Parasite persistence in treated chagasic patients revealed by xenodiagnosis and polymerase chain reaction

• Autor(a) principal: Britto, Constança
• Data de Publicação: 2001
• Outros Autores: Silveira, Celeste Aída Nogueira, Cardoso, Maria Angelica, Marques, Patricia, Ostermayer, Alejandro Luquetti, Macêdo, Vanize de Oliveira, Fernandes, Octavio
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UnB
• Texto Completo: http://repositorio.unb.br/handle/10482/25702; https://dx.doi.org/10.1590/S0074-02762001000600014
• topic: Trypanosoma cruzi; DNA de cinetoplasto; Chagas, Doença de; PCR; Tratamento

Polymerase chain reaction (PCR) was compared with xenodiagnosis performed 20 years after trypanocidal chemotherapy to investigate parasite clearance. Eighty-five seropositive individuals for Chagas disease presenting a positive xenodiagnosis were treated with specific drugs; 37 in the acute phase and 48 in the chronic phase. Fifteen chronic assymptomatic patients received a placebo. Treatment in the acute phase led to PCR negative results in 73% of the cases, while xenodiagnosis was negative in 86%. In the chronic phase, PCR was negative in 65% of the patients and 83% led to xenodiagnosis negative results. Regarding the untreated group (placebo), 73% gave negative results by xenodiagnosis, of which 36% were positive by PCR. Individuals that were considered seronegative (n=10), presented unequivocally negative results in the PCR demonstrating the elimination of parasite DNA. Seventeen individuals had their antibodies titers decreased to such a level that the final results were considered as doubtful and 16 of them presented negative PCR. The molecular method represents a clear advantage over conventional techniques to demonstrate persistent infections in Chagas disease patients that underwent chemotherapy.