Antibody detection
Antibody detection can be useful to indicate schistosome infection in patients who have traveled in schistosomiasis endemic areas and in whom eggs cannot be demonstrated in fecal or urine specimens.  Test sensitivity and specificity vary widely among the many tests reported for the serologic diagnosis of schistosomiasis and are dependent on both the type of antigen preparations used (crude, purified, adult worm, egg, cercarial) and the test procedure.

At CDC, a combination of tests with purified adult worm antigens is used for antibody detection.  All serum specimens are tested by FAST-ELISA using Schistosoma mansoni adult microsomal antigen (MAMA).  A positive reaction (greater than 8 units/µl serum) indicates infection with Schistosoma species.  Sensitivity for S. mansoni infection is 99%, 95% for Schistosoma haematobium infection, and <50% for Schistosoma japonicum infection.  Specificity of this assay for detecting schistosome infection is 99%.  Because test sensitivity with the FAST-ELISA is reduced for species other than S. mansoni, immunoblots of the species appropriate to the patient's travel history are also tested to ensure detection of S. haematobium and S. japonicum infections.  Immunoblots with adult worm microsomal antigens are species-specific and so a positive reaction indicates the infecting species.  The presence of antibody is indicative only of schistosome infection at some time and cannot be correlated with clinical status, worm burden, egg production, or prognosis.  When submitting specimens, please include the patient's travel history so the appropriate schistoma species will be tested by immunoblot.

Reference:

Tsang VC, Wilkins PP. Immunodiagnosis of schistosomiasis. Immunol Invest 1997;26:175-188.