Fase aguda da doença de Chagas na Amazônia brasileira: estudo de 233 casos do Pará, Amapá e Maranhão observados entre 1988 e 2005

Impact of gastrointestinal inoculation and benznidazole treatment on infection by Trypanosoma cruzi (Y strain, DTU TcII) in Swiss mice

In Brazil, where Chagas disease is endemic, the most frequent form of transmission of the parasite is the oral route, associated with greater severity and worse response to benznidazole (BZ), the drug used in its treatment. This study aimed to evaluate the impact of gastrointestinal infection (GI) and BZ treatment on the parasitological and histopathological parameters in mice inoculated with a strain of T. cruzi II. Swiss mice were inoculated by GI and intraperitoneal (IP) routes with 2x106 culture-derived metacyclic trypomastigotes of the Y strain (TcII) of T. cruzi and were treated with BZ in the acute phase of the infection. Fresh blood examination, qPCR, histopathological and biochemical evaluations (enzymatic dosages and oxidative stress-OS) were performed. BZ treatment of uninfected animals caused changes in the liver, increased the activity of aspartate aminotransferase and alanine aminotransferase enzymes and OS, showing that the drug alone affects this organ. Inflammation and necrosis in the cardiac tissue were less intense and deaths occurred later in animals inoculated via the GI route than the animals inoculated via the IP route. BZ reduced the intensity of tissue lesions and avoided lethality in animals inoculated via the GI route, and decreased parasitemia and OS in those inoculated via both routes. Although BZ alone caused liver damage, it was less intense than that caused by both routes of inoculation. Infection with the Y strain of T. cruzi II via the GI route proved to be less virulent and pathogenic and responded better to treatment than the infection acquired via the IP route.

Beyond the acute phase: a comprehensive literature review of long-term sequelae resulting from infectious diseases

Infectious diseases have consistently served as pivotal influences on numerous civilizations, inducing morbidity, mortality, and consequently redirecting the course of history. Their impact extends far beyond the acute phase, characterized by the majority of symptom presentations, to a multitude of adverse events and sequelae that follow viral, parasitic, fungal, or bacterial infections. In this context, myriad sequelae related to various infectious diseases have been identified, spanning short to long-term durations. Although these sequelae are known to affect thousands of individuals individually, a comprehensive evaluation of all potential long-term effects of infectious diseases has yet to be undertaken. We present a comprehensive literature review delineating the primary sequelae attributable to major infectious diseases, categorized by systems, symptoms, and duration. This compilation serves as a crucial resource, illuminating the long-term ramifications of infectious diseases for healthcare professionals worldwide. Moreover, this review highlights the substantial burden that these sequelae impose on global health and economies, a facet often overshadowed by the predominant focus on the acute phase. Patients are frequently discharged following the resolution of the acute phase, with minimal long-term follow-up to comprehend and address potential sequelae. This emphasizes the pressing need for sustained vigilance, thorough patient monitoring, strategic health management, and rigorous research to understand and mitigate the lasting economic and health impacts of infectious diseases more fully.

Acute Chagas Disease Outbreak among Military Personnel, Colombia, 2021

We report an acute Chagas disease outbreak among soldiers in Colombia. Trypanosoma cruzi infection was confirmed through parasitology, serology, and molecular methods. Among 9 affected soldiers, 2 died; 7 were hospitalized and received benznidazole treatment, which produced favorable outcomes. Personnel patrolling rural areas in Colombia could be at increased risk for Chagas disease.

Outbreak of Chagas disease in Brazil: Validation of a molecular diagnostic method

Chagas disease (CD), caused by the protozoan Trypanosoma cruzi (T. cruzi), affects millions of people worldwide. Polymerase Chain Reaction (PCR) and real-time quantitative PCR (qPCR) have been used as tools to monitor parasitic levels in the bloodstream of individuals exposed to infection, thus enabling the monitoring of relapses and the effectiveness of therapy, for example. The aim of this study was to evaluate the TcSAT-IAM system, developed by our research group, on samples from patients with suspected Chagas disease infection. Initially, primer systems were developed for the detection of the nuclear DNA (SAT-DNA) from T. cruzi (TcSAT-IAM). The Cruzi system, predicted in the literature, and TcSAT-IAM were then evaluated in relation to their analytical sensitivity, specificity and efficiency. Afterwards, the applicability of the qPCR technique using both systems (separately) for the diagnosis of acute CD was evaluated in samples from 77 individuals exposed to the outbreak that occurred in Pernambuco-Brazil, relating the results obtained to those of the classical diagnostic methods recommended for this stage of the infection. TcSAT-IAM and Cruzi had a detection limit of 1 fg of target DNA (0,003 parasites). Thirty-eight cases were recorded, 28 by laboratory criteria and 10 by clinical and epidemiological criteria. Blood samples from 77 subjects were submitted to qPCR by both systems, reaching an agreement of 89.61% between them. After analyzes between systems and diagnostic criteria, the TcSAT-IAM showed sensitivity and specificity of 52.36% (CI 37.26-67.52) and 92.31% (CI 79.68-97.35), respectively, accuracy of 72.73% and moderate agreement. The TcSAT-IAM showed an accuracy of 72.58% and 75% in relation to parasitological and serological tests (IgM anti-T. cruzi), respectively. Therefore, quantitative PCR should be incorporated into the diagnosis of suspected acute cases of Chagas disease.

Seroprevalence of Trypanosoma cruzi in Eight Blood Banks in Mexico

BACKGROUND

The true prevalence of Chagas disease in Mexico is unknown. However, it has been estimated that 1.1-4 million people are infected with Trypanosoma cruzi, which represents a potential risk for transmission of the disease via contaminated blood.

AIM OF THE STUDY

To determine the Chagas disease seroprevalence in donors from eight blood banks in the north of Mexico City, and the northeast of the State of Mexico.

STUDY DESIGN AND METHODS

Serum samples from blood donors (n = 515,038) were tested to detect the presence of anti-Trypanosoma cruzi antibodies in eight blood banks. The serologic screening test was performed in each of the blood banks. To confirm the seropositive blood donors, only two out of the eight blood banks used a test with a different principle with the aim of identifying anti-Trypanosoma cruzi antibodies. All tests were validated by the Mexican Institute for Epidemiological Diagnosis and Reference.

RESULTS

One thousand two hundred and ten blood donors were seropositive for Trypanosoma cruzi, which represents a 0.23% seroprevalence (95% CI 0.22-0.25%). Of the seropositive blood donors, 97.03 % resided in the northeast area of the State of Mexico, Mexico City, and southern part of the State of Hidalgo.

CONCLUSIONS

Active transmission of Chagas disease may be occurring in non-endemic regions in the northeast of the State of Mexico.

Acute micro-outbreak of Chagas disease in the southeastern Amazon: a report of five cases

Background:

Chagas disease is gaining importance in the Brazilian Amazon region as a differential diagnosis of febrile syndrome. The most recent microoutbreak occurred in Ipixuna, in Amazonas state.

Methods:

An epidemiological survey was conducted using parasitological and serological tests, and electrocardiographic analysis.

Results:

The patients belonged to one family and had ingested açaí acquired from Ipixuna. All patients reported fever and initially a thick blood smear test was done to identify Trypanosoma cruzi. Benznidazole treatment was administered to all patients.

Conclusions:

Knowledge of the epidemiological dynamics of Chagas disease allows us to improve control and management measures for this disease.

