Field Evaluation of a Point-of-Care Circulating Cathodic Antigen (POC-CCA) Test for the Detection of Schistosoma japonicum in Indonesia.

BACKGROUND

Schistosomiasis caused by Schistosoma japonicum remains a public health concern in low-endemic areas of Indonesia Sensitive and field-applicable diagnostic tools are essential for effective surveillance and control This study evaluated the diagnostic performance of a point-of-care circulating cathodic antigen (POC-CCA) urine test for detecting S. japonicum infection.

METHODS

A community-based cross-sectional diagnostic evaluation was conducted during August-September 2023 among 226 residents of Wanga (Lore Peore) and Tamadue (Lore Timur) villages, Poso Regency, Central Sulawesi, Indonesia Stool samples were examined using the Kato-Katz (KK) technique, and urine samples were tested using the POC-CCA cassette. Diagnostic accuracy indices were calculated using MedCalc software, with KK serving as the reference standard.

RESULTS

Of the 226 participants, 36 (15.9%) were positive for S. japonicum by KK, whereas only 6 (2.7%) tested positive by POC-CCA. A total of 188 participants were negative by both methods, while 30 were KK-positive but POC-CCA-negative. The sensitivity of the POC-CCA test was 16.67% (95% CI: 6.37-32.81), and specificity was 98.95% (95% CI: 96.25-99.87). The positive predictive value was 75.00% (95% CI: 38.66-93.46), the negative predictive value was 86.24% (95% CI: 84.40-87.89), and Cohen's kappa coefficient was 0.246 (95% CI: 0.004-0.487), indicating fair agreement.

CONCLUSIONS

The POC-CCA urine test demonstrated high specificity but very low sensitivity for detecting S. japonicum, particularly in low-intensity infections. Its use as a standalone diagnostic tool in low-endemic settings is not recommended Refinement of the assay or integration with complementary diagnostic methods is necessary before field application.