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Chaves LF, Meyers AC, Hodo CL, Sanders JP, Curtis-Robles R, Hamer GL, Hamer SA. Trypanosoma cruzi infection in dogs along the US-Mexico border: R 0 changes with vector species composition. Epidemics 2023; 45:100723. [PMID: 37935075 DOI: 10.1016/j.epidem.2023.100723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 07/05/2023] [Accepted: 10/26/2023] [Indexed: 11/09/2023] Open
Abstract
Infection with Trypanosoma cruzi, etiological agent of Chagas disease, is common in US government working dogs along the US-Mexico border. This 3145 km long border comprises four states: Texas (TX), New Mexico (NM), Arizona (AZ) and California (CA) with diverse ecosystems and several triatomine (a.k.a., kissing bug) species, primary vectors of T. cruzi in this region. The kissing bug (Heteroptera: Reduviidae) community ranging from CA to TX includes Triatoma protracta (Uhler), Triatoma recurva (Stål) and Triatoma rubida (Uhler) and becomes dominated by Triatoma gerstaeckeri Stål in TX. Here, we ask if T. cruzi infection dynamics in dogs varies along this border region, potentially reflecting changes in vector species and their vectorial capacity. Using reversible catalytic models of infection, where seropositivity can be lost, we estimated an R0 (Estimate ± S.E.) of 1.192 ± 0.084 for TX and NM. In contrast, seropositivity decayed to zero as dogs aged in AZ and CA. These results suggest that dogs are likely infected by T. cruzi during their training in western TX, with a force of infection large enough for keeping R0 above 1, i.e., the disease endemically established, in TX and NM. In AZ and CA, a lower force of infection, probably associated with different vector species communities and associated vectorial capacity and/or different lineages of T. cruzi, results in dogs decreasing their seropositivity with age.
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Affiliation(s)
- Luis Fernando Chaves
- Department of Environmental and Occupational Health, School of Public Health, Indiana University, Bloomington IN 47405, USA.
| | - Alyssa C Meyers
- Department of Veterinary Integrative Bioscienes, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA; Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| | - Carolyn L Hodo
- Department of Veterinary Integrative Bioscienes, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA; Department of Comparative Medicine, Keeling Center for Comparative Medicine and Research, The University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA
| | - John P Sanders
- Office of Health Security, US Department of Homeland Security, Washington, DC 20528, USA
| | - Rachel Curtis-Robles
- Department of Veterinary Integrative Bioscienes, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Gabriel L Hamer
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Sarah A Hamer
- Department of Veterinary Integrative Bioscienes, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
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2
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Pinto J, Skjefte M, Alonso-Padilla J, Lozano Beltran DF, Pinto LV, Casellas A, Arteaga Terrazas ME, Toledo Galindo KA, Challapa Quechover R, Escobar Caballero M, Perez Salinas A, Castellón Jimenez M, Sanz S, Gascón J, Torrico F, Pinazo MJ. Five-year serological and clinical evolution of chronic Chagas disease patients in Cochabamba, Bolivia. PLoS Negl Trop Dis 2023; 17:e0011498. [PMID: 38157376 PMCID: PMC10756508 DOI: 10.1371/journal.pntd.0011498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024] Open
Abstract
BACKGROUND Chagas disease, caused by the parasite Trypanosoma cruzi, is a neglected infectious disease that exerts the highest public health burden in the Americas. There are two anti-parasitic drugs approved for its treatment-benznidazole and nifurtimox-but the absence of biomarkers to early assess treatment efficacy hinders patients´ follow-up. METHODOLOGY/PRINCIPAL FINDINGS We conducted a longitudinal, observational study among a cohort of 106 chronically T. cruzi-infected patients in Cochabamba (Bolivia) who completed the recommended treatment of benznidazole. Participants were followed-up for five years, in which we collected clinical and serological data, including yearly electrocardiograms and optical density readouts from two ELISAs (total and recombinant antigens). Descriptive and statistical analyses were performed to understand trends in data, as well as the relationship between clinical symptoms and serological evolution after treatment. Our results showed that both ELISAs documented average declines up to year three and slight inclines for the following two years. The recorded clinical parameters indicated that most patients did not have any significant changes to their cardiac or digestive symptoms after treatment, at least in the timeframe under investigation, while a small percentage demonstrated either a regression or progression in symptoms. Only one participant met the "cure criterion" of a negative serological readout for both ELISAs by the final year. CONCLUSIONS/SIGNIFICANCE The study confirms that follow-up of benznidazole-treated T. cruzi-infected patients should be longer than five years to determine, with current tools, if they are cured. In terms of serological evolution, the single use of a total antigen ELISA might be a more reliable measure and suffice to address infection status, at least in the region of Bolivia where the study was done. Additional work is needed to develop a test-of-cure for an early assessment of drugs´ efficacy with the aim of improving case management protocols.
