Use of circulating cathodic antigen strips for the diagnosis of urinary schistosomiasis

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene 2009-01, Vol.103 (1), p.45-51
• Main Authors: Midzi, N., Butterworth, A.E., Mduluza, T., Munyati, S., Deelder, A.M., van Dam, G.J.
• Format: Article
• Language: English
• Subjects: Adolescent; Animals; Anthelmintics - therapeutic use; Antigens, Helminth - urine; Biological and medical sciences; Child; Child, Preschool; Circulating cathodic antigen; Diseases caused by trematodes; Female; General aspects; Helminthic diseases; Humans; Infectious diseases; Male; Medical sciences; Parasite Egg Count; Parasitic diseases; Praziquantel - therapeutic use; Rapid diagnostic tests; Reagent Strips; Rural Health; Schistosoma haematobium; Schistosoma haematobium - immunology; Schistosomiases; Schistosomiasis; Schistosomiasis haematobia - diagnosis; Schistosomiasis haematobia - drug therapy; Screening; Sensitivity and Specificity; Treatment Outcome; Young Adult; Zimbabwe
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1016/j.trstmh.2008.08.018

Rapid diagnostic tests are needed for the implementation and monitoring of national schistosomiasis control programmes. The field applicability of the circulating cathodic antigen (CCA) urine reagent strip for the diagnosis of Schistosoma haematobium infection was evaluated among 265 pre- and primary schoolchildren aged 2–19 years in a rural area of Zimbabwe. The CCA strip was compared with egg detection before and six weeks after treatment with praziquantel. Pre-treatment prevalence (overall 40.4%) and intensity of infection, as determined by egg counts, increased with age. CCA and parasitological results were significantly correlated ( P < 0.001), although concordance was slight (κ = 0.21). Discordant results were mainly attributable to CCA-positive, egg-negative individuals. Correlations and levels of agreement improved significantly with age ( P < 0.001, κ = 0.40) and intensity of infection ( P < 0.001). Praziquantel treatment led to ‘cure’ in 90.9% and 70.5% of children as measured by the egg detection and CCA methods, respectively. An arbitrary gold standard was constructed that included both CCA and egg detection results. Using this standard, the sensitivities of the CCA test were 88.2% and 95.8%, respectively, for pre- and post-treatment results. The improved version that is field applicable now has an acceptable role in the field diagnosis of S. haematobium.