testing, 176 (38.3%) were female, 282 (61.4%) were male, 96 (20.9%) were Hispanic, 98 (21.4%) were non-Hispanic Black, 195 (42.5%) were non-Hispanic White, 220 (47.9%) had Medicare insurance, 132 (28.8%) had private insurance, 225 (49.0%) were experiencing homelessness, 14 (3.1%) identified as bisexual, and 90 (19.6%) identified as heterosexual. In multivariable analysis, patients who were bisexual (adjusted odds ratio [aOR] 2.51; 95% CI, 1.32–4.80; P = .005); had Medicare insurance (aOR 1.89; 1.20–2.98; P = .006); or were experiencing homelessness (aOR 5.21; 4.00–6.78; P < .001) had higher odds of complete STI testing. Patients who were Hispanic (aOR 0.69; 0.52–0.92; P = .01); non-Hispanic Black (aOR 0.75; 0.56–1.00, P = .05); or female (aOR 0.68; 0.54–0.85; P = .001) had lower odds. Of 261 patients with multiple ED encounters, 217 (83.1%) never received complete testing. Conclusion Complete HIV and syphilis testing among ED patients tested for N. gonorrhoeae and C. trachomatis was low, even among patients with multiple ED encounters. Lower testing among Hispanic and non-Hispanic Black patients may exacerbate existing disparities in STIs. Implementation research is needed to improve the integration of STI testing in EDs.