Drug screening and development cascade for Chagas disease: an update of in vitro and in vivo experimental models.

Chagas disease is a tropical neglected disease that affects millions of people worldwide, still demanding a more effective and safer therapy, especially in its chronic phase which lacks a treatment that promotes substantial parasitological cure. The technical note of Romanha and collaborators published in 2010 aimed establish a guideline with the set of minimum criteria and decision gates for the development of new agents against Trypanosoma cruzi with the focus on developing new antichagasic drugs. In this sense, the present review aims to update this technical note, bringing the state of the art and new advances on this topic in recent years.

Omega-3 supplementation on inflammatory markers in patients with chronic Chagas cardiomyopathy: a randomized clinical study.

BACKGROUND: Several studies have been focusing on the effect of omega-3 polyunsaturated fatty acids on modulation of inflammatory markers in several cardiopathies. Although immunoregulatory dysfunction has been associated to the chronic cardiac involvement in Chagas disease, there is no study examining the effects of omega-3 supplementation in these patients. We investigated the effects of omega-3 PUFAs on markers of inflammation and lipid profile in chronic Chagas cardiomyopathy patients. METHODS: The present study was a single-center double-blind clinical trial including patients with chronic Chagas cardiomyopathy. Patients were randomly assigned to receive omega-3 PUFAs capsules (1.8g EPA and 1.2g DHA) or placebo (corn oil) during an 8-week period. Cytokines, fasting glucose, lipid, and anthropometric profiles were evaluated. RESULTS: Forty-two patients (23 women and 19 men) were included in the study and there were only two losses to follow-up during the 8-week period. Most of sociodemographic and clinical characteristics were similar between the groups at baseline, except for the cytokines IL-1ß, IL-6, IL-8, IL-10, IL-17α, and IFNγ. The omega-3 PUFAs group demonstrated greater improvements in serum triglycerides (-21.1 vs. -4.1; p = 0.05) and IL-10 levels (-10.6 vs. -35.7; p = 0.01) in comparison to controls after 8 weeks of intervention. No further differences were observed between groups. CONCLUSION: Omega-3 PUFAs supplementation may favorably affect lipid and inflammatory profile in chronic Chagas cardiomyopathy patients, demonstrated by a decrease in triglycerides and improvements on IL-10 concentration. Further studies examining the clinical effects of omega-3 fatty acids supplementation in chronic Chagas cardiomyopathy are necessary. TRIAL REGISTRATION: NCT01863576.

Morbidity of Chagas heart disease in the microregion of Rio Negro, Amazonian Brazil: a case-control study.

A case-control study on the morbidity of Chagas heart disease was carried out in the municipality of Barcelos in the microregion of the Rio Negro, state of Amazonas. One hundred and six individuals, who were serologically positive for Trypanosoma cruzi infection, as confirmed by at least two techniques with different principles, were matched according to age and sex with an equal number of seronegative individuals. The cases and controls were evaluated using an epidemiological questionnaire and clinical, electrocardiograph and echocardiograph examinations. In the seroepidemiological evaluation, 62% of the interviewees recognised triatomines and most of them confirmed that they had seen these insects in the piassava plantations of the riverside communities of the Negro River tributaries. Of the seropositive patients, 25.8% affirmed that they had been stung by the triatomines and 11.7% denied having been stung. The principal clinical manifestations of the seropositive individuals were palpitations, chest pain and dyspnoea upon effort. Cardiac auscultation revealed extrasystoles, bradycardia and systolic murmurs. The electrocardiographic alterations were ventricular extrasystoles, left and right bundle branch block, atrioventricular block and primary T wave alterations. The echocardiogram was altered in 22.6% of the seropositive individuals and in 8.5% of the seronegative individuals.

Exploring the Historical Background and Clinical Implications of Electrocardiogram in the Context of Chagas Disease Research.

