Syphilis Serology among HIV-Seroreactive Patients

Sexually transmitted diseases (STD’s), including Syphilis, are associated with an increased risk of Human immunodeficiency virus (HIV) infection. Though Rapid Plasma Reagin test (RPR) is a screening test to diagnose syphilis, a negative RPR may not rule out syphilis in HIV sero-reactive patients. For laboratory confirmation, one specific treponemal test, namely Treponema Pallidum Haemagglutination Assay (TPHA) or Fluorescent Treponemal Antibody Absorption test (FTA-ABS) should be done along with RPR. The aim of present study was to diagnose syphilis among HIV-reactive Integrated counseling and testing centre (ICTC) attendees visiting Government Hospital, Khammam using both RPR and TPHA. The present study was conducted at Dept. Of Microbiology, Mamata Medical College, Khammam. Blood was collected from 200 HIV-reactive ICTC attendees over a period of 10 months (January to October 2013). Sera were separated and stored at -200c. All the sera were screened for syphilis by RPR and also with TPHA immunochromatographic cassette test. Out of 200 HIV positive cases, 56 (28%) were reactive to RPR and 18 (9%) were positive to TPHA. Among 18 TPHA positive sera only 14 were reactive to RPR. 42 out of 56 RPR reactive sera were biological false positives (BFPs). Seroprevalance of syphilis was higher in the age group of 30-40yrs and in females. 15 among 18 syphilis positive cases had a CD4 count below 250 cells/ mm. The specificity of non-treponemal serological test may be compromised in a HIV-infected with biological false positives. Both treponemal and nontreponemal tests for syphilis are accurate in the majority of patients with syphilis and HIV co-infection.