Chronic Chagas Disease-the Potential Role of Reinfections in Cardiomyopathy Pathogenesis

Impact of antiparasitic therapy on cardiovascular outcomes in chronic Chagas disease. A systematic review and meta-analysis

Background

Endemic in more than 20 countries, Chagas disease affects 6.3 million people worldwide, leading to 28,000 new infections and 7700 deaths each year. Previous meta-analyses on antiparasitic treatment need updates to encompass recent studies and to assess key clinically meaningful endpoints. This study aims to evaluate the impact of antitrypanosomal therapy in preventing or reducing disease progression and mortality in chronic Chagas disease.

Methods

We performed a systematic review and meta-analysis of studies reporting the cardiovascular outcomes of antitrypanosomal therapy in patients with chronic Chagas disease. We searched Ovid Embase, Ovid MEDLINE, Ovid Global Health, Scopus, Web of Science Core Collection, Cochrane Library, PubMed, Google Scholar, and Virtual Health Library databases from inception to May 18, 2024. We included aggregated data from randomized controlled studies and observational reports (full articles and abstracts) featuring antiparasitic interventions with benznidazole or nifurtimox compared to a control group. Primary outcomes were electrocardiogram (ECG) changes, disease progression, cardiovascular death, and overall mortality. A customized risk of bias scale assessed the methodological quality of studies, and a random-effects model estimated the pooled risk ratios. This investigation was registered in PROSPERO (CRD42023495755).

Findings

Out of 4666 reports screened, 23 met the pre-specified inclusion criteria (8972 participants). Compared to no treatment or placebo, antiparasitic treatment led to a reduction in i) ECG changes (17 studies, 4994 participants: risk ratio (RR): 0.48, 95% CI 0.36-0.66, p < 0.001; I 2 = 76.4%) with a number needed to treat (NNT) of 5; ii) disease progression (12 studies, 5722 participants: RR: 0.35, 95% CI 0.23-0.51, p < 0.001; I 2 = 72.4%) NNT of 6; iii) cardiovascular death (7 studies, 5662 participants: RR: 0.44, 95% CI 0.21-0.95, p = 0.04; I 2 = 50.5%) NNT of 22; and iv) overall mortality (10 studies, 7694 participants: RR: 0.54, 95% CI 0.34-0.87, p < 0.001; I 2 = 60%) NNT of 23.

Interpretation

We found compelling evidence that antiparasitic treatment significantly reduces the risk of ECG changes, disease progression, cardiovascular death, and overall mortality in chronic Chagas disease. Although the quality of evidence ranges from low to intermediate, with considerable heterogeneity across studies, the potential benefits are substantial. These findings support the broader use of trypanocidal therapy in the management of Chagas disease, though further research remains necessary.

Funding

This study had no funding source.

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.

Tackling the challenges of human Chagas disease: A comprehensive review of treatment strategies in the chronic phase and emerging therapeutic approaches

Chagas disease (CD), caused by the flagellated protozoan Trypanosoma cruzi (T. cruzi), affects approximately 7 million people worldwide and is endemic in Latin America, especially among socioeconomically disadvantaged populations. Since the 1960s, only two drugs have been commercially available for treating this illness: nifurtimox (NFX) and benznidazole (BZN). Although these drugs are effective in the acute phase (AP) of the disease, in which parasitemia is usually high, their cure rates in the chronic phase (CP) are low and often associated with several side effects. The CP is characterized by a subpatent parasitaemia and absence of clinical symptoms in the great majority of infected individuals. However, at least 30 % of the individuals will develop potentially lethal symptomatic forms, including cardiac and digestive manifestations. For such reason, in the CP the treatment is usually symptomatic and typically focuses on managing complications such as arrhythmias, heart failure, or digestive problems. Therefore, the need for new drugs or therapeutic approaches using BZN or NFX is extremely urgent. This review presents the main clinical trials, especially in the CP, which involve BZN and NFX in different treatment regimens. Additionally, other therapies using combinations of these drugs with other substances such as allopurinol, itraconazole, ravuconazole, ketoconazole, posaconazole and amiodarone are also reported. The importance of early diagnosis, especially in pediatric patients, is also discussed, emphasizing the need to identify the disease in its early stages to improve the chances of successful treatment.

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.