Chagas disease (CD) remains one of the most significant endemic diseases in Latin America. Approximately 30% of individuals with CD develop the cardiac form, the main determinant of morbidity and mortality, which is characterized by typical electrocardiogram (ECG) changes caused by chronic chagasic cardiopathy (CCC). This review accentuates to how crucial it is for research teams and reference centers that treat patients with CD to standardize ECG in CCC. This was a non-systematic review of the literature. ECG is the most widely used examination in the diagnosis and evaluation of CCC, and it is also employed in epidemiological surveys, risk stratification for cardiovascular events and death, and monitoring the clinical progression of the disease. Carlos Chagas and Eurico Villela published the first work addressing CCC in 1922. Other works followed, including the study by Evandro Chagas' which was the first to perform ECG in CD, culminating in Francisco Laranja's seminal work in 1956. Since the 1980s, standardizations and ECG reading codes for CD have been established. This standardization aimed to code complex arrhythmias and characteristic ventricular conduction disorders and standardize ECG readings for clinical and epidemiological studies in CD. Nearly all existing electrocardiographic abnormalities can be found in CD, with a predominance of abnormalities in the formation and conduction of cardiac stimuli. The complex and heterogeneous substrate of CD with varied electrocardiographic manifestations poses a significant challenge when comparing studies involving patients with CCC, emphasizing the need for ECG standardization in CD.

Inspiratory Muscle Strength in Chagas Cardiomyopathy: A Systematic Scoping Review.

The increase in inflammatory markers associated with persistent chronic fibrosing myocarditis, a characteristic of chronic Chagas disease, can result in a reduction in inspiratory muscle strength (IMS) in Chagas cardiomyopathy (CC). However, literature in this field is still scarce. This review aimed to map and summarize the evidence regarding IMS in patients with CC. The inclusion criteria included reports with adult participants with a CC diagnosis, with or without heart failure (HF). The core concept examined was the maximum inspiratory pressure evaluated in the untrained and trained groups in the pre-training period. The context was open, including but not limited to hospitals and health centers. Two authors independently identified eligible studies and extracted the data. Descriptive synthesis was used as the primary strategy for analyzing the results. Nine studies (five clinical trials, three cross-sectional, and one cohort) were included. The CC classification differed among the studies, with no mention of HF in five and no CC staging specification in six. IMS was assessed using a manovacuometer, and only six studies analyzed and interpreted the data concerning the predicted values. The CC population with HF appeared to have impaired IMS. All studies involved only Brazilian volunteers. In conclusion, randomized clinical trials evaluating IMS and the effects of inspiratory muscle training need to be conducted to better understand the prevalence and risk of inspiratory muscle weakness in the CC population, as well as the effects of training. Such studies should be conducted at different stages of CC in different populations and countries.

Correction: Clinical profile and mortality in patients with T. cruzi/HIV co-infection from the multicenter data base of the "Network for healthcare and study of Trypanosoma cruzi/HIV co-infection and other immunosuppression conditions".

[This corrects the article DOI: 10.1371/journal.pntd.0009809.].

The CUIDA Chagas Project: towards the elimination of congenital transmission of Chagas disease in Bolivia, Brazil, Colombia, and Paraguay.

BACKGROUND: Mother-to-child transmission of Chagas disease (CD) has become a relevant problem in both endemic and non-endemic areas. METHODS: Description of the CUIDA Chagas Project - Communities United for Innovation, Development and Attention for Chagas disease'. RESULTS: Through innovative and strategic research, this project will provide improved diagnostic and treatment options as well as replicable implementation models that are adaptable to different contexts. CONCLUSIONS: By integrating test, treat and care actions for CD into primary health care practices, the burden of CD on people and health systems may be significantly reduced.

Chagas disease mortality during the coronavirus disease 2019 pandemic: A Brazilian referral center experience.

BACKGROUND: We investigated the mortality rates of patients with Chagas disease (CD) during the coronavirus disease 2019 (COVID-19) pandemic and assessed the association between this mortality and CD clinical presentation and comorbidities. METHODS: This was an observational retrospective study with clinical data retrieved from medical records. RESULTS: Comorbidities were more prevalent among patients who died from COVID-19 than those who died from other causes. The proportion of patients according to CD clinical presentation was similar between the two groups. CONCLUSIONS: The prevalence of comorbidities seems to be related to a poorer prognosis in CD and COVID-19.

