Evaluation of point-of-contact circulating cathodic antigen assays for the detection of Schistosoma mansoni infection in low-, moderate-, and high-prevalence schools in western Kenya

Am J Trop Med Hyg. 2015 Jun;92(6):1227-32. doi: 10.4269/ajtmh.14-0643. Epub 2015 Apr 13.

Abstract

We evaluated the performance of a point-of-contact circulating cathodic antigen assay (POC-CCA) to detect schistosome infections in primary school children (N = 1,801) living in areas with low, moderate, and high Schistosoma mansoni prevalence in western Kenya. The commercially available assay (CCA-1) and a second, experimental formulation (CCA-2) were compared against Kato-Katz stool examinations and an anti-schistosome enzyme-linked immunosorbent assay (ELISA). A latent class model based on the four tests was used to establish "true infection status" in three different zones based on their distance from Lake Victoria. As a screening tool for community treatment according to World Health Organization (WHO) guidelines, the Kato-Katz examination was in closest agreement with the latent class model, followed by the experimental CCA-2, soluble adult worm antigen preparation (SWAP) ELISA, and CCA-1, which had high sensitivity compared with the other tests but was consistently the least specific. Our experience suggests that POC-CCA tests offer a field-friendly alternative to Kato-Katz, but need further interpretation for appropriate field use.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antigens, Protozoan / urine*
  • Child
  • Enzyme-Linked Immunosorbent Assay
  • Feces / parasitology
  • Female
  • Humans
  • Kenya / epidemiology
  • Lakes / parasitology
  • Male
  • Parasite Egg Count
  • Prevalence
  • Reagent Kits, Diagnostic / parasitology*
  • Reagent Kits, Diagnostic / standards
  • Reproducibility of Results
  • Schistosoma mansoni*
  • Schistosomiasis mansoni / diagnosis*
  • Schistosomiasis mansoni / epidemiology
  • Schistosomiasis mansoni / urine
  • Schools / statistics & numerical data*
  • Sensitivity and Specificity

Substances

  • Antigens, Protozoan
  • Reagent Kits, Diagnostic