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Affiliation(s)
- Jimy Pinto
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia
| | - Malia Skjefte
- Harvard TH Chan School of Public Health, Department of Global Health and Population, Boston, Massachusetts, United States of America
| | - Julio Alonso-Padilla
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, Barcelona, Spain
- CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC, ISCIII), Madrid, Spain
| | - Daniel Franz Lozano Beltran
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia
- Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Lilian Victoria Pinto
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia
| | - Aina Casellas
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, Barcelona, Spain
| | - Mery Elena Arteaga Terrazas
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia
| | | | - Roxana Challapa Quechover
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia
| | - María Escobar Caballero
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia
| | - Alejandra Perez Salinas
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia
| | - Mario Castellón Jimenez
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia
| | - Sergi Sanz
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, Barcelona, Spain
| | - Joaquim Gascón
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, Barcelona, Spain
- CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC, ISCIII), Madrid, Spain
| | - Faustino Torrico
- Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia
- Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - María Jesús Pinazo
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, Barcelona, Spain
- CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC, ISCIII), Madrid, Spain
- Drugs for Neglected Diseases Initiative (DNDi), Geneve, Switzerland
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3
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Olivo Freites C, Sy H, Gharamti A, Higuita NIA, Franco-Paredes C, Suárez JA, Henao-Martínez AF. Chronic Chagas Disease-the Potential Role of Reinfections in Cardiomyopathy Pathogenesis. Curr Heart Fail Rep 2022; 19:279-289. [PMID: 35951245 DOI: 10.1007/s11897-022-00568-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/11/2022] [Indexed: 10/15/2022]
Abstract
PURPOSE OF THE REVIEW Chagas disease is a neglected anthropozoonosis of global importance with significant cardiovascular-associated mortality. This review focuses on the Trypanosoma cruzi reinfections' role in chronic Chagas cardiomyopathy pathogenesis. We discuss and summarize the available data related to pathology, pathogenesis, diagnosis, and treatment of reinfections. RECENT FINDINGS Reinfections influence the genetic and regional diversity of T. cruzi, tissue tropism, modulation of the host's immune system response, clinical manifestations, the risk for congenital infections, differences in diagnostics performances, response to antiparasitic therapy, and the natural history of the disease. Animal models suggest that reinfections lead to worse outcomes and increased mortality, while other studies showed an association between reinfections and lower parasitemia levels and subsequent infection protection. In some regions, the human risk of reinfections is 14% at 5 years. Evidence has shown that higher anti-T. cruzi antibodies are correlated with an increased rate of cardiomyopathy and death, suggesting that a higher parasite exposure related to reinfections may lead to worse outcomes. Based on the existing literature, reinfections may play a role in developing and exacerbating chronic Chagas cardiomyopathy and are linked to worse outcomes. Control efforts should be redirected to interventions that address structural poverty for the successful and sustainable prevention of Chagas disease.
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Affiliation(s)
- Christian Olivo Freites
- Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Hendrik Sy
- Internal Medicine Department, Mount Sinai Health System, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Amal Gharamti
- Internal Medicine Department, Yale-Waterbury Hospital, Yale School of Medicine, New Haven, CT, USA
| | | | | | - José Antonio Suárez
- Clinical Research Department, Investigador SNI Senacyt Panamá, Instituto Conmemorativo Gorgas de Estudios de La Salud, Panamá City, Republic of Panama
| | - Andrés F Henao-Martínez
- Department of Medicine, University of Colorado Anschutz Medical Campus, 12700 E. 19th Avenue, Mail Stop B168, Aurora, CO, USA.
