Semi-quantitative scoring of an immunochromatographic test for circulating filarial antigen

Am J Trop Med Hyg. 2013 Nov;89(5):916-8. doi: 10.4269/ajtmh.13-0245. Epub 2013 Sep 9.

Abstract

Abstract. The value of a semi-quantitative scoring of the filarial antigen test (Binax Now Filariasis card test, ICT) results was evaluated during a field survey in the Republic of Congo. One hundred and thirty-four (134) of 774 tests (17.3%) were clearly positive and were scored 1, 2, or 3; and 11 (1.4%) had questionable results. Wuchereria bancrofti microfilariae (mf) were detected in 41 of those 133 individuals with an ICT test score ≥ 1 who also had a night blood smear; none of the 11 individuals with questionable ICT results harbored night mf. Cuzick's test showed a significant trend for higher microfilarial densities in groups with higher ICT scores (P < 0.001). The ICT scores were also significantly correlated with blood mf counts. Because filarial antigen levels provide an indication of adult worm infection intensity, our results suggest that semi-quantitative reading of the ICT may be useful for grading the intensity of filarial infections in individuals and populations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Animals
  • Antigens, Helminth / blood*
  • Cell Count
  • Child
  • Child, Preschool
  • Congo / epidemiology
  • Enzyme-Linked Immunosorbent Assay
  • Filariasis / blood
  • Filariasis / diagnosis*
  • Filariasis / epidemiology
  • Filariasis / parasitology
  • Humans
  • Microfilariae / immunology
  • Microfilariae / isolation & purification*
  • Middle Aged
  • Reagent Kits, Diagnostic
  • Research Design
  • Wuchereria bancrofti / immunology
  • Wuchereria bancrofti / isolation & purification*

Substances

  • Antigens, Helminth
  • Reagent Kits, Diagnostic