Insights from the use of erythropoietin in experimental Chagas disease

In addition to the long-established role in erythropoiesis, erythropoietin (Epo) has protective functions in a variety of tissues, including the heart. This is the most affected organ in chronic Chagas disease, caused by the protozoan Trypanosoma cruzi. Despite seven million people being infected with T. cruzi worldwide, there is no effective treatment preventing the disease progression to the chronic phase when the pathological involvement of the heart is often observed. Chronic chagasic cardiomyopathy has a wide variety of manifestations, like left ventricular systolic dysfunction, dilated cardiomyopathy, and heart failure. Since Epo may help maintain cardiac function by reducing myocardial necrosis, inflammation, and fibrosis, this study aimed to evaluate whether the Epo has positive effects on experimental Chagas disease. For that, we assessed the earlier (acute phase) and also the later (chronic phase) use of Epo in infected C57BL/6 mice. Blood cell count, biochemical parameters, parasitic load, and echocardiography data were evaluated. In addition, histopathological analysis was carried out. Our data showed that Epo had no trypanocide effect nor did it modify the production of anti-T. cruzi antibodies. Epo-treated groups exhibited parasitic burden much lower in the heart compared to blood. No pattern of hematological changes was observed combining infection with treatment with Epo. Chronic Epo administration reduced CK-MB serum activity from d0 to d180, irrespectively of T. cruzi infection. Likewise, echocardiography and histological results indicate that Epo treatment is more effective in the chronic phase of experimental Chagas disease. Since treatment is one of the greatest challenges of Chagas disease, alternative therapies should be investigated, including Epo combined with benznidazole.

Chagas disease control-surveillance in the Americas: the multinational initiatives and the practical impossibility of interrupting vector-borne Trypanosoma cruzi transmission

Chagas disease (CD) still imposes a heavy burden on most Latin American countries. Vector-borne and mother-to-child transmission cause several thousand new infections per year, and at least 5 million people carry Trypanosoma cruzi. Access to diagnosis and medical care, however, is far from universal. Starting in the 1990s, CD-endemic countries and the Pan American Health Organization-World Health Organization (PAHO-WHO) launched a series of multinational initiatives for CD control-surveillance. An overview of the initiatives’ aims, achievements, and challenges reveals some key common themes that we discuss here in the context of the WHO 2030 goals for CD. Transmission of T. cruzi via blood transfusion and organ transplantation is effectively under control. T. cruzi, however, is a zoonotic pathogen with 100+ vector species widely spread across the Americas; interrupting vector-borne transmission seems therefore unfeasible. Stronger surveillance systems are, and will continue to be, needed to monitor and control CD. Prevention of vertical transmission demands boosting current efforts to screen pregnant and childbearing-aged women. Finally, integral patient care is a critical unmet need in most countries. The decades-long experience of the initiatives, in sum, hints at the practical impossibility of interrupting vector-borne T. cruzi transmission in the Americas. The concept of disease control seems to provide a more realistic description of what can in effect be achieved by 2030.

Chronic Chagas cardiomyopathy: characterization of cases and possibilities of action in primary healthcare

Despite the drastic decrease in the incidence of Chagas disease in Brazil, past cases still greatly impact health services in the country. Thus, this study aimed to characterize Chagas disease cases regarding their cardiac staging and death prognosis and, based on that, to propose primary healthcare (PHC) case follow-ups. This is a cross-sectional study based on secondary data from the medical records of patients with chronic Chagas cardiomyopathy (CCC). A logistic regression was applied to estimate crude and adjusted odds ratios (OR). A total of 433 medical records were evaluated. More severe CCC cases were associated with a greater number of hospitalizations (OR = 3.41; 95%CI: 1.59-7.30) and longer hospitalization (OR = 3.15; 95%CI: 1.79-5.53). Cases with a higher risk of death were associated with a higher number of hospitalizations (OR = 1.92; 95%CI: 1.09-3.37), longer hospital stays (OR = 2.04; 95%CI: 1.30-3.18), and visits to the outpatient clinic (OR = 2.18; 95%CI: 1.39-3.41) and the emergency department of the assessed hospital (OR = 3.12; 95%CI: 1.27-7.66). Analyzing the medical records at two moments, 72.9% of the cases remained in the stages in which they were initially evaluated. Overall, 44.4% of cases were classified as mild to moderate risk of death and 68.3% as low ones. The cases classified in the most severe stages of CCC and with high or intermediate risk of death were associated with greater hospital dependence. However, most cases were classified as milder forms of the disease, with a low risk of death and clinical stability. These findings aim to promote the role of PHC as a protagonist in the longitudinal follow-up of CCC cases in Brazil.

Prognosis of chronic Chagas heart disease and other pending clinical challenges

In this chapter, the main prognostic markers of Chagas heart disease are addressed, with an emphasis on the most recent findings and questions, establishing the basis for a broad discussion of recommendations and new approaches to managing Chagas cardiopathy. The main biological and genetic markers and the contribution of the electrocardiogram, echocardiogram and cardiac magnetic resonance are presented. We also discuss the most recent therapeutic proposals for heart failure, thromboembolism and arrhythmias, as well as current experience in heart transplantation in patients suffering from severe Chagas cardiomyopathy. The clinical and epidemiological challenges introduced by acute Chagas disease due to oral contamination are discussed. In addition, we highlight the importance of ageing and comorbidities in influencing the outcome of chronic Chagas heart disease. Finally, we discuss the importance of public policies, the vital role of funding agencies, universities, the scientific community and health professionals, and the application of new technologies in finding solutions for better management of Chagas heart disease.

The Search for Biomarkers and Treatments in Chagas Disease: Insights From TGF-Beta Studies and Immunogenetics

The anti-inflammatory cytokine transforming growth factor beta (TGF-β) plays an important role in Chagas disease (CD), a potentially life-threatening illness caused by Trypanosoma cruzi. In this review we revisited clinical studies in CD patients combined with in vitro and in vivo experiments, presenting three main sections: an overview of epidemiological, economic, and clinical aspects of CD and the need for new biomarkers and treatment; a brief panorama of TGF-β roles and its intracellular signaling pathways, and an update of what is known about TGF-β and Chagas disease. In in vitro assays, TGF-β increases during T. cruzi infection and modulates heart cells invasion by the parasite fostering its intracellular parasite cycle. TGF-β modulates host immune response and inflammation, increases heart fibrosis, stimulates remodeling, and slows heart conduction via gap junction modulation. TGF-β signaling inhibitors reverts these effects opening a promising therapeutic approach in pre-clinical studies. CD patients with higher TGF-β1 serum level show a worse clinical outcome, implicating a predictive value of serum TGF-β as a surrogate biomarker of clinical relevance. Moreover, pre-clinical studies in chronic T. cruzi infected mice proved that inhibition of TGF-β pathway improved several cardiac electric parameters, reversed the loss of connexin-43 enriched intercellular plaques, reduced fibrosis of the cardiac tissue, restored GATA-6 and Tbox-5 transcription, supporting cardiac recovery. Finally, TGF-β polymorphisms indicate that CD immunogenetics is at the base of this phenomenon. We searched in a Brazilian population five single-nucleotide polymorphisms (-800 G>A rs1800468, -509 C>T rs1800469, +10 T>C rs1800470, +25 G>C rs1800471, and +263 C>T rs1800472), showing that CD patients frequently express the TGF-β1 gene genotypes CT and TT at position -509, as compared to noninfected persons; similar results were observed with genotypes TC and CC at codon +10 of the TGF-β1 gene, leading to the conclusion that 509 C>T and +10 T>C TGF-β1 polymorphisms are associated with Chagas disease susceptibility. Studies in genetically different populations susceptible to CD will help to gather new insights and encourage the use of TGF-β as a CD biomarker.

Galectins in Chagas Disease: A Missing Link Between Trypanosoma cruzi Infection, Inflammation, and Tissue Damage

Trypanosoma cruzi, the protozoan parasite causative agent of Chagas disease, affects about seven million people worldwide, representing a major global public health concern with relevant socioeconomic consequences, particularly in developing countries. In this review, we discuss the multiple roles of galectins, a family of β-galactoside-binding proteins, in modulating both T. cruzi infection and immunoregulation. Specifically, we focus on galectin-driven circuits that link parasite invasion and inflammation and reprogram innate and adaptive immune responses. Understanding the dynamics of galectins and their β-galactoside-specific ligands during the pathogenesis of T. cruzi infection and elucidating their roles in immunoregulation, inflammation, and tissue damage offer new rational opportunities for treating this devastating neglected disease.