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4
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Crespillo-Andújar C, Comeche B, Hamer DH, Arevalo-Rodriguez I, Alvarez-Díaz N, Zamora J, Pérez-Molina JA. Use of benznidazole to treat chronic Chagas disease: An updated systematic review with a meta-analysis. PLoS Negl Trop Dis 2022; 16:e0010386. [PMID: 35576215 PMCID: PMC9135346 DOI: 10.1371/journal.pntd.0010386] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 05/26/2022] [Accepted: 04/01/2022] [Indexed: 11/18/2022] Open
Abstract
Background Approximately 6 million people worldwide are affected by Chagas disease, with many in the chronic phase of the disease (CCD). It is crucial to evaluate the effectiveness of benznidazole for CCD treatment. Methods/Principal findings We updated a meta-analysis published in 2009 up to February 2021, including controlled trials (RCT) and prospective observational studies (OBS) that compared benznidazole vs placebo/no-treatment (P/nT). Main outcomes evaluated were clinical progression (CP) and seroreversion with subgroup analysis performed according to study design and participants’ age. Parasitological response and safety were also described. We identified 879 articles and selected nine for inclusion (corresponding to eight studies). After adding the nine articles from the previous meta-analysis, 17 studies were analyzed corresponding to 6640 patients. The odds ratio (OR) for seroreversion in children treated with benznidazole vs P/nT was 38.3 (95%CI: 10.7–137) and 34.9 (95%CI: 1.96–624.09) in RCT and OBS, respectively. In adults the OR for seroreversion in OBS was 17.1 (95%CI: 2.3–129.1). CP was only evaluated in adults, where benznidazole did not demonstrate a beneficial effect: OR 0.93 (95%CI: 0.8–1.1) and OR 0.49 (95%CI:0.2–1.2) for RCT and OBS, respectively. Most outcomes were deemed to have a low level of certainty, except for the beneficial effect in children and the low efficacy in adults (moderate certainty). Conclusions Benznidazole should be recommended for CCD in children, though this is only based on serological response and a moderate grade of evidence, while in adults benznidazole efficacy remains uncertain. More data on clinical efficacy of benznidazole in CCD is needed in both children and adults. Chagas disease is a neglected parasitic disease, endemic in Latin America, where it poses a public health problem. Moreover, thanks to population movements, its presence has significantly increased in non-endemic areas, where it has high rates of under-diagnosis. The only two treatments currently available (benznidazole, generally the first choice, and nifurtimox) date from the 1960s and are poorly tolerated. Moreover, there is much uncertainty about their indication, dosage and benefits, especially in chronically infected adult populations. For this reason, we have update a meta-analysis published in 2009 on the effectiveness of benznidazole in chronic Chagas disease, analyzing data from 17 studies involving 6,640 patients. In the pediatric population the indication is well established thanks to some clinical trials carried out in the 1990s and the accumulated clinical experience so far. Most of the recent studies have been performed in adult populations; however, they provide low or very low certainty on the effectiveness of benznidazole except for patients with established cardiomyopathy, where benznidazole didn´t demonstrated benefit. We find that data on the treatment of indeterminate chronic infection are insufficient. Since no new drugs are expected in the near future, it would be desirable to launch trials with clinical outcomes and long follow-up periods to evaluate the efficacy of current drugs for the treatment of the indeterminate chronic Chagas disease.
