Inadequate Clearance of Circulating Cathodic Antigen Following Single-Dose Praziquantel Treatment Among Pre- and School-Aged Children in Schistosoma mansoni Hyper-Endemic Areas of North-Western Tanzania

Abstract

Background: Praziquantel (PZQ) remains the primary drug for treating schistosomiasis, with its efficacy traditionally measured using the Kato-Katz technique. However, these methods have limitations, prompting interest in point-of-care circulating cathodic antigen (POC-CCA) tests as an alternative diagnostic tool. This study aimed to assess the efficacy of praziquantel in clearing circulating cathodic antigen (CCA) among pre- and school-aged children in a S. mansoni hyper-endemic area of North-Western Tanzania.
Methods: A longitudinal study was conducted among 161 children aged 2–17 years. Participants were screened for S. mansoni infection using Kato-Katz and POC-CCA tests at baseline and 21 days post-treatment with a single dose of PZQ (40 mg/kg). Cure rates (CR) and egg reduction rates (ERR) were calculated.
Results: The overall prevalence of S. mansoni was 98 (70.0%) (Kato-Katz) and 114 (70.8%) (POC-CCA). The parasitological cure rate (PCR) was 61 (66.3%) (Kato-Katz) and 27 (27.6%) (POC-CCA), with an ERR of 73.6%. Significant differences were observed between the two diagnostic methods.
Conclusion: While PZQ demonstrated adequate efficacy based on Kato-Katz results, poor CCA clearance highlights the need for improved diagnostics and monitoring strategies in schistosomiasis control programs.