Chagas disease in the United States: a call for increased investment and collaborative research

Chagas disease, caused by the protozoan Trypanosoma cruzi, is a highly overlooked parasitic infection within the United States. It affects an estimated 300,000 individuals, often remaining asymptomatic for years before triggering severe complications such as cardiomyopathy in 30-40% of cases. While many contract the disease in Latin America, its transmission by local vectors in the southern U.S. presents a significant challenge. Unfortunately, limited access to diagnosis and treatment persists, alongside unresolved gaps in healthcare systems and disease pathogenesis. In this viewpoint, we discuss the need for focused research and public health initiatives, with U.S. research institutions playing a crucial role in developing new treatments and identifying biomarkers. Furthermore, investigating the genetic variations of T. cruzi between North and South America is vital for improving diagnostic and treatment strategies. Urgent action is required to implement national and local programs, bolstering healthcare responses and advancing research efforts.Q4As per journal style section heading 'Introduction' is mandatory, hence we have introduced the heading. Please check, and correct if necessary.ResolvedQ5If there are any drug dosages in your article, please verify them and indicate that you have done so by initialing this query.ResolvedQ6Please supply the year of publication.ResolvedFootnoteView Edit Log9.

Signatures of CD4+ T and B cells are associated with distinct stages of chronic chagasic cardiomyopathy

Introduction

Chagas disease is a neglected parasitic disease caused by Trypanosoma cruzi. While most patients are asymptomatic, around 30% develop Chronic Chagasic Cardiomyopathy (CCC).

Methods

Here, we employed high-dimensional flow cytometry to analyze CD4+ T and B cell compartments in patients during the chronic phase of Chagas disease, presenting the asymptomatic and mild or moderate/severe cardiac clinical forms.

Results

Effector CD27-CD4+ T cells were expanded in both CCC groups, and only mild CCC patients showed higher frequencies of effector memory and T follicular helper (Tfh) cells than healthy donors (CTL) and asymptomatic patients. Unsupervised analysis confirmed these findings and further revealed the expansion of a specific subpopulation composed of Tfh, transitional, and central memory CD4+ T cells bearing a phenotype associated with strong activation, differentiation, and exhaustion in patients with mild but not moderate/severe CCC. In contrast, patients with mild and moderate/severe CCC had lower frequencies of CD4+ T cells expressing lower levels of activation markers, suggesting resting status, than CTL. Regarding the B cell compartment, no alterations were found in naïve CD21-, memory cells expressing IgM or IgD, marginal zone, and plasma cells in patients with Chagas disease. However, expansion of class-switched activated and atypical memory B cells was observed in all clinical forms, and more substantially in mild CCC patients.

Discussion

Taken together, our results showed that T. cruzi infection triggers changes in CD4+ T and B cell compartments that are more pronounced in the mild CCC clinical form, suggesting an orchestrated cellular communication during Chagas disease.

Conclusion

Overall, these findings reinforce the heterogeneity and complexity of the immune response in patients with chronic Chagas disease and may provide new insights into disease pathology and potential markers to guide clinical decisions.

The intersection of host in vivo metabolism and immune responses to infection with kinetoplastid and apicomplexan parasites

SUMMARYProtozoan parasite infection dramatically alters host metabolism, driven by immunological demand and parasite manipulation strategies. Immunometabolic checkpoints are often exploited by kinetoplastid and protozoan parasites to establish chronic infection, which can significantly impair host metabolic homeostasis. The recent growth of tools to analyze metabolism is expanding our understanding of these questions. Here, we review and contrast host metabolic alterations that occur in vivo during infection with Leishmania, trypanosomes, Toxoplasma, Plasmodium, and Cryptosporidium. Although genetically divergent, there are commonalities among these pathogens in terms of metabolic needs, induction of the type I immune responses required for clearance, and the potential for sustained host metabolic dysbiosis. Comparing these pathogens provides an opportunity to explore how transmission strategy, nutritional demand, and host cell and tissue tropism drive similarities and unique aspects in host response and infection outcome and to design new strategies to treat disease.

Trypanosoma cruzi Central Nervous System Infection-Pathogenesis, Clinical Manifestations, Diagnosis, and Treatment

Purpose of Review

Chagas disease (CD) is a neglected tropical disease from the American continent that commonly causes cardiovascular disease. Some patients develop neurological manifestations. We discuss and summarize the pathogenesis, clinical characteristics, diagnosis, and treatment of the central nervous system manifestations of CD.

Recent Findings

Cerebrospinal fluid quantitative polymerase chain reaction tests and next-generation sequencing in tissue samples have facilitated disease diagnosis and follow-up. Novel presentations, including retinitis, are now reported. A new MRI sign called "Bunch of açai berries appearance"-multiple hypointense nodular lesions-has been described recently. Treatment with benznidazole at higher doses and the role of therapeutic drug monitoring need to be further studied in this setting.

Summary

A high suspicion index is paramount to diagnosing Chagas' central nervous system involvement. Standardized molecular diagnostics can aid in the initial workup. Future development of new therapeutic drugs is crucial because of the toxicity profile of the currently available medications.