Specificity of the Point-of-Care Urine Strip Test for Schistosoma Circulating Cathodic Antigen (POC-CCA) Tested in Non-Endemic Pregnant Women and Young Children

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  • 1 Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands;
  • 2 Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands;
  • 3 Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands

The point-of-care urine based strip test for the detection of circulating cathodic antigen (POC-CCA) in schistosome infections is a frequently used tool for diagnosis and mapping of Schistosoma mansoni in school-aged children. Because of its ease of use, the test is increasingly applied to adults and preschool-aged children (PSAC), but its performance has not been specifically evaluated in these target groups. Recent observations have raised concerns about possible reduced specificity, in particular in pregnant women (PW) and PSAC. We thus explored specificity of the POC-CCA urine strip test (Rapid Medical Diagnostics, Pretoria, South Africa) in a non-endemic, nonexposed population of 47 healthy nonpregnant adults (NPAs), 52 PW, and 58 PSAC. A total of 157 urines were tested with POC-CCA, of which five (10.6%) NPAs, 17 (32.7%) PW, and 27 (46.5%) PSAC were positive. The highest scores were found in the youngest babies, with an infant of 9 months being the oldest positive case. On measuring pH, it appeared that all POC-CCA strongly positive urines were acidic (pH range 5–5.5), whereas addition of pH-neutral buffer to a subsample reversed the false positivity. We conclude that the POC-CCA test has reduced specificity in PW and infants younger than 9 months, but that the false positivity might be eliminated by modifications in the buffers used in the test.

Author Notes

Address correspondence to Miriam Casacuberta-Partal, Department of Parasitology, Leiden University Medical Centre, P.O. Box 9600, Leiden 2333 ZA, The Netherlands. E-mail: m.casacuberta_partal@lumc.nl

Authors’ addresses: Miriam Casacuberta-Partal, Margreet Beenakker, Pytsje Hoekstra, Lisa Kroon, Dieuwke Kornelis, Cornelis H. Hokke, Govert van Dam, and Lisette van Lieshout, Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands, E-mails: m.casacuberta_partal@lumc.nl, margreetbeenakker@gmail.com, p.t.hoekstra-mevius@lumc.nl, lisajkroon@gmail.com, d.kornelis@lumc.nl, c.h.hokke@lumc.nl, g.j.van_dam@lumc.nl, and e.a.van_lieshout@lumc.nl. Claudia de Dood, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands, E-mails: c.j.de_dood@lumc.nl and p.l.a.m.corstjens@lumc.nl. Meta Roestenberg, Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands, and Department of Infectious Diseases, Leiden University Medical Centre, Leiden, The Netherlands, E-mail: m.roestenberg@lumc.nl.

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