Diagnosis Of Chagas Disease Research Articles

P-140. A Quality Improvement (QI) Project to Increase Chagas Disease Screening Rates in an At-Risk, Underserved Patient Population Living in Houston, Texas

Abstract Background Chagas disease (CD), caused by Trypanosoma cruzi, is a neglected disease of poverty affecting >6 million people in the Americas, including >200,000 in the US. While many are asymptomatic, 20-30% develop end-organ damage like Chagas cardiomyopathy. Early diagnosis and treatment are essential to reduce this risk; however, US clinicians generally are unaware of for whom CD screening is recommended (Table 1) and how to order it. >1.5 million people born in continental Latin America live in Harris County, TX, making this an important region in which to establish systematic CD screening. This QI project seeks to improve CD screening rates using electronic medical record (EMR) tools.Figure 1A:HHS Chagas disease testing protocol, Figure 1B: Outpatient clinic visit flow diagram incorporating PDSA Cycle Phase 1 and Phase 2 Methods This project is set in the Harris Health System (HHS), a public safety-net healthcare system serving >1 million outpatients annually; 52.9% are Hispanic and 45.9% are uninsured. Previous studies support a CD prevalence of ∼1%, suggesting that >5,000 outpatients/year present to HHS with undiagnosed CD. Our HHS CD screening protocol (Figure 1A) is based on US screening recommendations. We assembled a team of stakeholders and identified a HHS primary care clinic (MLK Clinic) as the pilot location. We used Epic Systems EMR tools to evaluate the patient population presenting to MLK Clinic over a 9 month period and develop corresponding QI interventions. The primary outcome is CD screening rate; see Table 2 for secondary outcomes.Figure 2:Plan, Do, Study, Act (PDSA) cycle structure Results 1,443 patients presented to MLK Clinic between 7/1/2023-4/30/2024, average age 26 years (range 0-95). A sample of 158 showed that 40% were eligible for CD screening based on birth country. Of those, only 12 T. cruzi IgG tests were ordered (2% of eligible patients). Together with stakeholders, we developed 2 interventions to improve CD screening rates (Figure 1B): 1) single-question Epic SmartPhrase used by nursing staff during patient triage and 2) physician CD educational session and Epic SmartPhrase. These will be applied in 2 PDSA cycle phases (Figure 2). We trained nursing staff on 4/2024 and began PDSA Phase 1 on 5/1/24. Conclusion Early CD diagnosis and treatment reduce the risk of progression to devastating end-organ damage. This QI project will contribute to improved identification of at-risk patients through use of EMR tools for systematic screening. Disclosures All Authors: No reported disclosures

A specific, stable, and accessible LAMP assay targeting the HSP70 gene of Trypanosoma cruzi.

Diagnostic delays prevent most Chagas disease patients from receiving timely therapy during the acute phase when treatment is effective. qPCR-based diagnostic methods provide high sensitivity during this phase but require specialized equipment and complex protocols. More simple and cost-effective tools are urgently needed to optimize early Chagas disease diagnosis in low-income endemic regions. Here, we present a loop-mediated isothermal amplification (LAMP) that targets a highly conserved region in the HSP70 gene of Trypanosoma cruzi, the causative agent of Chagas disease. This assay demonstrates species-specific amplification across multiple parasite genetic lineages while maintaining stability after 2 hours of incubation and at least 8 months of storage at -20°C. Moreover, the assay is at least 12 times less expensive than the TaqMan qPCR that is currently routinely used for acute Chagas diagnostics. Population-based validation in 100 infants born to Chagas-positive mothers in Santa Cruz, Bolivia, yielded a specificity of 100% and sensitivity exceeding 77% when compared to a TaqMan qPCR that targets satellite DNA. This cost-effective assay holds promise for large-scale diagnosis of Chagas disease in endemic regions with limited resources.

Congenital Chagas disease: A cohort study to assess molecular diagnostic methods at the Chagas disease national reference center of Argentina.

