Sangthang S, Raturi M, Kandsamy D, Deepika C, Mohan G, Shastry S. Reverse Algorithm Screening of Syphilis and trends in prevalence among Blood Donors in Coastal Karnataka.
Transfus Clin Biol 2022;
29:219-223. [PMID:
35623581 DOI:
10.1016/j.tracli.2022.04.003]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 04/12/2022] [Accepted: 04/12/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND
Transfusion transmissible syphilis is caused by Treponema pallidum; blood donors are traditionally screened with non-treponemal antibody tests to ensure transfusion safety. Detection of specific antibodies against T.pallidum is employed in reverse algorithm screening. We aim to analyze the utility of reverse algorithm screening strategy for T.pallidum and to determine the prevalence trends among blood donors in our centre.
MATERIAL AND METHODS
The study was conducted in a Transfusion Centre catering 2030 bedded Tertiary Care Centre in coastal Karnataka in two timelines from 2012 to 2014, and 2019 to 2020, respectively. A fully automated Enzyme-Linked Immunosorbent Assay and Enhanced Chemiluminescence Immunoassay, which detect both IgM and IgG antibodies against T. pallidum were used in the study. Blood donor's data from 2008 to 2020 were also analyzed to observe the prevalence trends of syphilis among blood donors.
RESULTS
Among 26329 and 388 blood donors screened with ELISA and ECI, 134 (0.51%) and 9 (2.3%) were reactive to T.pallidum antibodies respectively. TPHA confirmed 104 and 9 donors reactive from each of ELISA and ECI reactive donors. The increase in the prevalence of syphilis was observed with the utility of treponemal screening compared to the traditional strategy. The prevalence ranged from 0.02 to 0.28%.
CONCLUSION
The reverse algorithm screening can give a sensitive result compared to the gold standard with 77.61% and 88.9% predictability of true positive for ELISA and ECI. Our study found that the utility of reverse algorithm though mildly increases the discard rate but ensures blood safety to a greater extent.
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