Introduction of rapid tests for large-scale syphilis screening among female, male, and transgender sex workers in Mumbai, India.

BACKGROUND: Despite widespread availability of rapid plasma reagin (RPR) for syphilis screening at sex worker (SW)-dedicated project clinics, uptake of syphilis testing remains low and prevalence of syphilis remains high among SWs in Maharashtra, India. The primary reasons given for refusal of RPR were fear of venipuncture and long waiting times for results.
METHODS: Between December 2007 and February 2008, rapid point of contact diagnostic tests (Syphicheck-WB, Qualpro Diagnostics, India) using finger-prick samples were introduced for syphilis screening, with RPR confirmation test of positives.
RESULTS: Uptake of syphilis screening among clinic attenders increased to 63.1% compared with an average of 14.3% before the intervention. Among the 19,809 SWs who were screened, 598 tested positive (3% prevalence of lifetime infection). Of these, 395 (66.1%) accepted RPR confirmation test; 337 (88.3%) were seroreactive, 160 (40.5%) had titers ≥1:8 (active syphilis). The projected overall prevalence of active syphilis among all SWs screened was 1.2% but varied by site and typology of sex work (brothel-based, 2.4%; bar-based, 0.5%; street-based, 2.3%; male SWs, 0.2%; transgender, 11.3%; home-based, 0.6%).
CONCLUSIONS: The introduction of rapid tests dramatically increased the uptake of syphilis screening in this large-scale intervention among a high-risk population in India. However, only two-thirds of SWs with a positive rapid test accepted a confirmatory RPR test. The high proportion (40.5%) of active syphilis among those testing positive on the rapid screening test justifies treatment even if confirmatory testing is declined. A commercially available, simple, rapid nontreponemal test is needed to further strengthen syphilis screening.