Journal Article

Accuracy of Urine Circulating Cathodic Antigen (CCA) Test for Schistosoma mansoni Diagnosis in Different Settings of Côte d'Ivoire

Silué, Kigbafori D., N'Gbesso, Yve K., Utzinger, Jürg, Coulibaly, Jean T., Brou, Jean K., N'Goran, Eliézer K., N'Guessan, Nicaise A., Knopp, Stefanie, Lohourignon, Laurent K., Vounatsou, Penelope, Fürst, Thomas

2011

Overview

Promising results have been reported for a urine circulating cathodic antigen (CCA) test for the diagnosis of Schistosoma mansoni. We assessed the accuracy of a commercially available CCA cassette test (designated CCA-A) and an experimental formulation (CCA-B) for S. mansoni diagnosis. We conducted a cross-sectional survey in three settings of Côte d'Ivoire: settings A and B are endemic for S. mansoni, whereas S. haematobium co-exists in setting C. Overall, 446 children, aged 8-12 years, submitted multiple stool and urine samples. For S. mansoni diagnosis, stool samples were examined with triplicate Kato-Katz, whereas urine samples were tested with CCA-A. The first stool and urine samples were additionally subjected to an ether-concentration technique and CCA-B, respectively. Urine samples were examined for S. haematobium using a filtration method, and for microhematuria using Hemastix dipsticks. Considering nine Kato-Katz as diagnostic 'gold' standard, the prevalence of S. mansoni in setting A, B and C was 32.9%, 53.1% and 91.8%, respectively. The sensitivity of triplicate Kato-Katz from the first stool and a single CCA-A test was 47.9% and 56.3% (setting A), 73.9% and 69.6% (setting B), and 94.2% and 89.6% (setting C). The respective sensitivity of a single CCA-B was 10.4%, 29.9% and 75.0%. The ether-concentration technique showed a low sensitivity for S. mansoni diagnosis (8.3-41.0%). The specificity of CCA-A was moderate (76.9-84.2%); CCA-B was high (96.7-100%). The likelihood of a CCA-A color reaction increased with higher S. mansoni fecal egg counts (odds ratio: 1.07, p<0.001). A concurrent S. haematobium infection or the presence of microhematuria did not influence the CCA-A test results for S. mansoni diagnosis. CCA-A showed similar sensitivity than triplicate Kato-Katz for S. mansoni diagnosis with no cross-reactivity to S. haematobium and microhematuria. The low sensitivity of CCA-B in our study area precludes its use for S. mansoni diagnosis.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Accuracy / Animals / Antigens, Helminth - urine / Chemotherapy / Child / Clinical Laboratory Techniques - methods / Colleges & universities / Cote d'Ivoire / Cross-Sectional Studies / Diagnosis / Enzyme-linked immunosorbent assay / Feces - chemistry / Female / Glycoproteins - urine / Health facilities / Helminth Proteins - urine / Humans / Immune system / Immunoassay - methods / Infections / Male / Medical diagnosis / Medicine / Parasitology - methods / Prevalence / Prevalence studies (Epidemiology) / Risk factors / Schistosomiasis / Schistosomiasis mansoni - diagnosis / Sensitivity and Specificity / Tropical diseases / Urine - chemistry