ABSTRACT
BACKGROUND: Herpes simplex virus (HSV) has been the leading cause of genital ulcer syndrome (GUS) in South Africa for more than a decade, and acyclovir therapy is incorporated into syndromic management guidelines. We conducted surveillance at 3 sentinel sites to define the common sexually transmitted etiologies of GUS and to determine whether current syndromic management is appropriate. Secondary objectives of surveillance were to determine the seroprevalence of coinfections (HIV, syphilis, HSV-2) in persons presenting with GUS. METHODS: Consecutive, consenting adult men and women presenting with visible genital ulceration were enrolled between January 1, 2019, and December 31, 2020. Genital ulcer swab and blood specimens were collected and transported to a central sexually transmitted infection reference laboratory in Johannesburg. RESULTS: Among 190 participants with GUS, HSV-2 was the most frequently detected ulcer pathogen (49.0%; 95% confidence interval [CI], 41.9%-56.1%). The relative prevalence of the second most common ulcer-derived pathogen, Treponema pallidum, was 26.3% (95% CI, 20.5%-33.1%), with 90% of primary syphilis cases having a positive rapid plasma reagin (RPR) titer. Male sex was independently associated with primary syphilis compared with herpetic ulcers, after adjusting for the effect of casual sex partners and other exposures (adjusted odds ratio, 3.53; 95% CI, 1.35-9.21; P = 0.010). The overall HIV prevalence among participants was 41.3% (78 of 189; 95% CI, 34.2%-48.6%). CONCLUSIONS: Herpes simplex virus 2 remains the predominant cause of GUS, justifying the continued use of acyclovir in syndromic guidelines. Adequate supplies of benzathine penicillin G for syphilis treatment are essential at primary health care level, in addition to the provision of syphilis and HIV risk reduction services.