Comparison of ELISA and Urine Microscopy for Diagnosis ofSchistosoma haematobiumInfection

Abstract

BackgroundSchistosoma haematobium which causes urogenital schistosomiasis (UGS) is highly prevalent in African countries. Urine microscopy (UM) is the first-line diagnostic method of UGS. Enzyme-linked immunosorbent assay (ELISA) is a common method for screening many parasite infections primarily or alternatively. The present study established an in-house diagnostic system by ELISA and evaluated its diagnostic efficacy in comparison with UM for screening UGS in White Nile State, Republic of Sudan, 2011–2013.MethodsA total of 490 participants were screened by UM or ELISA, and 149 by both. The in-house ELISA system was established employing soluble egg antigen of S. haematobium and the cut-off absorbance was set at 0.270.ResultsOf the 149 subjects, 58 participants (38.9%) were positive by UM, 119 (79.9%) were positive by ELISA and 82 (55.0%) showed consistently positive or negative results by both methods. The diagnostic sensitivity of ELISA was 94.8% and specificity was 29.7% based on UM results. The ELISA positive serum samples also cross-reacted with egg antigens of Schistosoma mansoni and Schistosoma japonicum.ConclusionWe have established in-house ELISA for screening serum immunoglobulin (Ig) G antibodies by employing soluble egg antigen of S. haematobium for diagnosis of UGS with 94.8% sensitivity and 29.7% specificity. The ELISA system can supplement the conventional diagnosis by UM.