Influence of galantamine in the inflammatory process and tissular lesions caused by Trypanosoma cruzi QM2 strain

INTRODUCTION

Trypanosoma cruzi infection triggers an inflammatory process with exacerbated production of cytokines that stimulate inflammatory and anti-inflammatory signals, including the efferent anti-inflammatory signal known as the anti-inflammatory cholinergic pathway. Thus, the use of anticholinesterase drugs, such as galantamine, could minimize the inflammatory process caused by this disease.

METHODS

For the study at 30, 60, and 90 days, 120 Swiss mice were divided into three groups. Each group was subdivided into four subgroups: uninfected/untreated (CTRL), uninfected/treated (GAL), infected/untreated (INF), and infected/treated (GAL/INF). The infected groups were inoculated intraperitoneally with 0.1 ml of mouse blood containing 5 × 104 trypomastigote forms of the T. cruzi QM2 strain. The galantamine-treated groups received 5 mg/kg of galantamine orally, through pipetting. From each subgroup, the parameters of parasitemia, histopathological analysis, butyrylcholinesterase activity (BuChE), and functional study of the colon were evaluated.

RESULTS

BuChE performance was observed when AChE was suppressed, with increased activity in the GAL/INF group similar to the INF group on the 30th day post infection, thus corroborating the absence of a significant difference in parasitic curves and histopathological analysis.

CONCLUSIONS

The presence of an inflammatory process and nests of amastigotes, as well as evidence of reactivity to ACh and NOR, suggest that galantamine did not interfere with the colonic inflammatory response or even in colonic tissue parasitism at this stage of Chagas disease.

Genotypic Trypanosoma cruzi distribution and parasite load differ ecotypically and according to parasite genotypes in Triatoma brasiliensis from endemic and outbreak areas in Northeastern Brazil

This study aimed to identify the Trypanosoma cruzi genotypes and their relationship with parasitic load in distinct geographic and ecotypic populations of Triatoma brasiliensis in two sites, including one where a Chagas disease (ChD) outbreak occurred in Rio Grande do Norte state, Brazil. Triatomine captures were performed in peridomestic and sylvatic ecotopes in two municipalities: Marcelino Vieira - affected by the outbreak; and Currais Novos - where high pressure of peridomestic triatomine infestation after insecticide spraying have been reported. The kDNA-PCR was used to select 124 T. cruzi positive triatomine samples, of which 117 were successfully genotyped by fluorescent fragment length barcoding (FFLB). Moreover, the T. cruzi load quantification was performed using a multiplex TaqMan qPCR. Our findings showed a clear ecotypic segregation between TcI and TcII harboured by T. brasiliensis (p<0.001). Although no genotypes were ecotypically exclusive, TcI was predominant in peridomestic ecotopes (86%). In general, T. brasiliensis from Rio Grande do Norte had a higher T. cruzi load varying from 3.94 to 7.66 x 10⁶T. cruzi per insect. Additionally, TcII (median value=299,504 T. cruzi/intestine unit equivalents) had more than twice (p=0.1) the parasite load of TcI (median value=149,077 T. cruzi/intestine unit equivalents), which can be attributed to a more ancient co-evolution with T. brasiliensis. The higher prevalence of TcII in the sylvatic T. brasiliensis (70%) could be associated with a more diversified source of bloodmeals for wild insect populations. Either TcI or TcII may have been responsible for the ChD outbreak that occurred in the city of Marcelino Vieira. On the other hand, a smaller portion of T. brasiliensis was infected by TcIII (3%) in the peridomicile, in addition to T. rangeli genotype A (1%), often found in mixed infections. Our results highlight the need of understanding the patterns of T. cruzi genotype´s development and circulation in insect vectors and reservoirs as a mode of tracking situations of epidemiologic importance, as the ChD outbreak recently recorded for Northeastern Brazil.

Clinical and Epidemiological Characterization of Acute Chagas Disease in Casanare, Eastern Colombia, 2012-2020

Background: Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, is considered a public health problem in Latin America. In Colombia, it affects more than 437,000 inhabitants, mainly in Casanare, an endemic region with eco-epidemiological characteristics that favor its transmission. The objective of this study was to describe the clinical and epidemiological characteristics of the cases of acute CD in Casanare, eastern Colombia, in the period 2012–2020.

Methods: In the present study, 103 medical records of confirmed cases of acute CD were reviewed. The departmental/national incidence and fatality were compared by year; the climatological data of mean temperature, relative humidity, and precipitation per year were reviewed and plotted at IDEAM (Colombian Meteorology Institute) concerning the number of cases of acute CD per month, and it was compared with the frequency of triatomines collected in infested houses by community surveillance. Univariate, bivariate, and multivariate analyses were performed, comparing symptoms and signs according to transmission routes, complications, and age groups.

Results: The incidence was 3.16 cases per 100,000 inhabitants, and the fatality rate was 20% in the study period. The most frequent symptoms included: fever 98.1%, myalgia 62.1%, arthralgia 60.2%, and headache 49.5%. There were significant differences in the frequency of myalgia, abdominal pain, and periorbital edema in oral transmission. The main complications were pericardial effusion, myocarditis, and heart failure in the group over 18 years of age. In Casanare, TcI Discrete Typing Unit (DTU) has mainly been identified in humans, triatomines, and reservoirs such as opossums and dogs and TcBat in bats. An increase in the number of acute CD cases was evidenced in March, a period when precipitation increases due to the beginning of the rainy season.

Conclusions: The results corroborate the symptomatic heterogeneity of the acute phase of CD, which delays treatment, triggering possible clinical complications. In endemic regions, clinical suspicion, diagnostic capacity, detection, and surveillance programs should be strengthened, including intersectoral public health policies for their prevention and control.

In vitro and in vivo trypanocidal activity of a benzofuroxan derivative against Trypanosoma cruzi

Chagas disease, caused by Trypanosoma cruzi, is a major public health problem and is described as one of the most neglected diseases worldwide. It affects about 6-7 million people. Currently, only two drugs are available for the treatment of this disease: nifurtimox and benznidazole. However, both drugs are highly toxic and have several side effects, which lead many patients to discontinue treatment. Moreover, these compounds show a significant curative efficacy only in the acute phase of the disease. Therefore, searching for new drugs is necessary. The objective of this study was to evaluate the in vitro and in vivo activity of a benzofuroxan derivative (EA2) against T. cruzi, and to evaluate the hematological and biochemical changes induced by its treatment in animals infected with T. cruzi. The results were then compared with those of healthy controls. In vitro testing was first performed with T. cruzi epimastigote forms. In this experiment, EA2 was diluted at three different concentrations (0.25, 0.50, and 1%). In vitro evaluation of the trypanocidal activity was performed 24, 48, and 72 h after incubation. In vivo assays were performed using three different doses (10, 5, and 2,5 mg/kg). Mice were divided into 10 groups (five animals/group), wherein four groups comprised non-infected animals (A, G, H, I) and six groups comprised infected animals (B, C, D E, F, J). Groups B and J represented the negative and positive controls, respectively. Groups G, H, and I were used to confirm that EA2 was not toxic to non-infected animals. Parasitemia was measured in infected animals and the hematological and biochemical profiles (urea, creatinine, albumin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase) were evaluated in all animals. EA2 demonstrated in vitro trypanocidal activity at all concentrations tested. Although it did not demonstrate a curative effect in vivo, EA2 was able to retard the onset of parasitemia, and significantly reduced the parasite count in groups D and E (treated with 5 and 2.5 mg/kg, respectively). EA2 did not induce changes in hematological and biochemical parameters in non-infected animals, demonstrating that it is not toxic. However, further assessments should aim to confirm the safety of EA2 since this was the first in vitro and in vivo study conducted with this molecule.

The Selvester QRS score as an estimative of myocardial injury in acute chagasic patients from the Brazilian Amazon

BACKGROUND

In the Brazilian Amazon, a new epidemiological profile of Chagas disease transmission, the oral route, has been detected and cited as being responsible for the increase in acute cases in Brazil. The clinical evaluation of acute Chagas disease (ACD) has been a challenge since it can progress to a chronic phase with cardiac alterations, and the follow-up by modern diagnostic methods is very difficult due to the socio-geographical characteristics of the Brazilian Amazon. Thus, alternatives should be sought to alleviate this problem. We conducted a study to evaluate subjects with ACD using the 12-lead ECG QRS score (Selvester score) as an estimative of myocardial injury progression before and after ACD treatment.