Trypanosoma cruzi is a protozoan parasite which causes Chagas disease. Mother-to-child transmission is the main route of transmission in vector-free areas. Congenital Chagas disease refers specifically to cases arising from this route of transmission. This work evaluates the clinical sensitivity of two qPCR techniques for diagnosis of congenital Chagas disease. The study was developed in the National Institute of parasitology (NIP), Argentina, and Pan-American Health Organization/ Word Health Organization Collaborating Center for Chagas Disease. Between July 2014 and May 2018, a prospective cohort study was carried out with 499 children born to seropositive for T. cruzi infection included. The performance of qPCR techniques was compared with the gold standard diagnostic algorithm for Congenital Chagas disease (CCD-GS), which comprises performing more than one parasitological test on children from birth until nine months of age, and serology from ten months of age. Of the 961 babies born to women seropositive for Chagas disease who were attended at the NIP laboratory, 462 did not meet the study inclusion criteria; 22 cases were diagnosed with congenital Chagas disease. qPCR showed 100% clinical sensitivity and 98 to 100% clinical specificity for the diagnosis of congenital Chagas disease compared with CCD-GS algorithm. The results obtained in this study demonstrate the clinical accuracy and effectiveness of qPCR SatDNA and qPCR kDNA for diagnosis of congenital Chagas disease. It could be a powerful tool for chagas test and treat strategies to reduce late complications of the disease. This work was financed by the INP Dr. Mario Fatala Chaben, ANLIS Dr. Carlos G. Malbran.

Eco-epidemiological aspects and risk factors associated with human Chagas disease in rural areas of the state of Piauí, Brazil

BackgroundPiauí is located in Northeastern Brazil, an endemic area for Chagas disease, with the Brazilian semiarid representing the second region in number of people infected by the parasite Trypanosoma cruzi. The state of Piauí is one of the most socially vulnerable territories with direct impact on the access to diagnosis and treatment of Chagas disease for the population living in rural communities. Triatoma brasiliensis is the vector species of greatest epidemiological importance in Northeastern Brazil. We investigated the triatomine fauna and risk factors associated to T. cruzi transmission in two municipalities, Pedro II and Oeiras, located in different mesoregions of Piauí.MethodsTwenty-three rural areas were selected for triatomines search and serological survey of the population. The analysis of triatomines consisted on identifying T. cruzi infection index by microscopy and kDNA-PCR followed by parasite genotyping through the use of multilocus PCR to characterize the discrete typing units (DTUS), and the identification of food sources using PCR directed to the 12S rRNA gene of vertebrates and sequencing.ResultsA total of 1,043 triatomines identified as T. brasiliensis, Triatoma pseudomaculata, Rhodnius nasutus, Rhodnius sp. and Panstrongylus lutzi were collected. The overall positivity for T. cruzi was 4.6% and 11.4% by microscopy and kDNA-PCR, respectively. The DTUs TcV (∼ 44%) and TcI (∼ 43%) were the most prevalent in either single or mixed infections. This is the first report of TcV and TcVI infections in vectors of Piauí. The most frequent blood source was Homo sapiens (46.5%), of which ∼ 42% individuals (28/67) were collected indoors and four of them (14.3%) tested positive for T. cruzi kDNA in Pedro II. Chicken (∼ 19%), domestic cat (∼ 17%) and others were also identified as feeding sources for triatomines. Serological survey revealed 2% seroprevalence. Variables as age over 60 years (p = 0.01), Black race (p = 0.002) and occupation as retired (p = 0.004) significantly influenced the seropositivity.ConclusionDespite the reduced seroprevalence of the population, the epidemiological scenario of Chagas disease in both municipalities highlights the risk of the re-emergence of domestic vector-borne transmission. Ensuring continued entomological surveillance and vector control programs and providing access to diagnosis and treatment for the susceptible population are still needed.

