RESUMO
A randomized ten-year follow-up study involving 91 Chagas patients and 41 uninfected controls was undertaken to determine the effectiveness of nitroderivative therapy. Anti-Trypanosoma cruzi antibodies were consistently lower one year after treatment than 10 years thereafter (P < 0.001). The blood of all treated and 93.7% of untreated Chagas patients yielded polymerase chain reaction (PCR) product from probes annealing to T. cruzi nuclear DNA, indicating active infection. Competitive PCR showed means +/- standard deviations of 20.1+/-22.6 T. cruzi/ml of blood from untreated and 13.8+/-14.9 from treated Chagas patients, but the differences between means were not statistically significant (P > 0.05). Electrocardiograms recorded a gamut of alterations several-fold more frequent in Chagas patients, regardless of treatment, than in uninfected controls (P < 0.001). These results show that nitroderivative therapy for T. cruzi infections is unsatisfactory and cannot be recommended since it fails to eradicate the parasite or change the progression of heart disease in chronic Chagas patients.
Assuntos
Anticorpos Antiprotozoários/sangue , Cardiomiopatia Chagásica/tratamento farmacológico , Tripanossomicidas/uso terapêutico , Trypanosoma cruzi/imunologia , Adulto , Animais , Estudos de Casos e Controles , Doença Crônica , Primers do DNA , Progressão da Doença , Eletrocardiografia , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Seguimentos , Testes de Hemaglutinação , Humanos , Masculino , Pessoa de Meia-Idade , Nifurtimox/uso terapêutico , Nitroimidazóis/uso terapêutico , Reação em Cadeia da Polimerase , Resultado do TratamentoRESUMO
Seropositivity for Trypanosoma cruzi infection was studied in 368 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%, 42.1% and 38.6% positive results, respectively for each 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 considered as T. cruzi-infected individuals.