Diagnostic accuracy and feasibility of serological tests on filter paper samples for outbreak detection of T.b. gambiense human African trypanosomiasis

Am J Trop Med Hyg. 2010 Aug;83(2):374-9. doi: 10.4269/ajtmh.2010.09-0735.

Abstract

Control of human African trypanosomiasis (HAT) in the Democratic Republic of Congo is based on mass population screening by mobile teams; a costly and labor-intensive approach. We hypothesized that blood samples collected on filter paper by village health workers and processed in a central laboratory might be a cost-effective alternative. We estimated sensitivity and specificity of micro-card agglutination test for trypanosomiasis (micro-CATT) and enzyme-linked immunosorbent assay (ELISA)/T.b. gambiense on filter paper samples compared with parasitology-based case classification and used the results in a Monte Carlo simulation of a lot quality assurance sampling (LQAS) approach. Micro-CATT and ELISA/T.b. gambiense showed acceptable sensitivity (92.7% [95% CI 87.4-98.0%] and 82.2% [95% CI 75.3-90.4%]) and very high specificity (99.4% [95% CI 99.0-99.9%] and 99.8% [95% CI 99.5-100%]), respectively. Conditional on high sample size per lot (> or = 60%), both tests could reliably distinguish a 2% from a zero prevalence at village level. Alternatively, these tests could be used to identify individual HAT suspects for subsequent confirmation.

MeSH terms

  • Agglutination Tests / standards*
  • Antibodies, Protozoan / blood
  • Blood Specimen Collection / instrumentation
  • Blood Specimen Collection / methods
  • Democratic Republic of the Congo / epidemiology
  • Disease Outbreaks*
  • Enzyme-Linked Immunosorbent Assay / standards*
  • Filtration / instrumentation
  • Humans
  • Latex Fixation Tests / standards
  • Monte Carlo Method
  • Paper
  • ROC Curve
  • Sensitivity and Specificity
  • Specimen Handling
  • Trypanosoma brucei gambiense / immunology*
  • Trypanosomiasis, African / diagnosis*
  • Trypanosomiasis, African / epidemiology

Substances

  • Antibodies, Protozoan