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

Abstract

BackgroundPromising 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.MethodologyWe 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.Principal FindingsConsidering 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.Conclusion/SignificanceCCA-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.

Epidemiology of Schistosomiasis in Two High-Risk Communities of South Côte d'Ivoire with Particular Emphasis on Pre-School–Aged Children

“…S. mansoni and S. haematobium are coendemic in this area. 16,18 Population census and sample size calculation. A detailed census was carried out in June of 2011 as follows.…”

“…First, we assumed a prevalence of Schistosoma (either S. mansoni or S. haematobium) of 20% among pre-school-aged children (i.e., approximately one-quarter of the 80% S. mansoni infection prevalence observed in schoolaged children in Azaguié in 2010). 16 Second, we allowed for a relatively low compliance rate (70%) because of the difficulty of obtaining stool and urine samples from pre-school-aged children. Third, we considered an α-error of 5%.…”

“…Recent studies carried out in the Azaguié district, south Cô te d'Ivoire, revealed that both Schistosoma mansoni and S. haematobium coexist, and particularly high levels of coinfections were found in the villages of Azaguié Makouguié and Azaguié M'Bromé. 15,16 However, the epidemiology of schistosomiasis and risk factors for early childhood infection have not been investigated in this part of Cô te d'Ivoire. To fill this gap, we designed a cross-sectional parasitologic and questionnaire survey to determine the prevalence and intensity of S. mansoni and S. haematobium infection in pre-schoolaged children, including risk factors for early child infection.…”

Cost Analysis of Tests for the Detection of Schistosoma mansoni Infection in Children in Western Kenya

“…12,13 The POC-CCA assay is commercially available through Rapid Medical Diagnostics (Pretoria, South Africa), and has been evaluated for sensitivity, specificity, and ease of use in a number of settings. [14][15][16][17][18][19] However, there has been concern that the cost of the POC-CCA assay may be a barrier to widespread adoption of this technique for schistosomiasis control programs 14,16,17,20 ; therefore, there is a need for a comprehensive evaluation of the cost-effectiveness of the POC-CCA technique in relation to other available tests. 13 Although the cost of the materials and equipment are commonly cited as expenses, other cost contributions such as labor and transportation are rarely discussed.…”

Diagnosing schistosomiasis: where are we?

“…In Côte d'Ivoire, the sensitivity of triplicate Kato-Katz was 47.9%, 73.9% and 94.2% for the settings A, B (both endemic for S. mansoni) and C (where S. haematobium co-exists) in comparison with one CCA test, that performed at sensitivity levels of 56.3, 69.6 and 89.6%, respectively. The specificity of CCA test was moderate (76.9-84.2%) 70 . In the Lake Victoria region of western Kenya, where S. mansoni infection is prevalent and S. haematobium is not, CCA test was compared to Kato-Katz in 484 children, with sensitivity of 94.2% and specificity of 59.4%.…”