Evaluation of circulating cathodic antigen (CCA) urine-cassette assay as a survey tool for Schistosoma mansoni in different transmission settings within Bugiri District, Uganda
Makerere University School of Public Health, P.O. Box 7026, Kampala, Uganda; Vector Control Division, Ministry of Health, P.O. Box 1661, Plot 15 Bombo Road, Kampala, Uganda; Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, United States; Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, United Kingdom; Parasitology Department, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom; Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 6HT, United Kingdom
Diagnosis of schistosomiasis at the point-of-care (POC) is a growing topic in neglected tropical disease research. There is a need for diagnostic tests which are affordable, sensitive, specific, user-friendly, rapid, equipment-free and delivered to those who need it, and POC is an important tool for disease mapping and guiding mass deworming. The aim of present study was to evaluate the relative diagnostic performance of two urine-circulating cathodic antigen (CCA) cassette assays, one commercially available and the other in experimental production, against results obtained using the standard Kato-Katz faecal smear method (six thick smears from three consecutive days), as a 'gold-standard', for Schistosoma mansoni infection in different transmission settings in Uganda. Our study was conducted among 500 school children randomly selected across 5 schools within Bugiri district, adjacent to Lake Victoria in Uganda. Considering results from the 469 pupils who provided three stool samples for the six Kato-Katz smears, 293 (76%) children had no infection, 109 (23%) were in the light intensity category, while 42 (9%) and 25 (5%) were in the moderate and heavy intensity categories respectively. Following performance analysis of CCA tests in terms of sensitivity, specificity, negative and positive predictive values, overall performance of the commercially available CCA test was more informative than single Kato-Katz faecal smear microscopy, the current operational field standard for disease mapping. The current CCA assay is therefore a satisfactory method for surveillance of S. mansoni in an area where disease endemicity is declining due to control interventions. With the recent resolution on schistosomiasis elimination by the 65th World Health Assembly, the urine POC CCA test is an attractive tool to augment and perhaps replace the Kato-Katz sampling within ongoing control programmes. © 2014 Elsevier B.V.
praziquantel; CCA protein, Schistosoma mansoni; glycoprotein; helminth protein; parasite antigen; antigen; bioassay; disease; disease control; mapping; schistosomiasis; testing method; adolescent; article; bioassay; child; circulating cathodic antigen cassette assay; controlled study; diagnostic test accuracy study; disease control; disease transmission; feces analysis; female; gold standard; human; intermethod comparison; Kato Katz fecal smear method; laboratory diagnosis; major clinical study; male; point of care testing; predictive value; prevalence; quality control; randomized controlled trial; Schistosoma mansoni; schistosomiasis mansoni; sensitivity and specificity; Uganda; urinalysis; animal; epidemiology; isolation and purification; schistosomiasis mansoni; urine; Uganda; Adolescent; Animals; Antigens, Helminth; Child; Female; Glycoproteins; Helminth Proteins; Humans; Male; Predictive Value of Tests; Schistosoma mansoni; Schistosomiasis mansoni; Sensitivity and Specificity; Uganda