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Affiliation(s)
- Clara Crespillo-Andújar
- National Referral Centre for Tropical Diseases, Infectious Diseases Department, Hospital Universitario Ramón y Cajal, Madrid, Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- CIBER de Enfermedades infecciosas, Instituto de Salud Carlos III, Madrid, Spain
| | - Belén Comeche
- National Referral Centre for Tropical Diseases, Infectious Diseases Department, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Davidson H. Hamer
- Department of Global Health, Boston University School of Public Health, Boston, Massachusetts, United States of America
- Department of Medicine, Section of Infectious Diseases, Boston University School of Medicine, Boston, Massachusetts, United States of America
- National Emerging Infectious Diseases Laboratory, Boston University, Boston, Massachusetts, United States of America
| | - Ingrid Arevalo-Rodriguez
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Clinical Biostatistics Unit, Hospital Universitario Ramón y Cajal, Madrid, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | | | - Javier Zamora
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Clinical Biostatistics Unit, Hospital Universitario Ramón y Cajal, Madrid, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Institute of Metabolism and Systems Research, WHO Collaborating Center for Global Women’s Health, University of Birmingham, Birmingham, United Kingdom
| | - José A. Pérez-Molina
- National Referral Centre for Tropical Diseases, Infectious Diseases Department, Hospital Universitario Ramón y Cajal, Madrid, Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- CIBER de Enfermedades infecciosas, Instituto de Salud Carlos III, Madrid, Spain
- * E-mail:
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5
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Lascano F, García Bournissen F, Altcheh J. Review of pharmacological options for the treatment of Chagas disease. Br J Clin Pharmacol 2022; 88:383-402. [PMID: 33314266 DOI: 10.1111/bcp.14700] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/09/2020] [Accepted: 12/02/2020] [Indexed: 12/20/2022] Open
Abstract
Chagas disease (CD) is a worldwide problem, with over 8 million people infected in both rural and urban areas. CD was first described over a century ago, but only two drugs are currently available for CD treatment: benznidazole (BZN) and nifurtimox (NF). Treating CD-infected patients, especially children and women of reproductive age, is vital in order to prevent long-term sequelae, such as heart and gastrointestinal dysfunction, but this aim is still far from being accomplished. Currently, the strongest data to support benefit-risk considerations come from trials in children. Treatment response biomarkers need further development as serology is being questioned as the best method to assess treatment response. This article is a narrative review on the pharmacology of drugs for CD, particularly BZN and NF. Data on drug biopharmaceutical characteristics, safety and efficacy of both drugs are summarized from a clinical perspective. Current data on alternative compounds under evaluation for CD treatment, and new possible treatment response biomarkers are also discussed. Early diagnosis and treatment of CD, especially in paediatric patients, is vital for an effective and safe use of the available drugs (i.e. BZN and NF). New biomarkers for CD are urgently needed for the diagnosis and evaluation of treatment efficacy, and to guide efforts from academia and pharmaceutical companies to accelerate the process of new drug development.
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Affiliation(s)
- Fernanda Lascano
- Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas (IMIPP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Gobierno de la Ciudad de la Nación Argentina, Buenos Aires, Argentina.,Servicio de Parasitología y Chagas, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Facundo García Bournissen
- Division of Pediatric Clinical Pharmacology, Department of Pediatrics, Schulich School of Medicine & Dentistry, University of Western Ontario, Canada
| | - Jaime Altcheh
- Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas (IMIPP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Gobierno de la Ciudad de la Nación Argentina, Buenos Aires, Argentina.,Servicio de Parasitología y Chagas, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
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6
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Vizcaya D, Grossmann U, Kleinjung F, Zhang R, Suzart-Woischnik K, Seu S, Ramirez T, Colmegna L, Ledesma O. Serological response to nifurtimox in adult patients with chronic Chagas disease: An observational comparative study in Argentina. PLoS Negl Trop Dis 2021; 15:e0009801. [PMID: 34606501 PMCID: PMC8489720 DOI: 10.1371/journal.pntd.0009801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 09/09/2021] [Indexed: 11/18/2022] Open
Abstract
Nifurtimox is indicated in Chagas disease but determining its effectiveness in chronic disease is hindered by the length of time needed to demonstrate negative serological conversion. We manually reviewed long-term follow-up data from hospital records of patients with chronic Chagas disease (N = 1,497) in Argentina diagnosed during 1967-1980. All patients were aged ≥18 years at diagnosis and were either treated with nifurtimox (n = 968) or received no antitrypanosomal treatment (n = 529). The primary endpoint was negative seroconversion (the "event"), defined as a change from positive to negative in the serological or parasitological laboratory test used at diagnosis. Time to event was from baseline visit to date of endpoint event or censoring. The effectiveness of nifurtimox versus no treatment was estimated with Cox proportional hazard regression using propensity scores with overlap weights to calculate the hazard ratio and 95% confidence interval. The nifurtimox group was younger than the untreated group (mean, 32.4 vs. 40.3 years), with proportionally fewer females (47.9% vs. 60.1%), and proportionally more of the nifurtimox group than the untreated group had clinical signs and symptoms of Chagas disease at diagnosis (28.9% vs. 14.0%). Median maximum daily dose of nifurtimox was 8.0 mg/kg/day (interquartile range [IQR]: 8.0-9.0) and median treatment duration was 44 days (IQR: 1-90). Median time to event was 2.1 years (IQR: 1.0-4.5) for nifurtimox-treated and 2.4 years (IQR: 1.0-4.2) for untreated patients. Accounting for potential confounders, the estimated hazard ratio (95% confidence interval) for negative seroconversion was 2.22 (1.61-3.07) favoring nifurtimox. Variable treatment regimens and follow-up duration, and an uncommonly high rate of spontaneous negative seroconversion, complicate interpretation of this epidemiological study, but with the longest follow-up and largest cohort analyzed to date it lends weight to the benefit of nifurtimox in adults with chronic Chagas disease. Trial registration: The study protocol was registered at ClinicalTrials.gov: NCT03784391.