Assessment of Alinity s Chagas® as a Primary Diagnostic Test for Chronic Chagas Disease in a Non-Endemic Area of Europe (Barcelona, Spain).

Chagas disease (CD) has become a worldwide problem due to globalization. In Europe, most cases are imported and are diagnosed in the chronic phase by two serological tests, as recommended by the World Health Organization. Chemiluminescent microparticle immunoassays (CMIAs) are an emerging alternative to the diagnostic standard. We aimed to validate the CMIA Alinity s Chagas® as a primary diagnostic test for chronic CD following its replacement of Architect Chagas®, with an amended signal-to-cut-off (S/CO) ratio of ≥6. Laboratory results and clinical data were collected retrospectively from 774 sera from an at-risk population tested for CD in Barcelona during 2020-2022. Negative results required no further testing, and those with a S/CO ratio ≥ 0.8 were confirmed by a second serological assay, according to the common practice. Four per cent of the samples (31/774) were determined to be seropositive by Alinity s, 93.5% of which (29/31) had an S/CO ratio ≥ 6. Almost all the samples could be directly classified by the corrected S/CO. Alinity s Chagas® was validated as a single test for chronic CD diagnosis by raising the S/CO to ≥6. Its implementation could provide faster results and help reduce CD underdiagnosis in non-endemic countries.

Enhancing patient care: a multimodality strategy for dilated cardiomyopathy in Chagas disease

Chagas disease is a systemic illness characterized by acute and chronic phases. If untreated, it can lead to dysfunction of vital organs, notably the heart, ultimately resulting in heart failure. Transmission primarily occurs through the feces of triatomine insects carrying the protozoan parasite Trypanosoma cruzi, either via a bite wound or intact mucous membranes. Diagnosis of Chagas disease involves serological tests, electrocardiographic findings, and imaging studies. A 58-year-old male patient from Peru with chronic dilated cardiomyopathy underwent evaluation at a tertiary care hospital. Given the uncertain etiology, a comprehensive diagnostic approach was adopted, emphasizing the pivotal role of cardiovascular magnetic resonance imaging and computed tomography angiography in managing chronic cardiomyopathy of Chagas disease. Leveraging these imaging modalities together could augment our ability to evaluate myocardial inflammation and tailor therapeutic strategies accordingly.

Dissimilar Trypanosoma cruzi genotype-specific serological profile assessed by Chagas-Flow ATE IgG1 upon benznidazole etiological treatment of chronic Chagas disease.

The present study aimed to verify the impact of etiological treatment on the genotype-specific serological diagnosis of chronic Chagas disease patients (CH), using the Chagas-Flow ATE IgG1 methodology. For this purpose, a total of 92 serum samples from CH, categorized as Not Treated (NT, n = 32) and Benznidazole-Treated (Bz-T, n = 60), were tested at Study Baseline and 5Years Follow-up. At Study Baseline, all patients have the diagnosis of Chagas disease confirmed by Chagas-Flow ATE IgG1, using the set of attributes ("antigen/serum dilution/cut-off"; "EVI/250/30%"). The genotype-specific serodiagnosis at Study Baseline demonstrated that 96% of patients (44/46) presented a serological profile compatible with TcII genotype infection. At 5Years Follow-up monitoring, NT and Bz-T presented no changes in anti-EVI IgG1 reactivity. However, significant differences were detected in the genotype-specific IgG1 reactivity for Bz-T. The most outstanding shift comprised the anti-amastigote TcVI/(AVI), anti-amastigote TcII/(AII) and anti-epimastigote TcVI/(EVI) reactivities. Regardless no changes in the genotype-specific serology of NT (TcI = 6%; TcII = 94%), distinct T. cruzi genotype-specific sero-classification was detected for Bz-T samples at 5Years Follow-up (TcII = 100%) as compared to Baseline (TcII = 97%; TcVI = 3%). The anti-trypomastigote TcI/(TI) was the attribute accountable for the change in genotype-specific sero-classification. In conclusion, our findings of dissimilar T. cruzi genotype-specific serology upon Bz-treatment re-emphasize the relevance of accomplishing the genotype-specific serodiagnosis during clinical pos-therapeutic management of chronic Chagas disease patients.