METHODS

The study included indigenous subjects from the Amazon region with ACD in clinical follow-up at the Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD) Chagas Disease outpatient clinic in the state of Amazonas, Brazil. The control group consisted of 31 healthy volunteers with no history of heart disease and no reactive serology for Chagas disease. Baseline ECG was performed in all subjects. The Selvester scoring method was performed according to the standardized guide (< 3 points: no myocardial injury,> 3: points × 3% = % of the predicted LV infarction).

RESULTS

A total of 62 subjects were included, 31 as cases and 31 as controls. The mean follow-up of the case group was 17 months. The control group presented normal ECG. The case group presented 13 alterations before treatment and 11 after. Nineteen individuals presented scores > 3 points, 6 before and 13 after. In 19.36% of subjects, myocardial injury was found before treatment and in 41.94% after treatment.

CONCLUSION

This is the first study that uses the Selvester score (SS) to predict myocardial injury in subjects with ACD. The results of this study suggest the significant presence of myocardial injury from the beginning of treatment to the period post treatment of ACD, which demonstrates that the SS can be applied for stratification and follow-up of Chagas disease in the Amazon region.

Case-fatality From Orally-transmitted Acute Chagas Disease: A Systematic Review and Meta-analysis

Orally-transmitted acute Chagas disease (CD) is emerging as an important public health problem. The prognosis of acute infection following oral transmission is unknown. The aim of this study was to analyze and summarize data on orally-transmitted acute CD. We searched for publications from 1968 to 31 January 2018. We included studies and unpublished data from government sources that reported patients with acute orally-transmitted CD. We identified 41 papers and we added 932 unpublished cases. In all, our study covered 2470 cases and occurrence of 97 deaths. Our meta-analysis estimated that the case-fatality rate was 1.0% (95% CI 0.0-4.0%). Lethality rates have declined over time (P = .02). In conclusion, orally-transmitted acute CD has considerable lethality in the first year after infection. The lethality in symptomatic cases is similar to that from other routes of infection. The lethality rate of orally-acquired disease has declined over the years.

Orbital Cellulitis in Chagas Disease: An Unusual Presentation

Chagas disease is an inflammatory, infectious disease caused by the parasite Trypanosoma cruzi found in the feces of the triatomine bug, which can cause a sudden, brief acute illness, or it may become a long-lasting chronic condition. Chagas disease is common in South America and Central America, however, the constantly expanding global community has brought Chagas disease to the forefront of non-endemic areas, particularly the United States and Europe. The authors present a case of a 47-year-old healthy farmer diagnosed with a right orbital cellulitis refractory to systemic antibiotics. Based on clinical symptoms, the patient's medical/demographical history and a proper differential diagnosis, an acute phase of Chagas disease was diagnosed. After antiparasitic treatment, the patient had a proper recovery and continued with a regular follow-up to monitor the possible development of a chronic phase.

Triatomine home invasions in active foci of Chagas disease in Abaetetuba, Pará, Brazil

BACKGROUND

Chagas disease is a parasitic infection with high re-emergence rates in some Amazon regions. The main vectors of Trypanosoma cruzi are haematophagous insects, the triatomines. Only a few reports are available about the occurrence of these wild vectors and their contact with the inhabitants of the riverside regions of the Amazon. This study describes the unusual behaviour of the triatomines that have invaded the homes of the residents of Abaetetuba, the city that has the second highest number of cases of Chagas disease.

METHODS

Two cross-sectional studies were conducted using sero-epidemiological surveys of the inhabitants of Abaetetuba with registered triatomine home invasions. The frequencies of the variables of interest were analysed using Epi Info version 7.2.

RESULTS

In 2014 and 2017, 145 persons registered home invasions of triatomines in their domiciles and 16.55% reported having been bitten by insects. The environmental features described indicated potential conditions for the persistence of the parasite's life cycle. Of the enrolled inhabitants, 0.47% were positive for immunoglobulin G anti-T. cruzi antibodies.

CONCLUSIONS

Home invasions of triatomines were confirmed in two periods, with a description of unusual behaviour for the genus Rhodnius. The use of serological surveillance in human populations at risk of this occurrence may constitute a new tool for the early detection of silent infections.

Experimental Trypanosoma cruzi Infection Induces Pain in Mice Dependent on Early Spinal Cord Glial Cells and NFκB Activation and Cytokine Production

The neglected tropical infirmity Chagas disease (CD) presents high mortality. Its etiological agent T. cruzi is transmitted by infected hematophagous insects. Symptoms of the acute phase of the infection include fever, fatigue, body aches, and headache, making diagnosis difficult as they are present in other illnesses as well. Thus, in endemic areas, individuals with undetermined pain may be considered for CD. Although pain is a characteristic symptom of CD, its cellular and molecular mechanisms are unknown except for demonstration of a role for peripheral TNF-α in CD pain. In this study, we evaluate the role of spinal cord glial cells in experimental T. cruzi infection in the context of pain using C57BL/6 mice. Pain, parasitemia, survival, and glial and neuronal function as well as NFκB activation and cytokine/chemokine production were assessed. T. cruzi infection induced chronic mechanical and thermal hyperalgesia. Systemic TNF-α and IL-1β peaked 14 days postinfection (p.i.). Infected mice presented increased spinal gliosis and NFκB activation compared to uninfected mice at 7 days p.i. Glial and NFκB inhibitors limited T. cruzi–induced pain. Nuclear phosphorylated NFκB was detected surrounded by glia markers, and glial inhibitors reduced its detection. T. cruzi–induced spinal cord production of cytokines/chemokines was also diminished by glial inhibitors. Dorsal root ganglia (DRG) neurons presented increased activity in infected mice, and the production of inflammatory mediators was counteracted by glial/NFκB inhibitors. The present study unveils the contribution of DRG and spinal cord cellular and molecular events leading to pain in T. cruzi infection, contributing to a better understanding of CD pathology.

Administration of artinm lectin reduces the severity of the acute phase infection with Trypanosoma cruzi

The acute phase of experimental Trypanosoma cruzi infection is associated with a strong inflammatory reaction, physiological changes, amastigote nests in tissues, and hematological alterations. ArtinM, a lectin extracted from Artocarpus heterophyllus seeds, is a homotetramer exhibiting immunomodulatory properties that promotes Th1 immune responses against intracellular pathogens, including the induction of neutrophil migration and increase in IL‐12 production. This study aimed to evaluate the effects of ArtinM on experimental Chagas disease in mice. We evaluated mouse survival curves, parasitemia, hematological parameters including quantification of inflammatory infiltrates, and amastigote nests in cardiac tissue during infection. The results showed a reduced number of parasites in the blood, an increase in animal survival, improvements in hematological parameters, and decrease in inflammatory infiltrates and amastigote nests in the group treated with ArtinM. Collectively, these data suggest that the administration of ArtinM can lower the number of parasites in peak parasitemia caused by the Colombian strain of T. cruzi and can increase survival of infected mice. The observed reduction in cardiac tissue injury may be due to fewer T. cruzi amastigote nests and lower levels of inflammatory infiltrates. This study highlights the need for further investigation into the use of ArtinM as a potential alternative therapeutic for treating Chagas disease.

Chagas Disease in Pregnant Women in the Peruvian Amazon Basin. Cross-Sectional Study

Aims: To assess the prevalence of Chagas disease in pregnant women in Iquitos City, Peru.

Material and Methods: Cross-sectional survey in 300 pregnant women in Iquitos (Peru) from 1 May 2019 to 15 June 2019. Women were tested using an ELISA serology test.

Results: Serology was positive in one case (prevalence: 0.33%; 95% confidence interval: 7.1–13.9%), of a 25-year-old woman who lived in a wooden house with a leaf roof in a periurban area of Iquitos. She was familiar with kissing bugs and had chronic, asymptomatic Chagas disease.