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Affiliation(s)
- David Vizcaya
- Bayer Pharmaceuticals, Sant Joan Despi, Spain
- * E-mail:
| | | | | | | | | | - Sandra Seu
- Centro de Chagas y Patología Regional, Hospital Independencia, Santiago del Estero, Argentina
| | - Teresa Ramirez
- Centro de Chagas y Patología Regional, Hospital Independencia, Santiago del Estero, Argentina
| | | | - Oscar Ledesma
- Centro de Chagas y Patología Regional, Hospital Independencia, Santiago del Estero, Argentina
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7
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Teixeira AAR, Carnero LR, Kuramoto A, Tang FHF, Gomes CH, Pereira NB, de Oliveira LC, Garrini R, Monteiro JS, Setubal JC, Sabino EC, Pasqualini R, Colli W, Arap W, Alves MJM, Cunha-Neto E, Giordano RJ. A refined genome phage display methodology delineates the human antibody response in patients with Chagas disease. iScience 2021; 24:102540. [PMID: 34142048 PMCID: PMC8185243 DOI: 10.1016/j.isci.2021.102540] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 03/30/2021] [Accepted: 05/12/2021] [Indexed: 12/23/2022] Open
Abstract
Large-scale mapping of antigens and epitopes is pivotal for developing immunotherapies but challenging, especially for eukaryotic pathogens, owing to their large genomes. Here, we developed an integrated platform for genome phage display (gPhage) to show that unbiased libraries of the eukaryotic parasite Trypanosoma cruzi enable the identification of thousands of antigens recognized by serum samples from patients with Chagas disease. Because most of these antigens are hypothetical proteins, gPhage provides evidence of their expression during infection. We built and validated a comprehensive map of Chagas disease antibody response to show how linear and putative conformation epitopes, many rich in repetitive elements, allow the parasite to evade a buildup of neutralizing antibodies directed against protein domains that mediate infection pathogenesis. Thus, the gPhage platform is a reproducible and effective tool for rapid simultaneous identification of epitopes and antigens, not only in Chagas disease but perhaps also in globally emerging/reemerging acute pathogens. Genomic shotgun phage display (gPhage) of eukaryotes is feasible and promising. gPhage allows rapid antigen ID and epitope mapping, including 3D structures. Conformation epitopes can be identified and validated by using the gPhage platform. Most Chagas disease antigens are hypothetical proteins rich in repetitive elements.
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Affiliation(s)
- André Azevedo Reis Teixeira
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Luis Rodriguez Carnero
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Andréia Kuramoto
- Heart Institute (InCor), University of São Paulo School of Medicine, São Paulo, SP, 05403-000, Brazil
| | - Fenny Hui Fen Tang
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil.,Division of Cancer Biology, Department of Radiation Oncology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA
| | - Carlos Hernique Gomes
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Natalia Bueno Pereira
- Heart Institute (InCor), University of São Paulo School of Medicine, São Paulo, SP, 05403-000, Brazil
| | - Léa Campos de Oliveira
- Institute of Tropical Medicine, University of São Paulo School of Medicine, São Paulo, SP, 05403-000, Brazil
| | - Regina Garrini
- Institute of Tropical Medicine, University of São Paulo School of Medicine, São Paulo, SP, 05403-000, Brazil
| | - Jhonatas Sirino Monteiro
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - João Carlos Setubal
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Ester Cerdeira Sabino
- Institute of Tropical Medicine, University of São Paulo School of Medicine, São Paulo, SP, 05403-000, Brazil
| | - Renata Pasqualini
- Rutgers Cancer Institute of New Jersey, Newark, NJ 07103, USA.,Division of Cancer Biology, Department of Radiation Oncology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA
| | - Walter Colli
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Wadih Arap
- Rutgers Cancer Institute of New Jersey, Newark, NJ 07103, USA.,Division of Hematology/Oncology, Department of Medicine, Rutgers New Jersey Medical School, Newark, NJ 07103, USA