Chagas Disease Diagnosis with Trypanosoma cruzi-Exclusive Epitopes in GFP.

Serological tests are critical tools in the fight against infectious disease. They detect antibodies produced during an adaptive immune response against a pathogen with an immunological reagent, whose antibody binding characteristics define the specificity and sensitivity of the assay. While pathogen proteins have conveniently served as reagents, their performance is limited by the natural grouping of specific and non-specific antibody binding sites, epitopes. An attractive solution is to build synthetic proteins that only contains pathogen-specific epitopes, which could theoretically reach 100% specificity. However, the genesis of de novo proteins remains a challenge. To address the uncertainty of producing a synthetic protein, we have repurposed the beta barrel of fluorescent proteins into a receptacle that can receive several epitope sequences without compromising its ability to be expressed. Here, two versions of a multiepitope protein were built using the receptacle that differ by their grouping of epitopes specific to the parasite Trypanosoma cruzi, the causative agent for Chagas disease. An evaluation of their performance as the capture reagent in ELISAs showed near-complete agreement with recommended diagnostic protocols. The results suggest that a single assay could be developed for the diagnosis of Chagas disease and that this approach could be applied to other diseases.

Chagas Disease: Epidemiology, Diagnosis, and Treatment.

This review seeks to describe the updates in the literature - particularly with regards to the epidemiology and diagnosis of Chagas disease. Additionally, this paper describes updates to the antiparasitic treatment for Chagas disease. With regards to changing epidemiology, autochthonous cases are being found within the USA in addition to Latin America. Additionally, there appears to be more intermixing of discrete typing units-meaning, they are not confined to specific geographic regions. Screening for Chagas disease is recommended in persons who lived in areas with endemic Chagas, persons wtih family member diagnosed with Chagas Disease, persons who have lived in homes of natural material in Latin America, and persons with history of kissing bug bites. Treatment for the parasitic infection remains limited to benznidazole and nifurtimox, and the role of these treatments in Chagas cardiomyopathy has not yet been definitively defined. Finally, indications for and management of heart transplant in the setting of Chagas disease are discussed. Use of antiparasitics during chronic chagas disease should be further explored. Additionally, future research identifying other markers of infection would be valuable to defining cure from infection.

The use of rapid diagnostic tests for chronic Chagas disease: An expert meeting report.

Chagas disease, caused by Trypanosoma cruzi, affects millions of people globally and is associated with significant underdiagnosis and undertreatment. Current diagnostic algorithms face challenges in remote regions. We aimed to review the potential of rapid diagnostic tests (RDTs) for screening or diagnosing chronic Chagas disease in endemic areas. An expert panel representing scientific and academic institutions from the Americas convened with the aim of discussing the use of RDTs. The study employed the nominal group technique, gathering insights from diverse experts during a 3-day meeting. Panel discussions covered RDT application, research protocols, and regulatory mechanisms. The results indicate that RDTs play a crucial role in surveillance and screening, although limitations in sensitivity and specificity exist. The expert group recommends standardized protocols, emphasizes the importance of cost-effectiveness assessments, and highlights the need to consider geographic validation. Despite these challenges, RDTs present a promising avenue for improving Chagas disease diagnosis in resource-limited settings. Future research and a collaborative approach are deemed essential for effective implementation.

Trajectory-driven computational analysis for element characterization in Trypanosoma cruzi video microscopy.