Conclusion: The prevalence of Chagas disease is low in the urban and peri-urban area of the city of Iquitos.

Epidemiological profile of acute Chagas disease in individuals infected by oral transmission in northern Brazil

INTRODUCTION:

Oral infection by Trypanosoma cruzi is currently the most important route of transmission of acute Chagas disease (ACD) in the North region of Brazil, and the reported outbreaks are usually related to ingestion of contaminated food, especially unprocessed açaí pulp.

METHODS

A retrospective cohort study was performed to analyze the epidemiological profile of individuals with suspected cases of ACD in the municipality of Breves, located in the state of Pará, Brazil. Therefore, notifications of suspected cases of ACD were collected from the Municipal Health Department of Breves from January 2007 to December 2017.

RESULTS

A total of 265 individuals were registered, and the majority were male (54.7%; 145/265). Age ranged from nine months to 79 years, with a greater number of notifications for individuals aged between 1 and 39 years (71.3%; 189/265). Most of them had a low level of education (74.3%, 197/265), were living in rural and urban areas (58.9%; 156/265 and 37.7%; 100/265, respectively). Infection occurred mainly in the domestic environment (96.2%; 255/265) through oral transmission (98.1%; 260/265). There were a greater number of notifications in November, December and January.

CONCLUSIONS

These data showed that oral transmission of T. cruzi has become increasingly high in the study region, and health education programs need to be implemented as strategies to ensure good manufacturing practices of unprocessed food.

Clinical, Cardiological and Serologic Follow-Up of Chagas Disease in Children and Adolescents from the Amazon Region, Brazil: Longitudinal Study

BACKGROUND

Outbreaks of Chagas disease (CD) by foodborne transmission is a problem related to deforestation, exposing people to triatomines infected by T. cruzi, in the Amazon region. Once involving long-time follow-up, the treatment efficacy of the CD during its acute phase is still unknown. The authors aim to describe the clinical and epidemiologic profile of children and adolescents with CD, as well as treatment and cardiac involvement during the follow-up. Methods: A descriptive cohort study was conducted from 1998 to 2013 among children and adolescents up to 18 years-old with confirmed diagnosis of CD. All participants met the criteria of CD in the acute phase. Results: A total of 126 outpatients were included and received treatment and follow-up examinations during a medium period of 10.9 years/person. Most of them (68.3%) had their diagnosis established during oral transmission outbreaks. The diagnostic method with the most positive results rate (80.9%) was the IgM class anti-T. cruzi antibody test as an acute phase marker, followed by the thick blood smears (60.8%). Acute myopericarditis was demonstrated in 18.2% of the patients, most of them with favorable evolution, though 2.4% (3/126) persisted with cardiac injury observed at the end point of the follow-up. Conclusions: Antibodies against T. cruzi persisted in 54.8% of sera from the patients without prognostic correlation with cardiac involvement. Precocious treatment can decrease potential cardiac complications and assure good treatment response, especially for inhabitants living in areas with difficult accessibility.

Acute Chagas disease in Brazil from 2001 to 2018: A nationwide spatiotemporal analysis

Background

In Brazil, acute Chagas disease (ACD) surveillance involves mandatory notification, which allows for population-based epidemiological studies. We conducted a nationwide population-based ecological analysis of the spatiotemporal patterns of ACD notifications in Brazil using secondary surveillance data obtained from the Notifiable Diseases Information System (SINAN) maintained by Brazilian Ministry of Health.

Methodology/Principal findings

In this nationwide population-based ecological all cases of ACD reported in Brazil between 2001 and 2018 were included. Epidemiological characteristics and time trends were analyzed through joinpoint regression models and spatial distribution using microregions as the unit of analysis. A total of 5,184 cases of ACD were recorded during the period under study. The annual incidence rate in Brazil was 0.16 per 100,000 inhabitants/year. Three statistically significant changes in time trends were identified: a rapid increase prior to 2005 (Period 1), a stable drop from 2005 to 2009 (Period 2), followed by another increasing trend after 2009 (Period 3). Higher frequencies were noted in males and females in the North (all three periods) and in females in Northeast (Periods 1 and 2) macroregions, as well as in individuals aged between 20–64 years in the Northeast, and children, adolescents and the elderly in the North macroregion. Vectorial transmission was the main route reported during Period 1, while oral transmission was found to increase significantly in the North during the other periods. Spatiotemporal distribution was heterogeneous in Brazil over time. Despite regional differences, over time cases of ACD decreased significantly nationwide. An increasing trend was noted in the North (especially after 2007), and significant decreases occurred after 2008 among all microregions other than those in the North, especially those in the Northeast and Central-West macroregions.

Conclusions/Significance

In light of the newly identified epidemiological profile of CD transmission in Brazil, we emphasize the need for strategically integrated entomological and health surveillance actions.

Chagas disease (CD) infection is a debilitating and neglected disease that occurs in 21 Latin America countries. CD has two distinct phases: acute and chronic. The generally asymptomatic acute phase begins shortly after infection and can last up to four months. When symptoms do appear, they are typically mild and unspecific. Following this phase, infected individuals evolve to a long-lasting chronic phase, which can be either symptomatic or asymptomatic. In Brazil, only acute cases are mandatorily notifiable in the Brazilian Notifiable Diseases Information System (Brazilian Ministry of Health). Most chronic cases are unknown and untreated. Considering that epidemiological data related to ACD is publicly available, we have analyzed the spatiotemporal distribution of notified cases of ACD and evaluated relevant epidemiological indicators throughout Brazil from 2001 to 2018. The data present here may contribute to surveillance actions designed at preventing new CD cases. We observed 5,184 cases of ACD during the period under study. The annual incidence rate in Brazil was 0.16 per 100,000 inhabitants/year. Three distinct epidemiological periods were identified: a rapid increase prior to 2005 (Period 1), a stable drop from 2005 to 2009 (Period 2), followed by another increasing trend after 2009 (Period 3). Vectorial transmission was the main route reported during Period 1, while oral transmission was found to increase significantly in the North during the other periods. Despite regional differences, over time cases of ACD decreased significantly nationwide. An increasing trend was noted in the North (especially after 2007). In light of the newly identified epidemiological profile of CD transmission in Brazil, we emphasize the need for strategically integrated entomological and health surveillance actions.

Death due to acute Chagas -related myocarditis in a child: a case report

This is a case report about the only confirmed death in the State of Espírito Santo due to acute Chagas-related myocarditis in a 2-year-old child living in the rural area of Guarapari. He presented with fever, abdominal pain, headache, and vomiting, resulting in death 21 days after the presentation of symptoms. Amastigote forms were observed in the myocardial fibers in histological examination. The boy's mother had reported finding "kissing bugs" in the child's hand. This case highlights the need to include Chagas disease in the differential diagnosis in health care to provide early treatment and avoid death in affected individuals.

WHF IASC Roadmap on Chagas Disease

Background

Chagas Disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi, with some of the most serious manifestations affecting the cardiovascular system. It is a chronic, stigmatizing condition, closely associated with poverty and affecting close to 6 million people globally. Although historically the disease was limited to endemic areas of Latin America recent years have seen an increasing global spread. In addition to the morbidity and mortality associated with the disease, the social and economic burdens on individuals and society are substantial. Often called the 'silent killer', Chagas disease is characterized by a long, asymptomatic phase in affected individuals. Approximately 30% then go on develop chronic Chagas cardiomyopathy and other serious cardiac complications such as stroke, rhythm disturbances and severe heart failure.

Methods

In a collaboration of the World Hearth Federation (WHF) and the Inter-American Society of Cardiology (IASC) a writing group consisting of 20 diverse experts on Chagas disease (CD) was convened. The group provided up to date expert knowledge based on their area of expertise. An extensive review of the literature describing obstacles to diagnosis and treatment of CD along with proposed solutions was conducted. A survey was sent to all WHF Members and, using snowball sampling to widen the consultation, to a variety of health care professionals working in the CD global health community. The results were analyzed, open comments were reviewed and consolidated, and the findings were incorporated into this document, thus ensuring a consensus representation.

