Two soluble antigens isolated from T. cruzi were evaluated by ELISA for the diagnosis of chronic infection and assessment of cure after specific chemotherapy, namely, supernatants from parasite cell-cultures (SpAg) arid trypomastigote excretory /secretory antigens (ESAg). Among the treated patients, a group defined as "dissociated " had been monitored for 3 to 10 years and displayed negative hemocultures and tests of trypomastigote complement-mediated lysis persistently negative although positive by conventional serology (indirect fluorescence with epimastigote, mainly). A negative lysis test indicates parasite elimination by the patient. Our ELISA results showed that among the non-treated chagasic controls the SpAg e ESAg detected 93% and 100%, of the cases, respectively. However, only 28% of sera from the dissociated group, considered as cured, were positive by ELISA using SpAg whereas all of such sera were negative using ESAg. Therefore ELISA with ESAg seems to be ideal to replace the complement- mediated lysis test with the aim to define cure after treatment of the chronic infection by T. cruzi.
Trypanosoma cruzi; Soluble antigens of trypomastigotes; Chagasic patients; Treatment and cure; ELISA