DETECTION OF THE CIRCULATING ANTIGENS CAA AND CCA IN A GROUP OF DUTCHTRAVELERS WITH ACUTE SCHISTOSOMIASIS

Detection of circulating anodic antigen (CAA) and circulating cathodic antigen (CCA) in serum and urine is a highly specific and sensitive a lternative for the diagnosis of schistosome infections in endemic area s. However, it is not known how soon after the onset of infection thes e antigens can be detected in humans. Neither has there been much rese arch on the detection of these antigens in individuals normally living in non-endemic areas. We studied the kinetics of CAA and CCA in serum and urine of a group of 28 Dutch tourists, shortly after accidental e xposure to a Schistosoma infection during a visit to Mali. Twenty-seve n were found to be positive for Schistosoma eggs and/or specific antib odies. From each individual, 1-4 serum samples were tested for circula ting antigen level, 4-15 weeks after exposure, and urine samples were also tested from 22 subjects. CAA and CCA levels were quantified by mo noclonal antibody-based ELISAs and TRIFMAs. In serum, 23 individuals ( 85%) were positive at least once for one or both antigens, but titres were generally very low. CAA and CCA could be detected 5 and 6 weeks a fter exposure, respectively. Urines were all found to be negative. Alm ost all cases were negative at 7 months' follow-up.