| | - Maria Júlia Manso Alves
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Edécio Cunha-Neto
- Heart Institute (InCor), University of São Paulo School of Medicine, São Paulo, SP, 05403-000, Brazil.,Division of Clinical Immunology and Allergy, University of São Paulo School of Medicine, São Paulo, SP 01246-903, Brazil.,Institute for Investigation in Immunology (iii), INCT, São Paulo, SP, Brazil
| | - Ricardo José Giordano
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil.,Institute for Investigation in Immunology (iii), INCT, São Paulo, SP, Brazil
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8
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Hasslocher-Moreno AM, Saraiva RM, Sangenis LH, Xavier SS, de Sousa AS, Costa AR, de Holanda MT, Veloso HH, Mendes FS, Costa FA, Boia MN, Brasil PE, Carneiro FM, da Silva GM, Mediano MF. Benznidazole decreases the risk of chronic Chagas disease progression and cardiovascular events: A long-term follow up study. EClinicalMedicine 2021; 31:100694. [PMID: 33554085 PMCID: PMC7846661 DOI: 10.1016/j.eclinm.2020.100694] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/24/2020] [Accepted: 12/07/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Chagas disease (CD) remains an important endemic disease in Latin America. However, CD became globalized in recent decades. The majority of the chronically infected individuals did not receive etiologic treatment for several reasons, among them the most conspicuous is the lack of access to diagnosis. The impact of trypanocidal treatment on CD chronic phase, without cardiac involvement (indeterminate form ICF), is yet to be determined. We aimed to evaluate the effect of trypanocidal treatment with benznidazole (BZN) on the rate of progression to Chagas heart disease in patients with ICF. METHODS This is a retrospective cohort observational study including patients with ICF treated with BZN and compared to a group of non-treated patients matched for age, sex, region of origin, and the year of cohort entry. We reviewed the medical charts of all patients followed from May 1987 to June 2020 at the outpatient center of the Evandro Chagas National Institute of Infectious Diseases (INI) of the Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil. Patients' follow-up included at least one annual medical visit and one annual electrocardiogram (ECG). Echocardiographic exams were performed at baseline and during the follow-up. Disease progression from ICF to cardiac form was defined by changes in baseline ECG. Cumulative incidence and the incidence rate were described in the incidence analysis. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for the association between BZN and CD progression, cardiovascular events or death. FINDINGS One hundred and fourteen treated patients met the study inclusion criteria. A comparison group of 114 non-treated patients matched for age, sex, region of origin, and the year of cohort entry was also included, totalizing 228 patients. Most patients included in the study were male (70.2%), and their mean age was 31.3 (+7.4) years. Over a median follow-up of 15.1 years (ranging from 1.0 to 32.4), the cumulative CD progression incidence in treated patients was 7.9% vs. 21.1% in the non-treated group (p = 0.04) and the CD progression rate was 0.49 per 1.000 patients/year in treated patients vs. 1.10 per 1.000 patients/year for non-treated patients (p = 0.02). BZN treatment was associated with a decreased risk of CD progression in both unadjusted (HR 0.46; 95%CI 0.21 to 0.98) and adjusted (HR 0.43; 95%CI 0.19 to 0.96) models and with a decreased risk of occurrence of the composite of cardiovascular events only in the adjusted (HR 0.15; 95%CI 0.03 to 0.80) model. No association was observed between BZN treatment and mortality. INTERPRETATION In a long-term follow-up, BZN treatment was associated with a decreased incidence of CD progression from ICF to the cardiac form and also with a decreased risk of cardiovascular events. Therefore, our results indicate that BZN treatment for CD patients with ICF should be implemented into clinical practice.
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Affiliation(s)
- Alejandro M. Hasslocher-Moreno
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
- Corresponding author.
