Routine, Opt-Out, Emergency Department Syphilis Testing Increases HIV Preexposure Prophylaxis Uptake

Background: Many people vulnerable to HIV do not perceive themselves at risk or consider preexposure prophylaxis (PrEP). This study hypothesizes that syphilis diagnosis through universal, emergency department (ED) screening would increase PrEP uptake. Methods: This prospective cohort study enrolled patients tested for syphilis through ED screening between July 2019 and July 2021. Participants completed a survey about behaviors, HIVand PrEP knowledge, and opinions at the time of enrollment. All were offered PrEP if they met Centers for Disease Control and Prevention guidelines for PrEP use. Information about PrEP use and HIV status was collected 6 months later. Bivariate analysis was used to compare outcomes between groups testing positive versus negative for syphilis. Results: The study enrolled 97 participants, 49 with syphilis and 48 testing negative. Overall, 11 (11.3%) started PrEP, all in the syphilis group, despite 28 (58.3%) in the negative group having indications for PrEP. Participants with syphilis less frequently reported low perceived HIV risk than syphilis-negative participants who reported HIV transmission behaviors (83.7% vs. 92.9%). Participants reporting moderate to high HIV risk perception were significantly more likely to start PrEP (odds ratio, 10.5; 95% confidence interval, 1.41-78.1; P = 0.02). At 6 months, 3 participants remained on PrEP (follow-up data available for 63.5% of PrEP-eligible participants). Conclusions: Syphilis diagnosis was associated with increased perception of HIV risk and increased PrEP initiation. Individuals who otherwise might not seek testing for syphilis because of perceived low risk may be identified through routine screening, thus providing an important opportunity to link more people to HIV prevention and PrEP services.