Epidemiological-clinical profile and mortality in patients coinfected with Trypanosoma cruzi/HIV: experience from a Brazilian reference center.

BACKGROUND: The recent urbanization of Chagas disease (CD) has contributed to a greater risk of coexistence with human immunodeficiency virus (HIV) and AIDS. METHODS: This retrospective observational study included patients who were followed at INI-Fiocruz between July 1986 and October 2021. All patients underwent an assessment protocol that included sociodemographic profile, epidemiological history, and clinical evaluation. Descriptive data analyses included reports of the medians and frequencies of variables of interest. Differences in medians between groups were tested using the Mann-Whitney U test. Differences in frequency were tested using Fisher's exact test. RESULTS: Among 2201 patients, 11 (0.5%) were identified with Trypanosoma cruzi/HIV coinfection. Of these, 63.6% were women with a median age of 51.0 years old. Two patients had the indeterminate form of CD, six had the cardiac form, two had the digestive form and one had the cardio-digestive form. Half of the patients were undergoing antiretroviral treatment at the time of coinfection diagnosis with a median CD4+ count of 350 cells/µL and a viral load of 1500 copies/µL. Four patients underwent a xenodiagnosis test at coinfection diagnosis, which all yielded positive results; two of them presented high parasitemia under the risk of reactivation. Prophylaxis for CD reactivation was administered to four patients; two with ketoconazole and two with benznidazole. Six patients died after a median follow-up of 22.5 months, with AIDS being the most common cause of death. Only one case of reactivation was observed. CONCLUSIONS: Early diagnosis and prompt treatment of CD reactivation dramatically reduced mortality. Identification of Trypanosoma cruzi/HIV co-infection is crucial to planning a close follow-up of coinfected patients.

The association between variables of cardiopulmonary exercise test and quality of life in patients with chronic Chagas cardiomyopathy (Insights from the PEACH STUDY).

Studies investigating the association between functional capacity and quality of life (QoL) in individuals with chronic Chagas cardiomyopathy (CCC) usually do not include a gold-standard evaluation of functional capacity, limiting the validity and the interpretation of the results. The present study is a cross-section analysis aiming to evaluate the association between functional capacity (quantified by cardiopulmonary exercise test [CPET]) and QoL in individuals with CCC. QoL was assessed using the SF-36 questionnaire. Sociodemographic, anthropometric, clinical, cardiac function and maximal progressive CPET variables were obtained from PEACH study. Generalized linear models adjusted for age, sex, and left ventricular ejection fraction were performed to evaluate the association between CPET variables and QoL. After adjustments, VO2 peak and VO2 AT were both associated with physical functioning (ß = +0.05 and ß = +0.05, respectively) and physical component summary (ß = +0.03 and ß = +0.03, respectively). Double product was associated with physical functioning (ß = +0.003), general health perceptions (ß = +0.003), physical component summary (ß = +0.002), and vitality (ß = +0.004). HRR≤12bpm was associated with physical functioning (ß = -0.32), role limitations due to physical problems (ß = -0.87), bodily pain (ß = -0.26), physical component summary (ß = -0.21), vitality (ß = -0.38), and mental health (ß = -0.19). VE/VCO2 slope presented association with all mental scales of SF-36: vitality (ß = -0.028), social functioning (ß = -0.024), role limitations due to emotional problems (ß = -0.06), mental health (ß = -0.04), and mental component summary (ß = -0.02). The associations between CPET variables and QoL demonstrate the importance of CPET inclusion for a more comprehensive evaluation of individuals with CCC. In this setting, intervention strategies aiming to improve functional capacity may also promote additional benefits on QoL and should be incorporated as a treatment strategy for patients with CCC.

Indeterminate form of Chagas disease: historical, conceptual, clinical, and prognostic aspects.