| | - Roberto M. Saraiva
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Luiz H.C. Sangenis
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Sergio S. Xavier
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Andrea S. de Sousa
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
- Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Andrea R. Costa
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Marcelo T. de Holanda
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Henrique H. Veloso
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Fernanda S.N.S. Mendes
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Filipe A.C. Costa
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Marcio N. Boia
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
- Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Pedro E.A.A. Brasil
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Fernanda M. Carneiro
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | | | - Mauro F.F. Mediano
- Evandro Chagas National Institute of Infectious Disease, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
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Vallejo M, Reyes PP, Martinez Garcia M, Gonzalez Garay AG. Trypanocidal drugs for late-stage, symptomatic Chagas disease (Trypanosoma cruzi infection). Cochrane Database Syst Rev 2020; 12:CD004102. [PMID: 33305846 PMCID: PMC8103997 DOI: 10.1002/14651858.cd004102.pub3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND People with Chagas disease may develop progressive and lethal heart conditions. Drugs to eliminate the parasite Trypanosoma cruzi (T cruzi) currently carry limited therapeutic value and are used in the early stages of the disease. Extending the use of these drugs to treat chronic chagasic cardiomyopathy (CCC) has also been proposed. OBJECTIVES To assess the benefits and harms of nitrofurans and trypanocidal drugs for treating late-stage, symptomatic Chagas disease and CCC in terms of blood parasite reduction or clearance, mortality, adverse effects, and quality of life. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and LILACS databases on 12 November 2019. We also searched two clinical trials registers, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), on 3 December 2019. SELECTION CRITERIA We included randomised controlled trials (RCTs) assessing trypanocidal drugs versus placebo or no treatment for late-stage, symptomatic Chagas disease and CCC. DATA COLLECTION AND ANALYSIS We conducted the reporting of the review according the standard Cochrane methods. Two review authors independently retrieved articles, performed data extraction, and assessed risk of bias. Any disagreements were resolved by a third review author. We contacted study authors for additional information. MAIN RESULTS We included two studies in this review update. One RCT randomly assigned 26 participants to benznidazole 5 mg/kg/day; 27 participants to nifurtimox 5 mg/kg/day; and 24 participants to placebo for 30 days. The second RCT, newly included in this update, randomised 1431 participants to benznidazole 300 mg/day for 40 to 80 days and 1423 participants to placebo. We also identified one ongoing study. Benznidazole compared to placebo At five-year follow-up, low quality of the evidence suggests that there may be a benefit of benznidazole when compared to placebo for clearance or reduction of antibody titres (risk ratio (RR) 1.25, 95% confidence interval (CI) 1.14 to 1.37; 1 trial; 1896 participants). We are uncertain about the effects of benznidazole for the clearance of parasitaemia demonstrated by negative xenodiagnosis, blood culture, and/or molecular assays due to very limited evidence. Low quality of the evidence suggests that when compared to placebo, benznidazole may make little to no difference in the risk of heart failure (RR 0.89, 95% CI 0.69 to 1.14; 1 trial; 2854 participants) and ventricular tachycardia (RR 0.80, 95% CI 0.51 to 1.26; 1 trial; 2854 participants). We found moderate quality of the evidence that adverse events increase with benznidazole when compared to placebo (RR 2.52, 95% CI 2.09 to 3.03; 1 trial; 2854 participants). Adverse effects were observed in 23.9% of patients in the benznidazole group compared to 9.5% in the placebo group. The most frequent adverse effects were: cutaneous rash, gastrointestinal symptoms, and peripheral polyneuropathy. No data were available for the outcomes of pathological demonstration of tissue parasites and quality of life. Nifurtimox compared to placebo Data were only available for this comparison for the outcome clearance or reduction of antibody titres, and we are uncertain about the effect due to very limited evidence. Regarding adverse events, one RCT mentioned in a general manner that nifurtimox caused intense adverse events, without any quantification. AUTHORS' CONCLUSIONS There is insufficient evidence to support the efficacy of the trypanocidal drugs benznidazole and nifurtimox for late-stage, symptomatic Chagas disease and CCC.
