Comparison of Schistosoma mansoni Soluble Cercarial Antigens and Soluble Egg Antigens for Serodiagnosing Schistosome Infections

Abstract

A Schistosoma mansoni cercarial antigen preparation (cercarial transformation fluid – SmCTF) was evaluated for detection of anti-schistosome antibodies in human sera in 4 collaborating laboratories. The performance of SmCTF was compared with that of S. mansoni egg antigens (SmSEA) in an indirect enzyme-immunoassay (ELISA) antigen assay, the latter being used routinely in 3 of the 4 participating laboratories to diagnose S. mansoni and S. haematobium infections. In the fourth laboratory the performance of SmCTF was compared with that of S. japonicum egg antigens (SjSEA) in ELISA for detection of anti-S. japonicum antibodies. In all 4 laboratories the results given by SmCTF in ELISA were very similar to those given by the antigen preparation routinely used in the respective laboratory to detect anti-schistosome antibodies in human infection sera. In so far as the ELISA results from SmCTF are thus so little different from those given by schistosome egg antigens and also cheaper to produce, the former is a potentially useful new diagnostic aid for schistosomiasis.

Advances in the Diagnosis of Human Schistosomiasis

“…Reactivity between antibodies in patient serum and extracted antigens from different life cycle stages of schistosomes can be tested by ELISA; SEA, larval antigens, and AWA have been used effectively in this assay (100,(127)(128)(129)). An S. mansoni cercarial antigen preparation (SmCTF) was successfully evaluated in an indirect ELISA for detection of antischistosomal antibodies in human sera (100). However, since the use of crude whole-parasite extracts increases the antibody cross-reactivity with other helminthic infections and leads to reduced specificity, purified antigens have been used to improve performance.…”

Detection of Schistosoma mansoni Antibodies in a Low-Endemicity Area Using Indirect Immunofluorescence and Circumoval Precipitin Test

“…48,50,51 Cross-reactivity with cercariae antigens from organisms that infect other species of animals are possible, 29 as are cross-reaction with other parasites. 15,36,52 53,54 and a decrease in sensitivity in infections with low parasite load. 35,36 The Kato and Miura technique, 25 modified by Katz and others 7 has become the international reference standard by the WHO.…”

Evaluation of microscopical and serological techniques in the diagnosis of Schistosoma mansoni infection at Sennar State, Central Sudan

“…People are at risk of infection due to agricultural, domestic and recreational activities which expose them to infested water [2] . The highest rates of schistosomal infections are commonly found among children and young adults and in recognition of these schoolchildren are the main target of schistosomiasis control programmes [4] .…”