Evaluation of parasitemia by qPCR in patients with chronic Chagas disease treated with benznidazole

Abstract

Objective: To evaluate parasitemia by qPCR in patients undergoing etiological treatment and followed in a Brazilian reference center. Methods: Parasite load was quantified by qPCR in 32 participants with chronic Chagas disease who were treated with benznidazole. Serological analyses were performed before and after the treatment and parasite loads were compared prior and 12/18 months post the treatment. Results: Thirty-two participants were recruited and treated with benznidazole, and 20 were followed-up. Adverse events (AE) were observed in 22 out of 29 participants that had safety data (76%), and dermatological alterations were the most frequently observed AE. Of the 20 participants analyzed, 13 and 7 completed 12 and 18 months follow-up after the treatment, respectively. 12 Months after the final treatment, Trypanosoma cruzi was detectable in 3 patients by qPCR; 18 months after the final treatment, Trypanosoma cruzi was detectable per qPCR in 4 of the 7 participants. Thus, between 12 and 18 months, 7 participants of the 20 initial follow-up cases showed positive qPCR, indicating treatment failures. Conclusions: qPCR can be used as an alternative method for evaluating the effectiveness of the etiological treatment of CD, and can be applied to analyze early therapeutic failures. The study showed that benznidazole therapy had limited effectiveness in treating chronic CD patients, thus emphasizing the importance of conducting continued research for developing more effective therapies and diagnosis for CD.

Keywords

• trypanosoma cruzi; chagas disease; antitrypanosomal therapy; benznidazole; qpcr; therapeutic failure