Correlation of TcII discrete typing units with severe chronic Chagas cardiomyopathy in patients from various Brazilian geographic regions

Cardiac involvement in Chagas disease and African trypanosomiasis

Trypanosomiases are diseases caused by various species of protozoan parasite in the genus Trypanosoma, each presenting with distinct clinical manifestations and prognoses. Infections can affect multiple organs, with Trypanosoma cruzi predominantly affecting the heart and digestive system, leading to American trypanosomiasis or Chagas disease, and Trypanosoma brucei primarily causing a disease of the central nervous system known as human African trypanosomiasis or sleeping sickness. In this Review, we discuss the effects of these infections on the heart, with particular emphasis on Chagas disease, which continues to be a leading cause of cardiomyopathy in Latin America. The epidemiology of Chagas disease has changed substantially since 1990 owing to the emigration of over 30 million Latin American citizens, primarily to Europe and the USA. This movement of people has led to the global dissemination of individuals infected with T. cruzi. Therefore, cardiologists worldwide must familiarize themselves with Chagas disease and the severe, chronic manifestation - Chagas cardiomyopathy - because of the expanded prevalence of this disease beyond traditional endemic regions.

Exploring the latency period in Chagas disease: duration and determinants in a cohort from Colombia

BACKGROUND

Chagas disease has a varying latency period, the time between infection and onset of cardiac symptoms, due to multiple factors. This study seeks to identify and understand these factors to enhance our knowledge of the disease.

METHODS

A retrospective follow-up study was conducted in Colombia on patients with indeterminate chronic Chagas disease. Medical files were examined to evaluate the disease latency time using time ratios (TRs) and the AFT Weibull model.

RESULTS

The study followed 578 patients, of whom 309 (53.5%) developed cardiac disease, with a median latency period of 18.5 (95% CI 16 to 20) y for the cohort. Those with the TcISyl genotype (TR 0.72; 95% CI 0.61 to 0.80), individuals who lived 5-15 y (TR 0.80; 95% CI 0.67 to 0.95), 15-30 y (TR 0.63; 95% CI 0.53 to 0.74) or >30 y (vs 5 y) in areas with high disease prevalence had shorter latency periods. On the other hand, undergoing treatment increased the latency period (TR: 1.74; 95% CI 1.52 to 1.87).

CONCLUSIONS

The latency period of Chagas disease was found to be independently related to male gender, receipt of etiological treatment, length of time spent in an endemic area and the TcISyl genotype. The implications of these findings are discussed.

Fifteen Years after the Definition of Trypanosoma cruzi DTUs: What Have We Learned?

Trypanosoma cruzi, the protozoan causative of Chagas disease (ChD), exhibits striking genetic and phenotypic intraspecific diversity, along with ecoepidemiological complexity. Human-pathogen interactions lead to distinct clinical presentations of ChD. In 2009, an international consensus classified T. cruzi strains into six discrete typing units (DTUs), TcI to TcVI, later including TcBat, and proposed reproducible genotyping schemes for DTU identification. This article aims to review the impact of classifying T. cruzi strains into DTUs on our understanding of biological, ecoepidemiological, and pathogenic aspects of T. cruzi. We will explore the likely origin of DTUs and the intrinsic characteristics of each group of strains concerning genome organization, genomics, and susceptibility to drugs used in ChD treatment. We will also provide an overview of the association of DTUs with mammalian reservoirs, and summarize the geographic distribution, and the clinical implications, of prevalent specific DTUs in ChD patients. Throughout this review, we will emphasize the crucial roles of both parasite and human genetics in defining ChD pathogenesis and chemotherapy outcome.