PRETREATMENT AND POSTTREATMENT IMMUNODIAGNOSTIC EVALUATION IN HUMAN SCHISTOSOMIASIS-MANSONI

Schistosomiasis control seems to be different in countries were low pa rasitic burden and asymptomatic clinical patients are the features of majority of cases. Immunological methods must substitute the tradition al coprologic techniques used for some decades in the Control Program. Circumoval Precipitin Test (COPT), intradermal test and ELISA with so luble egg antigen (SEA) are evaluated for using as tools for seroepide miologic studies. COPT and ELISA were performed after treatment to kno wn their utility when impact of chemotherapy must be assessed One hund red sixty five persons were followed up 3, 6, 9 and 12 months after tr eatment. The mean sensitivity of COPT studied by age groups was 95.6% which is very important considering that 88.4% of the studied populati on excreted less than 100 eggs/gr of feces, while sensitivity of intra dermal test was 58.2%. Children showed the highest ractivity to COPT. When treatment is effective, COPT reactivity progressively disminish u ntil become negative one year later. In the non cure group, the COPT r eactivity disminished but never below 20%. ELISA-SEA did not modify on e year after treatment. Effort should be made to isolate fractions of eggs of Schistosoma mansoni whose antibodies disappear after treatment .