A monoclonal antibody-based dipstick assay for diagnosis of urinary schistosomiasis

Abstract

A Schistosoma haematobium species-specific mouse immunoglobulin (Ig) G1 monoclonal antibody (mab) Sh2/15.F that bound a 29 kDa peptide was utilized to develop a membrane-based dipstick enzyme-linked immunosorbent assay for specific diagnosis of urinary schistosomiasis. Strips of polyvinylidene difluoride membrane were wetted with methanol and stored in distilled water. The strips were used to capture urinary antigens which were then revealed by incubation in a mixture of specific mab and peroxidase-conjugated goat anti-mouse IgG. The assay correctly identified (87%) of egg-negative control individuals and (98%) of parasitologically confirmed cases including all of 6 individuals treated with praziquantel (40 mg/kg) but not cured. Also, the assay detected S. haematobium antigens in the urine of 3 individuals from whom 2 specimens had to be examined microscopically to confirm infection, thus suggesting that the mab detection method may have greater sensitivity than microscopy.