Results

The WHF IASC Roadmap on Chagas Disease offers a comprehensive summary of current knowledge on prevention, diagnosis and management of the disease. In providing an analysis of 'roadblocks' in access to comprehensive care for Chagas disease patients, the document serves as a framework from which strategies for implementation such as national plans can be formulated. Several dimensions are considered in the analysis: healthcare system capabilities, governance, financing, community awareness and advocacy.

Conclusion

The WHF IASC Roadmap proposes strategies and evidence-based solutions for healthcare professionals, health authorities and governments to help overcome the barriers to comprehensive care for Chagas disease patients. This roadmap describes an ideal patient care pathway, and explores the roadblocks along the way, offering potential solutions based on available research and examples in practice. It represents a call to action to decision-makers and health care professionals to step up efforts to eradicate Chagas disease.

DNA lesions and repair in trypanosomatids infection

Pathological processes such as bacterial, viral and parasitic infections can generate a plethora of responses such as, but not restricted to, oxidative stress that can be harmful to the host and the pathogen. This stress occurs when there is an imbalance between reactive oxygen species produced and antioxidant factors produced in response to the infection. This imbalance can lead to DNA lesions in both infected cells as well as in the pathogen. The effects of the host response on the parasite lead to several kinds of DNA damage, causing alterations in the parasite's metabolism; the reaction and sensitivity of the parasite to these responses are related to the DNA metabolism and life cycle of each parasite. The present review will discuss the survival strategies developed by host cells and Trypanosoma cruzi, focusing on the DNA repair mechanisms of these organisms throughout infection including the relationship between DNA damage, stress response features, and the unique characteristics of these diseases.

Human acute Chagas disease: changes in factor VII, activated protein C and hepatic enzymes from patients of oral outbreaks in Pará State (Brazilian Amazon)

Oral transmission of Chagas disease has been increasing in Latin American countries. The present study aimed to investigate changes in hepatic function, coagulation factor levels and parasite load in human acute Chagas disease (ACD) secondary to oral Trypanosoma cruzi transmission. Clinical and epidemiological findings of 102 infected individuals attended in the State of Pará from October 2013 to February 2016 were included. The most common symptoms were fever (98%), asthenia (83.3%), face and limb edema (80.4%), headache (74.5%) and myalgia (72.5%). The hepatic enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of 30 ACD patients were higher compared with controls, and this increase was independent of the treatment with benznidazole. Moreover, ACD individuals had higher plasma levels of activated protein C and lower levels of factor VII of the coagulation cascade. Patients with the highest parasite load had also the most increased transaminase levels. Also, ALT and AST were associated moderately (r = 0.429) and strongly (r = 0.595) with parasite load respectively. In conclusion, the present study raises the possibility that a disturbance in coagulation and hepatic function may be linked to human ACD.

A deadly feast: Elucidating the burden of orally acquired acute Chagas disease in Latin America - Public health and travel medicine importance

Over the past two decades, several countries in Latin American, particularly Brazil, Venezuela, and Colombia, have experienced multiple outbreaks of oral Chagas disease. Transmission occurs secondary to contamination of food or beverages by triatomine (kissing bug) feces containing infective Trypanosoma cruzi metacyclic trypomastigotes. Orally transmitted infections are acute and potentially fatal. Oral Chagas transmission carries important clinical implications from management to public health policies compared to vector-borne transmission. This review aims to discuss the contemporary situation of orally acquired Chagas disease, and its eco-epidemiology, pathogenesis, and clinical management. We also propose preventive public health interventions to reduce the burden of disease and provide important perspectives for travel medicine. Travel health advisors need to counsel intending travellers to South America on avoidance of "deadly feasts" - risky beverages such as fruit juices including guava juice, bacaba, babaçu and palm wine (vino de palma), açai pulp, sugar cane juice and foodstuffs such as wild animal meats that may be contaminated with T. cruzi.

Fatal evolution of acute Chagas disease in a child from Northern Brazil: factors that determine poor prognosis

Trypanosoma cruzi is the causative agent of Chagas disease. Nowadays, the transmission in Brazil occurs mainly by oral ingestion of contaminated food that has been associated with more severe clinical manifestations. We report a case of Acute Chagas disease caused by oral transmission in a child from Northern Brazil. In the hospital admission, physical examination showed tachycardia, hepatomegaly, bipalpebral edema and anasarca. Trypanosoma cruzi trypomastigotes were found in microscopy during blood cell count. Twenty-three days before hospitalization, the child had ingested the "bacaba palm fruit's wine". Even with the appropriate diagnosis and starting of treatment, she did not survive. Quantitative analysis of Trypanosoma cruzi DNA in a blood sample resulted in 54,053.42 parasite equivalents/mL and the DTU TcIV was identified. The outcome may have been determined by several factors, including the delay to seek a medical service beyond the high parasitemia, detected by qPCR. DTU TcIV could also have influenced the natural history of the disease.

Oral Route Driven Acute Trypanosoma cruzi Infection Unravels an IL-6 Dependent Hemostatic Derangement

Oral transmission of Trypanosoma cruzi, the etiologic agent of Chagas disease, is presently the most important route of infection in Brazilian Amazon. Other South American countries have also reported outbreaks of acute Chagas disease associated with food consumption. A conspicuous feature of this route of transmission is presenting symptoms such as facial and lower limbs edema, in some cases bleeding manifestations and risk of thromboembolism are evident. Notwithstanding, studies that address this route of infection are largely lacking regarding its pathogenesis and, more specifically, the crosstalk between immune and hemostatic systems. Here, BALB/c mice were orally infected with metacyclic trypomastigotes of T. cruzi Tulahuén strain and used to evaluate the cytokine response, primary and secondary hemostasis during acute T. cruzi infection. When compared with control uninfected animals, orally infected mice presented higher pro-inflammatory cytokine (TNF-α, IFN-γ, and IL-6) serum levels. The highest concentrations were obtained concomitantly to the increase of parasitemia, between 14 and 28 days post-infection (dpi). Blood counts in the oral infected group revealed concomitant leukocytosis and thrombocytopenia, the latter resulting in increased bleeding at 21 dpi. Hematological changes paralleled with prolonged activated partial thromboplastin time, Factor VIII consumption and increased D-dimer levels, suggest that oral T. cruzi infection relies on disseminated intravascular coagulation. Remarkably, blockade of the IL-6 receptor blunted hematological abnormalities, revealing a critical role of IL-6 in the course of oral infection. These results unravel that acute T. cruzi oral infection results in significant alterations in the hemostatic system and indicates the relevance of the crosstalk between inflammation and hemostasis in this parasitic disease.

Could angiotensin-modulating drugs be relevant for the treatment of Trypanosoma cruzi infection? A systematic review of preclinical and clinical evidence

Although leucocytes are targets of renin-angiotensin system (RAS) effector molecules and RAS-modulating drugs exert immunomodulatory effects, their impact onTrypanosoma cruziinfection remains poorly understood. By using the framework of a systematic review, we integrated the preclinical and clinical evidence to investigate the relevance of angiotensin-inhibiting drugs onT. cruziinfections. From a comprehensive and structured search in biomedical databases, only original studies were analysed. In preclinical and clinical studies, captopril, enalapril and losartan were RAS-modulating drugs used. The mainin vitrofindings indicated that these drugs increased parasite uptake per host cells, IL-12 expression by infected dendritic cells and IFN-γby T lymphocytes, in addition to attenuating IL-10 and IL-17 production by CD8 + T cells. In animal models, reduced parasitaemia, tissue parasitism, leucocytes infiltration and mortality were often observed inT. cruzi-infected animals receiving RAS-modulating drugs. In patients with Chagas’ disease, these drugs exerted a controversial impact on cytokine and hormone levels, and a limited effect on cardiovascular function. Considering a detailed evaluation of reporting and methodological quality, the current preclinical and clinical evidence is at high risk of bias, and we hope that our critical analysis will be useful in mitigating the risk of bias in further studies.