Chagas disease (CD) remains a serious endemic disease in Latin America and a major public health problem. Because of globalization, the disease has spread to non-endemic areas in the northern hemisphere. In the chronic phase of the disease, most patients present with the indeterminate form (IF), characterized by positive serology for Trypanosoma cruzi, absence of clinical findings, and normal findings in electrocardiogram (ECG). IF was not recognized as a clinical entity until decades after the discovery of the disease, and only in the 1940-50s, it was categorized as a form of CD, and its conceptual definition was ratified in the 1980s. Children, adolescents, and young adults with the IF benefit from etiological treatment and tend to have less progression to heart disease in the long term than the untreated ones. IF patients have an essentially benign clinical condition, and their prognosis can be compared to that of healthy individuals with normal ECG findings. Currently, because of aging, patients with the IF have comorbidities that require attention in health services.

Temporal changes in the clinical-epidemiological profile of patients with Chagas disease at a referral center in Brazil.

INTRODUCTION: We aimed to describe the sociodemographic, epidemiological, and clinical characteristics of patients with chronic Chagas disease (CD) at an infectious disease referral center. Changes in patient profiles over time were also evaluated. METHODS: This retrospective study included patients with CD from November 1986-December 2019. All patients underwent an evaluation protocol that included sociodemographic profile; epidemiological history; anamnesis; and physical, cardiologic, and digestive examinations. Trend differences for each 5-year period from 1986 to 2019 were tested using a nonparametric trend test for continuous and generalized linear models with binomial distribution for categorical variables. RESULTS: A total of 2,168 patients (52.2% women) were included, with a mean age of 47.8 years old. White patients with low levels of education predominated. The reported transmission mode was vectorial in 90.2% of cases. The majority came from areas with a high prevalence (52.2%) and morbidity (67.8%) of CD. The most common clinical presentation was the indeterminate form (44.9%). The number of patients referred gradually decreased and the age at admission increased during the study period, as did the patients' levels of education. CONCLUSIONS: The clinical profile of CD is characterized by a predominance of the indeterminate form of the disease. Regarding the patients who were followed up at the referral center, there was a progressive increase in the mean age and a concomitant decrease in the number of new patients. This reflects the successful control of vector and transfusion transmission in Brazil as well as the aging population of patients with CD.

Clinical profile and mortality in patients with T. cruzi/HIV co-infection from the multicenter data base of the "Network for healthcare and study of Trypanosoma cruzi/HIV co-infection and other immunosuppression conditions".

OBJECTIVE: Chagas disease (CD) globalization facilitated the co-infection with Human Immunodeficiency Virus (HIV) in endemic and non-endemic areas. Considering the underestimation of Trypanosoma cruzi (T. cruzi)-HIV co-infection and the risk of life-threatening Chagas Disease Reactivation (CDR), this study aimed to analyze the major co-infection clinical characteristics and its mortality rates. METHODS: This is a cross-sectional retrospective multicenter study of patients with CD confirmed by two serological or one parasitological tests, and HIV infection confirmed by immunoblot. CDR was diagnosed by direct microscopy with detection of trypomastigote forms in the blood or other biological fluids and/or amastigote forms in inflammatory lesions. RESULTS: Out of 241 patients with co-infection, 86.7% were from Brazil, 47.5% had <200 CD4+ T cells/µL and median viral load was 17,000 copies/µL. Sixty CDR cases were observed. Death was more frequent in patients with reactivation and was mainly caused by CDR. Other causes of death unrelated to CDR were the manifestation of opportunistic infections in those with Acquired Immunodeficiency Syndrome. The time between the co-infection diagnosis to death was shorter in patients with CDR. Lower CD4+ cells count at co-infection diagnosis was independently associated with reactivation. Similarly, lower CD4+ cells numbers at co-infection diagnosis and male sex were associated with higher lethality in CDR. Additionally, CD4+ cells were lower in meningoencephalitis than in myocarditis and milder forms. CONCLUSION: This study showed major features on T. cruzi-HIV co-infection and highlighted the prognostic role of CD4+ cells for reactivation and mortality. Since lethality was high in meningoencephalitis and all untreated patients died shortly after the diagnosis, early diagnosis, immediate antiparasitic treatment, patient follow-up and epidemiological surveillance are essentials in T. cruzi/HIV co-infection and CDR managements.

