Seropositivity for Trypanosoma cruzi infection was studied in 308 street-sweepers of the SLU. Federal District. Brazil, with the aid of haemaglutination. immunofluorescence and, also, a delayed-type skin test to the parasite T12E antigen. It showed 32,1%, 42.7% and 38.6% positive results, respectively for cach assay. Among these, however, only 47% were positive with each of three exams performed. In addition, 19.7% were positive with two out of three exams performed. The remaining 33-3% sera yielded one positive result out of three exams employed and were submitted to the immunoblot assay. This analysis confirmed 3 cases (37.5%) positive by hemmaglutination. 3 (11.5%) positive by skin test, and 1 (3-7%) positive by immunofluorescence. At the end of the analysis, it was shown that 129 (35%) individuals yielded at least two positive assays and therefore, they should be cousidered as T. cruzi-infected individuals.
Human T. cruzi infection; Serology; Delayed-tvpe skin hypersensitivity