Title: Various Laboratory Techniques for diagnosing Syphilis- A Comparative Study
Authors: Natesan Thilakavathi
Aim: To compare the effectiveness of POCT and VDRL in the screening of syphilis among high risk group (HRG).
Methods and Material: The blood samples were collected from the HRGs' attending the STD OP of IOV from January 2010 to December 2010. The serum specimens from these blood samples were subjected to new point of care test (POCT – Rapid Specific Treponemal) test, Venereal Disease Research Laboratory (VDRL) / Rapid plasma Reagin (RPR) and Treponema pallidum haemagglutination (TPHA).
Statistical analysis used: SPSS version 10.0 and EPI 6 package, Chi-square test. To assess the statistical significance at 5% level, a two-sided test was considered.
Results: A total of 1131 High risk group (HRG) patients attended. Out of this, 599 (59%) were Men who have Sex with Men (MSM), 402 (35.5%) were Female sex worker (FSW), and 130 (15.5%) were Transgender (TG). The positivity rate of Syphilis was 68 among 599 (11.3%) in MSM, 33 among 400 (8.2%) in FSW and 17 among 130 (13%) in TG by POC test. The overall prevalence of syphilis by POCT test was 10.4% in HRG. The positivity rate of syphilis by VDRL test was 3.3(%) The concordance reactivity of the reactive serum sample tested by POC test was 89% with TPHA and was 33% with VDRL. If VDRL alone were used to screen Syphilis, 2/3 of the positive patients would be missed in this group.
Conclusions: The POCT test-screening method is highly sensitive, rapid, cost-effective, and easy to perform. Thus this treponemal test can be used to screen Syphilis to identify the true burden of disease in the community.