Associations between Cardiac Magnetic Resonance T1 Mapping Parameters and Ventricular Arrhythmia in Patients with Chagas Disease.

Chronic Chagas disease can progress to myocardial involvement with intense fibrosis, which may predispose patients to sudden cardiac death through ventricular arrhythmia. The associations of myocardial fibrosis detected by cardiac magnetic resonance (CMR) parameters with non-sustained ventricular tachycardia (NSVT) were evaluated. This cross-sectional study included patients in early stages of Chagas disease (n = 47) and a control group (n = 15). Patients underwent cardiac evaluation, including CMR examination. Myocardial fibrosis assessment by CMR with measurement of late gadolinium enhancement (LGE), native T1, and extracellular volume (ECV) was performed. There was an increase in myocardial fibrosis CMR parameters and ventricular arrhythmias among different stages of Chagas disease, combined with a decrease in the left ventricular ejection fraction (LVEF) by CMR and also in the right ventricular systolic function by S' wave on tissue Doppler. Fibrosis mass and ECV were associated with the Rassi score, ventricular extrasystole, and E/e' ratio in a logistic regression model adjusted for age and gender. The ECV maintained an association with the presence of NSVT, even after adjustments for fibrosis mass and LVEF assessed by CMR. The receiver-operating characteristic area under the curve for global ECV (0.85; 95% CI: 0.71-0.99) and NSVT was greater than that for fibrosis mass (0.75; 95% CI: 0.54-0.96), although this difference was not statistically significant. Extracellular volume could be an early marker of increased risk of ventricular arrhythmia in Chagas disease, presenting an independent association with NSVT in the initial stages of chronic Chagas cardiomyopathy, even after adjustment for fibrosis mass and LVEF.

Adverse drug events and the associated factors in patients with chronic Chagas disease.

INTRODUCTION: Herein, we aimed to identify the factors associated with adverse drug events (ADEs) in chronic Chagas disease (CD) patients. METHODS: We analyzed 320 medical notes from 295 patients. The Naranjo algorithm was applied to determine the cause of ADEs. Mixed effects logistic regression was performed to evaluate the factors associated with ADEs. RESULTS: ADEs were described in 102 medical notes (31.9%). Captopril was most frequently associated with ADEs. Age (RR 0.96; 95%CI 0.94-0.99) and cardiac C/D stages (RR 3.24; 95%CI 1.30-4.58) were the most important clinical factors associated with ADEs. CONCLUSIONS: Close follow-up is warranted for CD patients.

Progression Rate from the Indeterminate Form to the Cardiac Form in Patients with Chronic Chagas Disease: Twenty-Two-Year Follow-Up in a Brazilian Urban Cohort.

Most patients with chronic Chagas disease (CD) present the indeterminate form and are at risk to develop the cardiac form. However, the actual rate of progression to the cardiac form is still unknown. METHODS: In total, 550 patients with the indeterminate CD form were followed by means of annual electrocardiogram at our outpatient clinic. The studied endpoint was progression to cardiac form defined by the appearance of electrocardiographic changes typical of CD. The progression rate was calculated as the cumulative progression rate and the incidence progression rate per 100 patient years. RESULTS: Thirty-seven patients progressed to the CD cardiac form within a mean of 73 ± 4 8 months of follow-up, which resulted in a 6.9% cumulative progression rate and incidence rate of 1.48 cases/100 patient years. Patients who progressed were older (mean age 47.8 ± 12.2 years), had a higher prevalence of associated heart diseases (p < 0.0001), positive xenodiagnosis (p = 0.007), and were born in the most endemic Brazilian states (p = 0.018). Previous co-morbidities remained the only variable associated with CD progression after multivariate Cox proportional hazards regression analysis (p = 0.002). CONCLUSION: The progression rate to chronic CD cardiac form is low and inferior to rates previously reported in other studies.

