Parasitological cure and clinical benefits of benznidazole treatment in patients from the Jequitinhonha Valley, MG, Brazil, with recent chronic infection by Trypanosoma cruzi II

Abstract

Background: The treatment of the early chronic phase of Chagas disease (CD) may result in high rates of parasitological cure, which may be associated with clinical benefits.

Objectives: To evaluate children with CD from the Jequitinhonha Valley, MG, Brazil, treated with benznidazole (BZ), employing classic and alternative methodologies.

Methods: Before and after treatment, nine individuals were examined by haemoculture, polymerase chain reaction (PCR), conventional enzyme-linked immunosorbent assay (ELISA), electrocardiogram, echocardiogram, and thoracic and gastrointestinal X-ray. Eight individuals were in the indeterminate clinical form of CD, and one was in the mild cardiac form. After treatment, all individuals were re-evaluated periodically for 4-26 years using the same methodologies cited and anti-live trypomastigotes antibodies by flow-cytometry-FC-ALTA and quantitative PCR (qPCR).

Findings: The cure rate by the classic cure criteria was 33.33%. By the alternative cure criteria using FC-ALTA and qPCR, the rates of cure were 50% and 78%, respectively. Post-treatment clinical evaluations revealed stability in 5/9 and discrete clinical evolution in 4/9 individuals.

Main conclusions: It was demonstrated the effectiveness of BZ treatment in recent chronic infections of CD with low or higher rates of parasitological cure according to the cure criterion used after long-term follow-up. The clinical status of the individuals remained stable or evolved slowly, suggesting clinical benefits from BZ treatment.

Fig. 1:. Chagas disease patients - Prospective laboratory and clinical follow-up after benznidazole (BZ) treatment.

Fig. 2:. long-term follow-up of Chagas disease patients treated with benznidazole (BZ) in the recent chronic infection by parasitological (haemoculture), conventional serology enzyme-linked immunosorbent assay (ELISA), non-conventional serology (flow cytometry anti-live trypomastigote antibodies - FC-ALTA), and molecular polymerase chain reaction (PCR) and quantitative PCR (qPCR) methods.

Fig. 3:. long-term follow-up of Chagas disease patients treated with benznidazole (BZ) in the recent chronic infection by conventional enzyme-linked immunosorbent assay (ELISA) and non-conventional (flow cytometry anti-live trypomastigote antibodies - FC-ALTA) serologies and molecular [quantitative polymerase chain reaction (qPCR)] methods.