Cardiac Evaluation in the Acute Phase of Chagas' Disease with Post-Treatment Evolution in Patients Attended in the State of Amazonas, Brazil

Background

In the past two decades, a new epidemiological profile of Chagas' disease (CD) has been registered in the Brazilian Amazon where oral transmission has been indicated as responsible for the increase of acute cases. In the Amazonas state, five outbreaks of acute CD have been registered since 2004. The cardiac manifestations in these cases may be characterized by diffuse myocarditis, with alteration in the electrocardiogram (ECG) and transthoracic echocardiogram (TTE).

Objective

To perform a cardiac evaluation in autochthonous patients in the acute phase and at least one year after submitted to treatment for acute CD and evaluate the demographic variables associated with the presence of cardiac alterations.

Methods

We evaluated patients diagnosed with acute CD through direct parasitological or serological (IgM) methods from 2007 to 2015. These patients were treated with benznidazole and underwent ECG and TTE before and after treatment. We assumed a confidence interval of 95% (CI 95%, p < 0.05) for all variables analyzed.

Results

We observed 63 cases of an acute CD in which oral transmission corresponded to 75%. Cardiac alterations were found in 33% of the cases, with a greater frequency of ventricular repolarization alteration (13%), followed by pericardial effusion (10%) and right bundle branch block and left anterior fascicular block (2%). The follow-up occurred in 48 patients with ECG and 25 with TTE for a mean period of 15.5 ± 4.1 months after treatment. Of these, 8% presented normalization of the cardiac alterations in ECG, 62.5% remained with the normal exams. All of the patients presented normal results in TTE in the post-treatment period. As for the demographic variables, isolated cases presented more cardiac alterations than outbreaks (p = 0.044) as well as cases from Central Amazonas mesoregion (p = 0.020).

Conclusions

Although cardiac alterations have not been frequent in most of the studied population, a continuous evaluation of the clinical-epidemiological dynamics of the disease in the region is necessary in order to establish preventive measures.

Type 1 cardiorenal syndrome in a patient with an acute infection caused by Trypanosoma cruzi in the Brazilian Amazon region - a case report

Cardiorenal syndrome type 1 (CRS 1) occurs when acute heart failure leads to acute kidney injury. There are several etiologies of CRS 1, including Chagas disease. Here, we present the first case report of CRS 1 in a patient with acute Chagas disease. Electrocardiography, transthoracic echocardiography, and cardiac magnetic resonance imaging showed signs of acute myocarditis. Laboratory examination revealed severe loss of kidney function, with a creatinine clearance of 30 mL/min, which fully normalized after treatment. Due to emergence of Chagas disease in the Brazilian Amazon, it is important to report unique clinical features in order to improve patients' outcomes.

The economic value of identifying and treating Chagas disease patients earlier and the impact on Trypanosoma cruzi transmission

BACKGROUND

The World Health Organization's 2020 Goals for Chagas disease include access to antiparasitic treatment and care of all infected/ill patients. Policy makers need to know the economic value of identifying and treating patients earlier. However, the economic value of earlier treatment to cure and prevent the Chagas' spread remains unknown.

METHODS

We expanded our existing Chagas disease transmission model to include identification and treatment of Chagas disease patients. We linked this to a clinical and economic model that translated chronic Chagas disease cases into health and economic outcomes. We evaluated the impact and economic outcomes (costs, cost-effectiveness, cost-benefit) of identifying and treating different percentages of patients in the acute and indeterminate disease states in a 2,000-person village in Yucatan, Mexico.

RESULTS

In the absence of early treatment, 50 acute and 22 new chronic cases occurred over 50 years. Identifying and treating patients in the acute stage averted 0.5-5.4 acute cases, 0.6-5.5 chronic cases, and 0.6-10.8 disability-adjusted life years (DALYs), saving $694-$7,419 and $6,976-$79,950 from the third-party payer and societal perspectives, respectively. Treating in the indeterminate stage averted 2.2-4.9 acute cases, 6.1-12.8 chronic cases, and 11.7-31.1 DALYs, saving $7,666-$21,938 from the third-party payer perspective and $90,530-$243,068 from the societal perspective. Treating patients in both stages averted ≤9 acute cases and ≤15 chronic cases. Identifying and treating patients early was always economically dominant compared to no treatment. Identifying and treating patients earlier resulted in a cumulative cost-benefit of $7,273-$224,981 at the current cost of identification and treatment.

CONCLUSIONS

Even when identifying and treating as little as 5% of cases annually, treating Chagas cases in the acute and indeterminate stages reduces transmission and provides economic and health benefits. This supports the need for improved diagnostics and access to safe and effective treatment.

Trypanosoma cruzi genetic diversity: Something new for something known about Chagas disease manifestations, serodiagnosis and drug sensitivity

The genetic diversity of Trypanosoma cruzi, the protozoan agent of Chagas disease, is widely recognized. At present, T. cruzi is partitioned into seven discrete typing units (DTUs), TcI-TcVI and Tcbat. This article reviews the present knowledge on the parasite population structure, the evolutionary relationships among DTUs and their distinct, but not exclusive ecological and epidemiological associations. Different models for the origin of hybrid DTUs are examined, which agree that genetic exchange among T. cruzi populations is frequent and has contributed to the present parasite population structure. The geographic distribution of the prevalent DTUs in humans from the southern United States to Argentina is here presented and the circumstantial evidence of a possible association between T. cruzi genotype and Chagas disease manifestations is discussed. The available information suggests that parasite strains detected in patients, regardless of the clinical presentation, reflect the principal DTU circulating in the domestic transmission cycles of a particular region. In contrast, in several orally transmitted outbreaks, sylvatic strains are implicated. As a consequence of the genotypic and phenotypic differences of T. cruzi strains and the differential geographic distribution of DTUs in humans, regional variations in the sensitivity of the serological tests are verified. The natural resistance to benznidazole and nifurtimox, verified in vivo and in vitro for some parasite stocks, is not associated with any particular DTU, and does not explain the marked difference in the anti-parasitic efficacy of both drugs in the acute and chronic phases of Chagas disease. Throughout this review, it is emphasized that the interplay between parasite and host genetics should have an important role in the definition of Chagas disease pathogenesis, anti-T. cruzi immune response and chemotherapy outcome and should be considered in future investigations.

Imaging the development of chronic Chagas disease after oral transmission

Chagas disease is a zoonosis caused by the protozoan parasite Trypanosoma cruzi. Transmission cycles are maintained by haematophagous triatomine bug vectors that carry infective T. cruzi in their faeces. Most human infections are acquired by contamination of mucosal membranes with triatomine faeces after being bitten, however, T. cruzi can be transmitted by several other routes. Oral transmission is an increasingly important aspect of Chagas disease epidemiology, typically involving food or drink products contaminated with triatomines. This has recently caused numerous outbreaks and been linked to unusually severe acute infections. The long-term impact of oral transmission on infection dynamics and disease pathogenesis is unclear. We used highly sensitive bioluminescence imaging and quantitative histopathology to study orally transmitted T. cruzi infections in mice. Both metacyclic and bloodform trypomastigotes were infectious via the oral cavity, but only metacyclics led to established infections by intra-gastric gavage. Mice displayed only mild acute symptoms but later developed significantly increased myocardial collagen content (p = 0.017), indicative of fibrosis. Gastrointestinal tissues and skin were the principal chronic infection reservoirs. Chronic phase parasite load profiles, tissue distribution and myocardial fibrosis severity were comparable to needle-injected controls. Thus, the oral route neither exacerbates nor ameliorates experimental Chagas disease.

Acute Chagas disease in the state of Pará, Amazon Region: is it increasing?