Case Report: Malignant Ventricular Arrhythmias Mimicking Acute Coronary Syndrome in Chagas Disease.

Chronic Chagas heart disease has different clinical manifestations including arrhythmias, heart failure, and stroke. Chest pain is one of the most common symptoms and when associated with changes in the electrocardiogram, such as T-wave changes, electrically inactive areas, and segmental wall motion abnormalities, may lead to a misdiagnosis of acute coronary syndrome (ACS). Here, we describe two patients with Chagas heart disease and syncope due to sustained ventricular tachycardia who were misdiagnosed with ACS, and discuss the role of novel imaging modalities in the differential diagnosis and risk stratification.

Agreement between upper endoscopy and esophagography in the diagnosis of megaesophagus in Chagas disease.

INTRODUCTION: The diagnosis and classification of megaesophagus can be challenging in patients with Chagas disease. The present study aimed to evaluate the agreement between upper endoscopies and esophagographies for the diagnosis and classification of megaesophagus in Chagas disease. METHODS: A cross-sectional study of 50 patients with Chagas disease with upper digestive symptoms was undertaken. Esophagography and upper endoscopy exams were performed to compare diagnoses. Statistical analysis included sensitivity and specificity used to evaluate the diagnostic accuracy of upper endoscopies, and measures of agreement: linearly weighted Kappa (κw) and Cohen`s classical Kappa (κ) coefficients with 95% confidence intervals (95% CI). RESULTS: Twenty-three patients (46%) were diagnosed with megaesophagus by esophagography. The upper endoscopy sensitivity and specificity for megaesophagus diagnosis were 100% and 33.3%, respectively. Regarding megaesophagus classifications, there was a substantial agreement between the two exams (κw = 0.622; 95% CI: 0.498 to 0.746). Within megaesophagus groups, agreement for group I was slight (κ = 0.096; 95% CI: 0.000 to 0.403); for group II, substantial (κ = 0.703; 95% CI: 0.456 to 0.950); and for groups III and IV, inconclusive (κ = 0.457; 95% CI: 0.000 to 0.967; κ = 0.540; 95% CI: 0.035 to 1.000, respectively). CONCLUSIONS: Upper endoscopy has a high sensitivity, but a low specificity to diagnose megaesophagus. Agreement between the two exams varies depending on the megaesophagus grade. Thus, upper endoscopy can be used in the diagnostic workup of a possible Chagas disease megaesophagus, but all identified cases should undergo esophagography.

Exploring the Historical Background and Clinical Implications of Electrocardiogram in the Context of Chagas Disease Research

ABSTRACT Chagas disease (CD) remains one of the most significant endemic diseases in Latin America. Approximately 30% of individuals with CD develop the cardiac form, the main determinant of morbidity and mortality, which is characterized by typical electrocardiogram (ECG) changes caused by chronic chagasic cardiopathy (CCC). This review accentuates to how crucial it is for research teams and reference centers that treat patients with CD to standardize ECG in CCC. This was a non-systematic review of the literature. ECG is the most widely used examination in the diagnosis and evaluation of CCC, and it is also employed in epidemiological surveys, risk stratification for cardiovascular events and death, and monitoring the clinical progression of the disease. Carlos Chagas and Eurico Villela published the first work addressing CCC in 1922. Other works followed, including the study by Evandro Chagas' which was the first to perform ECG in CD, culminating in Francisco Laranja's seminal work in 1956. Since the 1980s, standardizations and ECG reading codes for CD have been established. This standardization aimed to code complex arrhythmias and characteristic ventricular conduction disorders and standardize ECG readings for clinical and epidemiological studies in CD. Nearly all existing electrocardiographic abnormalities can be found in CD, with a predominance of abnormalities in the formation and conduction of cardiac stimuli. The complex and heterogeneous substrate of CD with varied electrocardiographic manifestations poses a significant challenge when comparing studies involving patients with CCC, emphasizing the need for ECG standardization in CD.