DAY-TO-DAY FLUCTUATION OF SCHISTOSOME CIRCULATING ANTIGEN LEVELS IN SERUM AND URINE OF HUMANS INFECTED WITH SCHISTOSOMA-MANSONI IN BURUNDI

Day-to-day fluctuations of both circulating anodic antigen (CAA) and c irculating cathodic antigen (CCA) in serum and urine were examined sim ultaneously in a group of Schistosoma mansoni-infected individuals fro m Burundi and compared with each other and with fecal egg count fluctu ations. Significant correlations were found between fecal egg counts a nd circulating antigens (CAA and CCA) and between circulating antigen levels in serum and urine samples. The cumulative percentage of positi ve results after three samplings was highest for urine CCA detection, followed by fecal egg counts, serum CCA, serum CAA, and urine CAA dete ction, respectively. It was demonstrated that circulating antigen leve ls in both serum and urine showed less fluctuation than fecal egg coun ts, except for urine CAA levels. The serum CAA detection assay in part icular, although less sensitive in this low endemic area in Burundi, g ave very constant measurements over a period of one week. Our results indicate that detection of circulating antigens in a single serum or u rine sample provides a quantitatively more stable diagnosis of S. mans oni infection than fecal egg counts based on a single stool examinatio n.