Performance of the point-of-care circulating cathodic antigen (POC-CCA) urine cassette test for follow-up after treatment of S. mansoni infection in Eritrean refugees

Background: Point-of-care circulating cathodic antigen (POC-CCA) urine cassette testing has become a popular approach to screen for Schistosoma infection. Since the test is also increasingly used for following-up of treatment success, we assessed the assay's diagnostic accuracy after praziquantel treatment of S. mansoni infection among Eritrean refugees in Switzerland. Methods: In our preceding study, 107 asymptomatic Eritrean refugees in Switzerland were screened for schistosomiasis by stool microscopy, serology, and POC-CCA urine testing. Individuals screened positive by any method were treated with praziquantel and invited for a follow-up visit, repeating the same diagnostic procedures one year after treatment. The POC-CCA baseline and follow-up results were analyzed against the 'baseline microscopy positive cases' (= the most reliably true positive cases) and the 'baseline microscopy plus serology negative cases at baseline and follow-up' (= the most reliably true negative cases). Results: Complete diagnostic baseline and follow-up sampling was available from 48 participants. Compared to most reliably true positive cases at baseline, POC-CCA testing had a sensitivity of 90%. Compared to most reliably true negative cases, POC-CCA testing had a specificity of 73.9%. Conclusion: We conclude that the POC-CCA urine test is valuable for screening but its use is not suitable for routine follow-up after treatment.