Optical microscopy videos enable experts to analyze the motion of several biological elements. Particularly in blood samples infected with Trypanosoma cruzi (T. cruzi), microscopy videos reveal a dynamic scenario where the parasites' motions are conspicuous. While parasites have self-motion, cells are inert and may assume some displacement under dynamic events, such as fluids and microscope focus adjustments. This paper analyzes the trajectory of T. cruzi and blood cells to discriminate between these elements by identifying the following motion patterns: collateral, fluctuating, and pan-tilt-zoom (PTZ). We consider two approaches: i) classification experiments for discrimination between parasites and cells; and ii) clustering experiments to identify the cell motion. We propose the trajectory step dispersion (TSD) descriptor based on standard deviation to characterize these elements, outperforming state-of-the-art descriptors. Our results confirm motion is valuable in discriminating T. cruzi of the cells. Since the parasites perform the collateral motion, their trajectory steps tend to randomness. The cells may assume fluctuating motion following a homogeneous and directional path or PTZ motion with trajectory steps in a restricted area. Thus, our findings may contribute to developing new computational tools focused on trajectory analysis, which can advance the study and medical diagnosis of Chagas disease.

In vitro diagnostic methods of Chagas disease in the clinical laboratory: a scoping review.

Chagas disease (CD), caused by Trypanosoma cruzi, is a global health concern with expanding geographical reach. Despite improved and accessible test methods, diagnosing CD in its various phases remains complex. The existence of clinical scenarios, including immunosuppressed patients, transplant-related CD reactivation, transfusion-associated cases, and orally transmitted acute infections, adds to the diagnostic challenge. No singular gold standard test exists for all phases, and recommendations from PAHO and the CDC advocate for the use of two serological methods for chronic CD diagnosis, while molecular methods or direct parasite detection are suggested for the acute phase. Given the complexity in the diagnostic landscape of CD, the goal of this scoping review is to characterize available diagnostic tests for CD in the clinical laboratory. A literature search in PubMed was conducted on studies related to In vitro diagnosis (IVD) in humans published in English, Spanish, or Portuguese language as of 28 August 2023, and extended backward with no predefined time frame. Studies underwent title and abstract screening, followed by full-text review. Studies included were classified based on the diagnostic method used. Test methods were grouped as serological, molecular, and other methods. Performance, availability, and regulatory status were also characterized. Out of 85 studies included in the final review, 115 different tests were identified. These tests comprised 89 serological test types, 21 molecular test types, and 5 other test methods. Predominant serological tests included ELISA (38 studies, 44.70%), Rapid tests (19 studies, 22.35%), and chemiluminescence (10 studies, 11.76%). Among molecular tests, Polymerase Chain Reaction (PCR) assays were notable. Twenty-eight tests were approved globally for IVD or donor testing, all being serological methods. Molecular assays lacked approval for IVD in the United States, with only European and Colombian regulatory acceptance. Serological tests, specifically ELISAs, remain the most used and commercially available diagnostic methods. This makes sense considering that most Chagas disease diagnoses occur in the chronic phase and that the WHO gold standard relies on 2 serological tests to establish the diagnosis of chronic Chagas. ELISAs are feasible and relatively low-cost, with good performance with sensitivities ranging between 77.4% and 100%, and with specificities ranging between 84.2% and 100%. Molecular methods allow the detection of specific variants but rely on the parasite's presence, which limits their utility to parasitemia levels. Depending on the PCR method and the phase of the disease, the sensitivity ranged from 58.88 to 100% while the mean specificity ranged from 68.8% to 100%. Despite their performance, molecular testing remains mostly unavailable for IVD use. Only 3 molecular tests are approved for IVD, which are available only in Europe. Six commercial serological assays approved by the FDA are available for blood and organ donor screening. Currently, there are no guidelines for testing CD oral outbreaks. Although more evidence is needed on how testing methods should be used in special clinical scenarios, a comprehensive approach of clinical assessment and diagnostics tests, including not IVD methods, is required for an accurate CD diagnosis.

Spatio-temporal distribution of hospitalizations for chronic Chagas disease and risk factors associated with in-hospital mortality and surgical intervention in Chile.