Acute Chagas disease (ACD) has a distinct epidemiological profile in the Amazon Region, with cases and outbreaks of Trypanosoma cruzi infection being possibly related to the ingestion of contaminated food. Data on ACD in the state of Pará retrieved from 2000 to 2016 from the Brazilian Notifiable Diseases Information System (SINAN) were evaluated. During this period, 2,030 of the 16,807 reported cases were confirmed, with a higher incidence between the months of August and December, thus characterising a seasonal pattern of acute infection, and coinciding with the higher production of “açaí”, one fruit likely involved in the oral transmission of the disease. Evaluation of the absolute numbers of confirmed ACD cases secondary to oral infection suggests that infection through this route increased during the 2010-2016 period, differing from what was recorded in terms of vectorial or other infection routes. These findings point to the need of intensifying strategies to prevent or substantially reduce oral transmission.

Development of a Trypanosoma cruzi strain typing assay using MS2 peptide spectral libraries (Tc-STAMS2)

Background

Chagas disease also known as American trypanosomiasis is caused by the protozoan Trypanosoma cruzi. Over the last 30 years, Chagas disease has expanded from a neglected parasitic infection of the rural population to an urbanized chronic disease, becoming a potentially emergent global health problem. T. cruzi strains were assigned to seven genetic groups (TcI-TcVI and TcBat), named discrete typing units (DTUs), which represent a set of isolates that differ in virulence, pathogenicity and immunological features. Indeed, diverse clinical manifestations (from asymptomatic to highly severe disease) have been attempted to be related to T.cruzi genetic variability. Due to that, several DTU typing methods have been introduced. Each method has its own advantages and drawbacks such as high complexity and analysis time and all of them are based on genetic signatures. Recently, a novel method discriminated bacterial strains using a peptide identification-free, genome sequence-independent shotgun proteomics workflow. Here, we aimed to develop a Trypanosoma cruzi Strain Typing Assay using MS/MS peptide spectral libraries, named Tc-STAMS2.

Methods/Principal findings

The Tc-STAMS2 method uses shotgun proteomics combined with spectral library search to assign and discriminate T. cruzi strains independently on the genome knowledge. The method is based on the construction of a library of MS/MS peptide spectra built using genotyped T. cruzi reference strains. For identification, the MS/MS peptide spectra of unknown T. cruzi cells are identified using the spectral matching algorithm SpectraST. The Tc-STAMS2 method allowed correct identification of all DTUs with high confidence. The method was robust towards different sample preparations, length of chromatographic gradients and fragmentation techniques. Moreover, a pilot inter-laboratory study showed the applicability to different MS platforms.

Conclusions and significance

This is the first study that develops a MS-based platform for T. cruzi strain typing. Indeed, the Tc-STAMS2 method allows T. cruzi strain typing using MS/MS spectra as discriminatory features and allows the differentiation of TcI-TcVI DTUs. Similar to genomic-based strategies, the Tc-STAMS2 method allows identification of strains within DTUs. Its robustness towards different experimental and biological variables makes it a valuable complementary strategy to the current T. cruzi genotyping assays. Moreover, this method can be used to identify DTU-specific features correlated with the strain phenotype.

Chagas disease is one of the most important neglected diseases with an estimated number of 6–7 million infected individuals, the majority living in Central and South America. The Trypanosoma cruzi (T.cruzi) protozoan parasite is the etiological agent of Chagas disease. T.cruzi is highly genetically diverse and a new nomenclature assigned each strain to seven genetic groups (TcI-TcVI and Tcbat), named Discrete Typing Units (DTUs), based on their biochemical, immunological and phenotypical characteristics. T.cruzi DTUs have been correlated to diverse clinical outcomes highlighting the importance of molecular epidemiological screens. Despite the development of T.cruzi typing methods based on genetic signatures, each method presents its own advantages and challenges. The work presented here shows the application of mass spectrometry for Trypanosoma cruzi Strain Typing Assay using MS² peptide spectral libraries (Tc-STAMS2). The novelty of the method is based on the use of peptide fragmentation spectra as strain-specific fingerprints to classify and identify DTUs. Initially, a spectra library is generated from characterized T.cruzi strains. The library is subsequently inspected using MS/MS spectra from unknown strains and confidently assigned to a specific strain in an automated and computationally-driven approach. The Tc-STAMS2 method was challenged to test several variables such as sample type and preparation, instrument setup and identification platform. Tc-STAMS2 provided high confidence and robustness in T.cruzi strain typing. The Tc-STAMS2 method represents a proof-of-concept of a complementary strategy to the current DNA-based T. cruzi genotyping methods. Moreover, the method allows the identification of strain-specific features that could be related to the biology of T.cruzi strains and their clinical outcomes.

Are the London Declaration's 2020 goals sufficient to control Chagas disease?: Modeling scenarios for the Yucatan Peninsula

BACKGROUND

The 2020 Sustainable Development goals call for 100% certified interruption or control of the three main forms of Chagas disease transmission in Latin America. However, how much will achieving these goals to varying degrees control Chagas disease; what is the potential impact of missing these goals and if they are achieved, what may be left?

METHODS

We developed a compartmental simulation model that represents the triatomine, human host, and non-human host populations and vector-borne, congenital, and transfusional T. cruzi transmission between them in the domestic and peridomestic settings to evaluate the impact of limiting transmission in a 2,000 person virtual village in Yucatan, Mexico.

RESULTS

Interruption of domestic vectorial transmission had the largest impact on T. cruzi transmission and prevalence in all populations. Most of the gains were achieved within the first few years. Controlling vectorial transmission resulted in a 46.1-83.0% relative reduction in the number of new acute Chagas cases for a 50-100% interruption in domestic vector-host contact. Only controlling congenital transmission led to a 2.4-8.1% (30-100% interruption) relative reduction in the total number of new acute cases and reducing only transfusional transmission led to a 0.1-0.3% (30-100% reduction). Stopping all three forms of transmission resulted in 0.5 total transmission events over five years (compared to 5.0 with no interruption); interrupting all forms by 30% resulted in 3.4 events over five years per 2,000 persons.

CONCLUSIONS

While reducing domestic vectorial, congenital, and transfusional transmission can successfully reduce transmission to humans (up to 82% in one year), achieving the 2020 goals would still result in 0.5 new acute cases per 2,000 over five years. Even if the goals are missed, major gains can be achieved within the first few years. Interrupting transmission should be combined with other efforts such as a vaccine or improved access to care, especially for the population of already infected individuals.

Surveillance of seroepidemiology and morbidity of Chagas disease in the Negro River, Brazilian Amazon

BACKGROUND

Chagas disease in the Brazilian Amazon Region was previously regarded as an enzootic disease of wild animals. More recently, in situations where humans have penetrated the wild ecotope or where triatomines and/or wild animals (marsupials) have invaded human homes resulting in disease transmission, Chagas disease has come to be regarded as an anthropozoonosis. We found that the highest incidence of infection due to Trypanosoma cruzi and Chagas disease occurred among piassaba fibre gatherers and their families.

OBJECTIVES

Considering the results of previous surveys, we conducted a new survey of piassaba gatherers and their families in the creeks of the Aracá, Curuduri, Demini, Ererê and Padauiri rivers, which are tributaries on the left bank of the Negro River, in the municipality of Barcelos; Barcelos-Caurés highway; Negro River in Santa Isabel of the Negro River; and Marié River, on the right bank of the Negro River.

METHODS

A questionnaire was applied to 482 piassaba gatherers and their families who accompanied them. We collected 5-mL blood samples (with permission from each subject), separated the serum, and performed serological tests using indirect immunofluorescence and conventional and recombinant enzyme-linked immunosorbent assays (ELISA). We performed brief clinical examination and electrocardiograms. Only 273 subjects attended our field base for detailed clinical examination and electrocardiogram.

FINDINGS AND MAIN CONCLUSIONS

The questionnaire revealed that 100% of the 482 patients recognised the triatomine Rhodnius brethesi, which they had seen in the piassaba plantation and 81% in their field huts. A total of 79% of subjects had previously been bitten by this vector and 21% did not know. The 25 subjects seropositive for T. cruzi infection (5.2%) stated that they had been bitten more than 10 times by this insect. Of the 273 subjects who underwent electrocardiogram, 22% showed conditions that were possibly attributable to Chagas disease or other cardiovascular disease.