Background Chagas disease (caused by Trypanosoma cruzi infection) evolves to chronic chagasic cardiomyopathy (CCC) affecting 1.8 million people worldwide. This is the first randomized, placebo-controlled, double-blinded, clinical trial designed to estimate efficacy and safety of selenium (Se) treatment in CCC. Methods 66 patients with CCC stages B1 (left ventricular ejection fraction [LVEF] > 45% and no heart failure; n = 54) or B2 (LVEF < 45% and no heart failure; n = 12) were randomly assigned to receive 100 mcg/day sodium selenite ( Se, n = 32) or placebo ( Pla, n = 34) for one year (study period: May 2014-September 2018). LVEF changes over time and adverse effects were investigated. Trial registration number: NCT00875173 (clinicaltrials.gov). Findings No significant differences between the two groups were observed for the primary outcome: mean LVEF after 6 (β = +1.1 p = 0.51 for Se vs Pla ) and 12 months (β = +2.1; p = 0.23). In a subgroup analysis, statistically significant longitudinal changes were observed for mean LVEF in the stage B2 subgroup (β= +10.1; p = 0.02 for Se [ n = 4] vs Pla [ n = 8]). Se treatment was safe for CCC patients, and the few adverse effects observed were similarly distributed across the two groups. Interpretation Se treatment did not improve cardiac function (evaluated from LVEF) in CCC. However, in the subgroup of patients at B2 stage, a potential beneficial influence of Se was observed. Complementary studies are necessary to explore diverse Se dose and/or associations in different CCC stages (B2 and C), as well as in A and B1 stages with longer follow-up. Funding Brazilian Ministry of Health, Fiocruz, CNPq, FAPERJ.

A doença de Chagas é uma condição crônica negligenciada com elevada carga de morbimortalidade e impacto dos pontos de vista psicológico, social e econômico. Representa um importante problema de saúde pública no Brasil, com diferentes cenários regionais. Este documento traduz a sistematização das evidências que compõe o Consenso Brasileiro de Doença de Chagas. O objetivo foi sistematizar estratégias de diagnóstico, tratamento, prevenção e controle da doença de Chagas no país, de modo a refletir as evidências científicas disponíveis. Sua construção fundamentou-se na articulação e contribuição estratégica de especialistas brasileiros com conhecimento, experiência e atualização sobre diferentes aspectos da doença. Representa o resultado da estreita colaboração entre a Sociedade Brasileira de Medicina Tropical e o Ministério da Saúde. Espera-se com este documento fortalecer o desenvolvimento de ações integradas para enfrentamento da doença no país com foco em epidemiologia, gestão, atenção integral (incluindo famílias e comunidades), comunicação, informação, educação e pesquisas.

Up to now, no vaccines are available for Chagas disease, and the current therapy is largely unsatisfactory. Novel imidazolebased scaffolds of protozoan sterol 14α-demethylase (CYP51) inhibitors have demonstrated potent antiparasitic activity with no acute toxicity. Presently our aim was to investigate the effectiveness of the experimental 14α-demethylase inhibitor VFV in the mouse models of Trypanosoma cruzi infection using a naturally drug-resistant Colombiana strain, under monotherapy and in association with the reference drug, benznidazole (Bz). The treatment with VFV resulted in complete parasitemia suppression and 100% animal survival when administered orally (given in 10% DMSO plus 5% Arabic gum) at 25 mg/kg (bid) for 60 days. However, as parasite relapse was found using VFV alone under this treatment scheme, the coadministration of VFV with Bz was assayed giving simultaneously (for 60 days, bid) by oral route, under two different drug vehicles (10% DMSO plus 5% Gum Arabic with or without 3% Tween 80). All tested mice groups resulted in >99.9% of parasitemia decrease and 100% animal survival. qPCR analysis performed on cyclophosphamide immunosuppressed mice revealed that, although presenting lack of cure, VFV given as monotherapy was 14-fold more active than Bz, and the coadministration of Bz plus VFV (given simultaneously, using 10% DMSO plus 5% Gum Arabic as vehicle) resulted in 106-fold lower blood parasitism as compared to the monotherapy of Bz. Another interesting finding was the parasitological cure in 70% of the animals treated with Bz and VFV when the coadministration was given using the VFV suspension in 10% DMSO + Arabic gum + Tween 80 (a formulation that we have found to provide a better pharmacokinetics), even after immunosuppression using cyclophosphamide cycles, supporting the promising aspect of the drug coadministration in improving the efficacy of therapeutic arsenal against T. cruzi.

Background The specific roles of parasite characteristics and immunological factors of the host in Chagas disease progression and prognosis are still under debate. Trypanosoma cruzi genotype may be an important determinant of the clinical chronic Chagas disease form and prognosis. This study aimed to identify the potential association between T. cruzi genotypes and the clinical presentations of chronic Chagas disease. Methodology/principal findings This is a retrospective study using T. cruzi isolated from blood culture samples of 43 patients with chronic Chagas disease. From 43 patients, 42 were born in Brazil, mainly in Southeast and Northeast Brazilian regions, and one patient was born in Bolivia. Their mean age at the time of blood collection was 52.4±13.2 years. The clinical presentation was as follows 51.1% cardiac form, 25.6% indeterminate form, and 23.3% cardiodigestive form. Discrete typing unit (DTU) was determined by multilocus conventional PCR. TcII (n = 40) and TcVI (n = 2) were the DTUs identified. DTU was unidentifiable in one patient. The average follow-up time after blood culture was 5.7±4.4 years. A total of 14 patients (32.5%) died and one patient underwent heart transplantation. The cause of death was sudden cardiac arrest in six patients, heart failure in five patients, not related to Chagas disease in one patient, and ignored in two patients. A total of 8 patients (18.6%) progressed, all of them within the cardiac or cardiodigestive forms. Conclusions/significance TcII was the main T. cruzi DTU identified in chronic Chagas disease Brazilian patients (92.9%) with either cardiac, indeterminate or cardiodigestive forms, born at Southeast and Northeast regions. Other DTU found in much less frequency was TcVI (4.8%). TcII was also associated to patients that evolved with heart failure or sudden cardiac arrest, the two most common and ominous consequences of the cardiac form of Chagas disease.

BACKGROUND Calpains are present in almost all organisms and comprise a family of calcium-dependent cysteine peptidases implicated in crucial cellular functions. Trypanosoma cruzi, the causative agent of Chagas disease, presents an expansion on this gene family with unexplored biological properties. OBJECTIVES Here, we searched for calpains in the T. cruzi genome, evaluated the mRNA levels, calpain activity and the protein expression and determined the cellular localisation in all three parasite life cycle forms. METHODS/FINDINGS Sixty-three calpain sequences were identified in T. cruzi CL Brener genome, with fourteen domain arrangements. The comparison of calpain mRNA abundance by quantitative polymerase chain reaction (qPCR) revealed seven up-regulated sequences in amastigotes and/or bloodstream trypomastigotes and five in epimastigotes. Western Blotting analysis revealed seven different molecules in the three parasite forms, and one amastigote-specific, while no proteolytic activity could be detected. Flow cytometry assays revealed a higher amount of intracellular calpains in amastigotes and/or trypomastigotes in comparison to epimastigotes. Finally, ultrastructural analysis revealed the presence of calpains in the cytoplasm, vesicular and plasma membranes of the three parasite forms, and in the paraflagellar rod in trypomastigotes. CONCLUSION Calpains are differentially expressed and localised in the T. cruzi life cycle forms. This study adds data on the calpain occurrence and expression pattern in T. cruzi.