Chagas disease (CD) is a neglected parasitic zoonotic disease that affects over 6 million people worldwide. We conducted a retrospective study to analyze the spatiotemporal trends and risk factors for hospitalization rates of CD with cardiac and digestive diagnoses in Chile. We used the Mann-Kendall analysis for temporal trends, Global Moran's Index, and Local Indicators of Spatial Association to identify spatial autocorrelation, and regression models to determine the risk factors associated with in-hospital mortality and surgical intervention. Between 2010 and 2020, a total of 654 hospitalizations were reported, corresponding to 527 individuals. The hospitalization rate steadily decreased over the years (t = -0.636; p = 0.009). The Global Moran's I for the study period showed a positive spatial autocorrelation for hospitalization municipality and for residence municipality of CD patients (I = 0.25, p<0.001 and I = 0.45, p<0.001 respectively), indicating a clustering of hospitalizations in northern municipalities. The most frequent diagnosis was a chronic CD with digestive system involvement (55.8%) followed by a chronic CD with heart involvement (44.2%). The highest percentage of hospital discharges was observed among males (56.9%) and in the 60-79 age group (52.7%). In-hospital mortality risk was higher with increasing age (OR = 1.04), and in patients with cardiac involvement (OR = 2.3), whereas factors associated with the risk of undergoing a surgical intervention were sex (OR = 1.6) and diagnosis of CD with digestive involvement (OR = 4.4). The findings of this study indicate that CD is still a significant public health burden in Chile. Efforts should focus on improving access to timely diagnoses and treatment, reducing disease progression and hospitalization burden, and supporting clinicians in preventing complications and deaths.

Machine learning for predicting Chagas disease infection in rural areas of Brazil.

Chagas disease is a severe parasitic illness that is prevalent in Latin America and often goes unaddressed. Early detection and treatment are critical in preventing the progression of the illness and its associated life-threatening complications. In recent years, machine learning algorithms have emerged as powerful tools for disease prediction and diagnosis. In this study, we developed machine learning algorithms to predict the risk of Chagas disease based on five general factors: age, gender, history of living in a mud or wooden house, history of being bitten by a triatomine bug, and family history of Chagas disease. We analyzed data from the Retrovirus Epidemiology Donor Study (REDS) to train five popular machine learning algorithms. The sample comprised 2,006 patients, divided into 75% for training and 25% for testing algorithm performance. We evaluated the model performance using precision, recall, and AUC-ROC metrics. The Adaboost algorithm yielded an AUC-ROC of 0.772, a precision of 0.199, and a recall of 0.612. We simulated the decision boundary using various thresholds and observed that in this dataset a threshold of 0.45 resulted in a 100% recall. This finding suggests that employing such a threshold could potentially save 22.5% of the cost associated with mass testing of Chagas disease. Our findings highlight the potential of applying machine learning to improve the sensitivity and effectiveness of Chagas disease diagnosis and prevention. Furthermore, we emphasize the importance of integrating socio-demographic and environmental factors into neglected disease prediction models to enhance their performance.

Comparative evaluation of four rapid diagnostic tests that detect human Trypanosoma cruzi-specific antibodies to support diagnosis of Chagas Disease in urban population of Argentina.

Chagas disease (CD), caused by the parasite Trypanosoma cruzi, is the most important endemic anthropozoonosis in Argentina. Since 2010, the World Health Organization has highlighted the urgent need to validate diagnostic systems that allow rapid detection of T. cruzi, infection in primary healthcare centers. Serological rapid diagnostic tests (RDTs) for T. cruzi, infection could be used to improve case management, as RDTs do not require specialized laboratories or highly trained staff to use them. We aimed to generate unbiased performance data of RDTs in Argentina, to evaluate their usefulness for improving T. cruzi, diagnosis rates. This is a retrospective, laboratory-based, diagnostic evaluation study to estimate the clinical sensitivity/specificity of four commercially available RDTs for T. cruzi, using the Chagas disease diagnostic algorithm currently used in Argentina as the reference standard. In total, 400 serum samples were tested, 200 from individuals with chronic T. cruzi infection and 200 from individuals not infected with T. cruzi. All results were registered as the agreement of at least two operators who were blinded to the reference standard results. The sensitivity estimates ranged from 92.5-100% (95% confidence interval (CI) lower bound 87.9-98.2%); for specificity, the range was 76-96% (95% CI lower bound 69.5-92.3%). Most RDTs evaluated showed performances comparable with the reference standard method, showing almost perfect concordance (Kappa 0.76-0.92). Our study demonstrates that, under controlled laboratory conditions, commercially available RDTs for CD have a performance comparable to the Argentinian diagnostic algorithm, which is based on laboratory-based serological tests. For the next stage of our work, the RDTs will be evaluated in real-world settings.

