Validation of a Point-of-Care Circulating Cathodic Antigen Urine Cassette Test for Schistosoma mansoni Diagnosis in the Sahel, and Potential Cross-Reaction in Pregnancy

Am J Trop Med Hyg. 2016 Feb;94(2):361-4. doi: 10.4269/ajtmh.15-0577. Epub 2015 Nov 10.

Abstract

On the shores of Lake Chad, schistosomiasis among mobile pastoralists was investigated in a field laboratory. Point-of-care circulating cathodic antigen (POC-CCA) cassette test, reagent strip, and filtration were conducted on urine samples. Fresh stool samples were subjected to the Kato-Katz technique, and fixed samples were examined with an ether-concentration method at a reference laboratory. POC-CCA urine cassette tests revealed a Schistosoma mansoni prevalence of 6.9%, compared with only 0.5% by stool microscopy. Three pregnant women with otherwise negative urine and stool testing had positive POC-CCA. This observation raises concern of cross-reactivity in pregnancy. Hence, two pregnant women in Switzerland with no history of schistosomiasis were subjected to POC-CCA and one tested positive. Our data suggest that POC-CCA can be performed under extreme Sahelian conditions (e.g., temperatures > 40°C), and it is more sensitive than stool microscopy for S. mansoni diagnosis. However, potential cross-reactivity in pregnancy needs further investigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Antigens, Helminth
  • Clinical Laboratory Techniques / methods
  • Cross Reactions
  • Feces / parasitology
  • Female
  • Filtration / methods
  • Humans
  • Male
  • Middle Aged
  • Parasitology / methods
  • Point-of-Care Systems
  • Pregnancy
  • Reagent Strips
  • Reproducibility of Results
  • Schistosoma mansoni
  • Schistosomiasis mansoni / diagnosis*
  • Schistosomiasis mansoni / urine*
  • Sensitivity and Specificity
  • Young Adult

Substances

  • Antigens, Helminth
  • Reagent Strips