Limited field evaluation of a rapid monoclonal antibody-based dipstick assay for urinary schistosomiasis.

Abstract

A rapid, visually read monoclonal antibody (MoAb)-based dipstick assay for specific diagnosis of urinary schistosomiasis was field tested with microscopy and the use of hematuria and proteinuria in a schistosomiasis hematobia endemic area in Southern Ghana. The study group consisted of 229 individuals (114 males and 115 females) aged 1 to 86 years; 145/229 (63.3%) of the subjects submitted stool samples from which no S. mansoni eggs were detected. However, infections with Necator americanus (hookworms) 33.1%, Ascaris lumbricoides 2.8%, Trichuris trichiura (whipworm) 2.8%, and Strongyloides stercoralis 0.7% were detected but did not appear to influence the results of the MoAb-dipstick assay. Urinary schistosomiasis prevalence was estimated as 47.6% by microscopy, 48% by MoAb-dipstick, 39.7% by microhematuria, and 23.6% by proteinuria. The MoAb-dipstick correctly identified 108/109 (99.1%) of microscopically confirmed cases and 118/120 (98.3%) of egg-negative individuals, thereby giving a sensitivity of 99.1% and a specificity of 98.3%. On the other hand, microhematuria and proteinuria were, respectively, 76.1% and 40.4% sensitive, and 94.2% and 92.5% specific when compared to microscopy. Microhematuria and proteinuria had significantly lower sensitivity (P < 0.001) than either microscopy or dipstick.