Impact of an online course on enhancing the diagnosis of Chagas disease in Latin America.

Chagas disease poses a public health problem in Latin America, and the electrocardiogram is a crucial tool in the diagnosis and monitoring of this pathology. In this context, the aim of this study was to quantify the change in the ability to detect electrocardiographic patterns among healthcare professionals after completing a virtual course. An asynchronous virtual course with seven pre-recorded classes was conducted. Participants answered the same questionnaire at the beginning and end of the training. Based on these responses, pre and post-test results for each participant were compared. The study included 1656 participants from 21 countries; 87.9% were physicians, 5.2% nurses, 4.1% technicians, and 2.8% medical students. Initially, 3.1% answered at least 50% of the pre-test questions correctly, a proportion that increased to 50.4% after the course (p=0.001). Regardless of their baseline characteristics, 82.1% of course attendees improved their answers after completing the course. The implementation of an asynchronous online course on electrocardiography in Chagas disease enhanced the skills of both medical and non-medical personnel to recognize this condition.

Usefulness of polymerase chain reaction tests in Chagas disease studies.

The Polymerase Chain Reaction (PCR) test is a highly sensitive, specific, and rapid diagnostic tool for Chagas disease. Chagas disease is caused by the protozoan flagellate Trypanosoma cruzi and is endemic to the Americas. While conventional serological methods are still used in the diagnosis of Chagas disease, they are being gradually replaced by molecular methods like PCR. PCR can detect the parasite's DNA in blood or tissue samples from humans and animals, including asymptomatic infections and animal reservoirs. In a study conducted on a colony of New World monkeys, PCR analysis was found to be superior to conventional screening tools for trypanosome infection, although false negatives can still occur. In clinical studies, PCR has been used to assess the effectiveness of Nifurtimox and Benznidazole in treating acute and chronic Chagas patients. However, the presence of low-grade and intermittent parasitemia in peripheral blood, even in the absence of treatment, renders PCR an unreliable test for evaluating successful treatment. Based on this limiting factor, among others, we do not believe that PCR is an appropriate gold standard test for Chagas in clinical and preclinical studies. Other diagnostic methods, such as serological and biomarker tests, should be used in conjunction with PCR techniques for more accurate diagnosis of Chagas.

Chagas Disease and Leishmaniasis, Sympatric Zoonoses Present in Human from Rural Communities of Venezuela.

