Using a dual antibody point-of-care test with visual and digital reads to diagnose syphilis among people living with HIV in Botswana

Int J STD AIDS. 2021 Apr;32(5):453-461. doi: 10.1177/0956462420975639. Epub 2021 Feb 11.

Abstract

Syphilis data from low- and middle-income countries are lacking due to limited testing. Point-of-care tests (POCTs) have been promoted to expand testing but previously only included treponemal tests, which cannot distinguish active from past infection. We aimed to assess the feasibility of using a combined treponemal and non-treponemal POCT in HIV clinic patients in Gaborone, Botswana, and estimate syphilis prevalence in our clinic sample using this approach. We recruited 390 non-pregnant patients. Participants underwent a combined treponemal and non-treponemal POCT (Dual Path Platform (DPP®) Syphilis Screen and Confirm Assay (Chembio Diagnostic Systems)) on finger-prick blood sample and a questionnaire. Median age 45 years, 30% men, median CD4 count 565 cells/μL, and 91% had an HIV viral load <400 copies/mL. Five participants had active syphilis (1.3%, 95% CI 0.5-3.0%) and 64 had previous syphilis (16.4%, 95% CI 13.0-20.4%) using the DPP POCT. There was a reasonable level of agreement between digital and visual reading of the POCT (kappa statistic of 0.81); however, visual reading missed three active infections (60%). The level of active syphilis was similar to local antenatal data. The DPP POCT led to five participants with active syphilis being diagnosed and starting same-day treatment. The digital reader should be used.

Keywords: Africa; Botswana; HIV; Syphilis; point-of-care test; sexually transmitted infections.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Botswana / epidemiology
  • Female
  • HIV Infections* / complications
  • HIV Infections* / diagnosis
  • HIV Infections* / epidemiology
  • Humans
  • Infant, Newborn
  • Male
  • Point-of-Care Testing
  • Pregnancy
  • Reading
  • Syphilis* / diagnosis
  • Syphilis* / epidemiology