Trends in syphilis seroreactivity among blood donors: A 17-year retrospective analysis and follow-up at a tertiary care hospital.

Abstract

Background and objectives: This study aimed to assess the seroprevalence of syphilis among blood donors, evaluate the response rate of seroreactive donors, and investigate high-risk behaviors.

Material and methods: The study presents a retrospective analysis of syphilis seroreactivity among blood donors over a 17 year period. Blood donations were screened for syphilis using the Rapid Plasma Reagin (RPR) card test. RPR-reactive blood units were discarded, and donors were notified for follow-up. A detailed history was obtained, including prior syphilis diagnoses, sexual practices, and potential high-risk activities. The donors who were repeatedly RPR reactive were referred for further confirmatory management.

Results: A total of 569 (0.20 %) donors were found RPR reactive. A non-linear trend was observed between RPR reactivity and study period, donor age and donation status. RPR reactivity was significantly higher in repeat blood donors (p < 0.001). The mean donor return rate was significantly higher following introduction of phone calls along with letters for donor notification compared to notification via letters only (p < 0.001). Forty-five percent (n = 241) donors returned for repeat sample testing. Of these, 19 % (n = 45) tested negative on repeat RPR testing while 81.3 % (n = 196) remained RPR reactive and were referred for further management. On follow up of the latter group, 43.9 % (n = 86) donors were negative on confirmatory testing indicating biological false positives while 56.1 % (n = 110) donors were positive on confirmatory testing and were true positives. Of true positive donors, 90.9 % of donors reported engaging in high risk sexual behaviours.

Conclusion: There is a need to update syphilis screening guidelines in developing countries like India, incorporating combination testing to improve the accuracy of syphilis detection in blood donors.