Trypanosoma cruzi and Leishmania spp. coexist in several endemic areas, and there are few studies of Chagas disease and leishmaniasis coinfection worldwide; for this reason, the objective of this work was to determine the Chagas disease and leishmaniasis coinfection in several rural communities co-endemic for these diseases. A total of 1107 human samples from six co-endemic rural communities of Cojedes state, Venezuela, were analyzed. Serum samples were evaluated by ELISA, indirect hemagglutination, and indirect immunofluorescence for Chagas disease diagnosis, and individuals were evaluated for leishmaniasis by leishmanin skin test (LST). Approximately, 30% of the individuals were also analyzed by PCR (blood clot samples) for T. cruzi and for Leishmania spp. The 14.7% of the individuals were positive to Trypanosoma cruzi infection by serology, and 25.8% were positive to Leishmania spp. current or past infection by LST. Among the group with PCR results, 7.8% were positive for T. cruzi, and 9.4% for Leishmania spp. The coinfection T. cruzi/Leishmania spp. was 6.5%. The T. cruzi DTUs of the positive blood clot samples were TcI, revealed using the molecular markers: (i) intergenic region of the miniexon, (ii) D7 divergent domain of the 24Sα rDNA, (iii) size-variable domain of the 18S rDNA, and (iv) hsp60-PCR-RFLP (EcoRV). The Leishmania species identified were L. (Leishmania) mexicana and L. (Viannia) braziliensis. A high prevalence was found for T. cruzi and Leishmania spp. single and coinfections in almost all communities studied, being these results of relevance for the implementation of control programs in co-endemic areas.

Chagas cardiomyopathy in Boston, Massachusetts: Identifying disease and improving management after community and hospital-based screening.

Limited data exist regarding cardiac manifestations of Chagas disease in migrants living in non-endemic regions. A retrospective cohort analysis of 109 patients with Chagas disease seen at Boston Medical Center (BMC) between January 2016 and January 2023 was performed. Patients were identified by screening and testing migrants from endemic regions at a community health center and BMC. Demographic, laboratory, and cardiac evaluation data were collected. Mean age of the 109 patients was 43 years (range 19-76); 61% were female. 79% (86/109) were diagnosed with Chagas disease via screening and 21% (23/109) were tested given symptoms or electrocardiogram abnormalities. Common symptoms included palpitations (25%, 27/109) and chest pain (17%, 18/109); 52% (57/109) were asymptomatic. Right bundle branch block (19%, 19/102), T-wave changes (18%, 18/102), and left anterior fascicular block (11%, 11/102) were the most common electrocardiogram abnormalities; 51% (52/102) had normal electrocardiograms. Cardiomyopathy stage was ascertained in 94 of 109 patients: 51% (48/94) were indeterminate stage A and 49% (46/94) had cardiac structural disease (stages B1-D). Clinical findings that required clinical intervention or change in management were found in 23% (25/109), and included cardiomyopathy, apical hypokinesis/aneurysm, stroke, atrial or ventricular arrhythmias, and apical thrombus. These data show high rates of cardiac complications in a cohort of migrants living with Chagas disease in a non-endemic setting. We demonstrate that Chagas disease diagnosis prompts cardiac evaluation which often identifies actionable cardiac disease and provides opportunities for prevention and treatment.

Characterization of Novel Trypanosoma cruzi-Specific Antigen with Potential Use in the Diagnosis of Chagas Disease.

Chagas disease is caused by the parasite Trypanosoma cruzi. In humans, it evolves into a chronic disease, eventually resulting in cardiac, digestive, and/or neurological disorders. In the present study, we characterized a novel T. cruzi antigen named Tc323 (TcCLB.504087.20), recognized by a single-chain monoclonal antibody (scFv 6B6) isolated from the B cells of patients with cardiomyopathy related to chronic Chagas disease. Tc323, a ~323 kDa protein, is an uncharacterized protein showing putative quinoprotein alcohol dehydrogenase-like domains. A computational molecular docking study revealed that the scFv 6B6 binds to an internal domain of Tc323. Immunofluorescence microscopy and Western Blot showed that Tc323 is expressed in the main developmental forms of T. cruzi, localized intracellularly and exhibiting a membrane-associated pattern. According to phylogenetic analysis, Tc323 is highly conserved throughout evolution in all the lineages of T. cruzi so far identified, but it is absent in Leishmania spp. and Trypanosoma brucei. Most interestingly, only plasma samples from patients infected with T. cruzi and those with mixed infection with Leishmania spp. reacted against Tc323. Collectively, our findings demonstrate that Tc323 is a promising candidate for the differential serodiagnosis of chronic Chagas disease in areas where T. cruzi and Leishmania spp. infections coexist.