Field performance of a thin-layer chromatography assay for detection of nevirapine in umbilical cord blood.

Academic Article

Abstract

  • PURPOSE: Although cord blood surveillance can measure the effectiveness of nevirapine (NVP)-based programs for the prevention of mother-to-child HIV transmission (PMTCT), it requires the ability to detect nevirapine in plasma. At present, the only validated method is high-performance liquid chromatography (HPLC), a technique poorly suited for most resource-constrained settings. METHOD: We evaluated the field performance for a simple and inexpensive thin-layer chromatography (TLC) assay for NVP detection. We developed a conditional probability model to compare 2 testing algorithms: HPLC alone, and TLC screening followed by HPLC confirmation of negative results. RESULTS: When compared to HPLC, sensitivity of TLC was 0.67 (95% confidence interval [CI] 0.49-0.84) and specificity was 0.84 (95% CI 0.69-0.95). In this sample - where overall NVP coverage was 49% - positive predictive value was 0.80 and negative predictive value was 0.72. At baseline with population NVP coverage of 33%, cost per specimen was lower in the TLC-HPLC testing algorithm (40 dollars vs. 50 dollars), and the proportion of false results was acceptable (11%). As population NVP coverage increased, cost-efficiency improved and error rate dropped substantially. CONCLUSION: TLC is reasonably sensitive and specific for NVP detection. A 2-step testing algorithm incorporating TLC and HPLC provides cost-efficiency at little expense to test performance.
  • Published In

    Keywords

  • Algorithms, Anti-HIV Agents, Chromatography, High Pressure Liquid, Chromatography, Thin Layer, Cost-Benefit Analysis, Female, Fetal Blood, HIV, HIV Infections, Humans, Infant, Newborn, Infectious Disease Transmission, Vertical, Nevirapine, Pregnancy, Pregnancy Complications, Infectious, Prospective Studies, Sensitivity and Specificity, Treatment Outcome, Zambia
  • Digital Object Identifier (doi)

    Author List

  • Chi BH; Lee A; Acosta EP; Westerman LE; Sinkala M; Stringer JSA
  • Start Page

  • 263
  • End Page

  • 269
  • Volume

  • 7
  • Issue

  • 5