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Affiliation(s)
- Maite Vallejo
- Instituto Nacional de Cardiología Ignacio Chávez, Juan Badiano No. 1. Col. Seccion XVI, Tlalpan, Mexico
| | - Pedro Pa Reyes
- Instituto Nacional de Cardiología Ignacio Chávez, Juan Badiano No. 1. Col. Seccion XVI, Tlalpan, Mexico
| | - Mireya Martinez Garcia
- Sociomedical Research Unit, Instituto Nacional de Cardiologia, Ignacio Chavez, Mexico City, Mexico
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Buss LF, Campos de Oliveira- da Silva L, Moreira CHV, Manuli ER, Sales FC, Morales I, Di Germanio C, de Almeida-Neto C, Bakkour S, Constable P, Pinto-Filho MM, Ribeiro AL, Busch M, Sabino EC. Declining antibody levels to Trypanosoma cruzi correlate with polymerase chain reaction positivity and electrocardiographic changes in a retrospective cohort of untreated Brazilian blood donors. PLoS Negl Trop Dis 2020; 14:e0008787. [PMID: 33108390 PMCID: PMC7647114 DOI: 10.1371/journal.pntd.0008787] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 11/06/2020] [Accepted: 09/09/2020] [Indexed: 02/06/2023] Open
Abstract
Background Although infection with Trypanosoma cruzi is thought to be lifelong, less than half of those infected develop cardiomyopathy, suggesting greater parasite control or even clearance. Antibody levels appear to correlate with T. cruzi (antigen) load. We test the association between a downwards antibody trajectory, PCR positivity and ECG alterations in untreated individuals with Chagas disease. Methodology/Principal findings This is a retrospective cohort of T. cruzi seropositive blood donors. Paired blood samples (index donation and follow-up) were tested using the VITROS Immunodiagnostic Products Anti-T.cruzi (Chagas) assay (Ortho Clinical Diagnostics, Raritan NJ) and PCR performed on the follow-up sample. A 12-lead resting ECG was performed. Significant antibody decline was defined as a reduction of > 1 signal-to-cutoff (S/CO) unit on the VITROS assay. Follow-up S/CO of < 4 was defined as borderline/low. 276 untreated seropositive blood donors were included. The median (IQR) follow-up was 12.7 years (8.5–16.9). 56 (22.1%) subjects had a significant antibody decline and 35 (12.7%) had a low/borderline follow-up result. PCR positivity was lower in the falling (26.8% vs 52.8%, p = 0.001) and low/borderline (17.1% vs 51.9%, p < 0.001) antibody groups, as was the rate of ECG abnormalities. Falling and low/borderline antibody groups were predominantly composed of individuals with negative PCR and normal ECG findings: 64% and 71%, respectively. Conclusions/Significance Low and falling antibody levels define a phenotype of possible spontaneous parasite clearance. Infection with the single-celled parasite Trypanosoma cruzi (Chagas disease) is thought to be lifelong. However, only a third of infected people develop Chagas cardiomyopathy–the main disease manifestation. This may reflect the different extent to which individuals control the parasite, with some potentially clearing it entirely. In chronically infected immunocompetent patients, a marker of parasite burden is the quantity of antibody against T. cruzi in the blood: more parasite, more immune stimulation, more antibody. In this study we show how antibody levels change over many years in a cohort of untreated patients with Chagas disease. We find that among individuals with falling or low/borderline antibody levels there was a lower rate of parasite detection in the blood and a lower rate of cardiomyopathy. 60% of subjects with falling antibody levels had no evidence of active disease, twice as many as among patients with other antibody trajectories (stable or rising). Our findings support an account of the natural history of Chagas disease in which a proportion of those infected achieve a greater control of the parasite, with some individuals potentially clearing it completely.
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Affiliation(s)
- Lewis F. Buss
- Instituto de Medicina Tropical da Faculdade de Medicina (FMUSP) da Universidade de São Paulo, São Paulo, Brazil
| | | | - Carlos H. V. Moreira
- Instituto de Medicina Tropical da Faculdade de Medicina (FMUSP) da Universidade de São Paulo, São Paulo, Brazil
| | - Erika R. Manuli
- Instituto de Medicina Tropical da Faculdade de Medicina (FMUSP) da Universidade de São Paulo, São Paulo, Brazil
| | - Flavia C. Sales
- Instituto de Medicina Tropical da Faculdade de Medicina (FMUSP) da Universidade de São Paulo, São Paulo, Brazil
| | - Ingra Morales
- Instituto de Medicina Tropical da Faculdade de Medicina (FMUSP) da Universidade de São Paulo, São Paulo, Brazil
| | - Clara Di Germanio
- Vitalant Research Institute, San Francisco, CA, United States of America
| | | | - Sonia Bakkour
- Vitalant Research Institute, San Francisco, CA, United States of America
| | - Paul Constable
- Ortho Clinical Diagnostics, Rochester, NY, United States of America
| | - Marcelo M. Pinto-Filho
- Telehealth Center, Hospital das Clínicas, and Internal Medicine Department, School of Medicine, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Antonio L. Ribeiro
- Telehealth Center, Hospital das Clínicas, and Internal Medicine Department, School of Medicine, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Michael Busch
- Vitalant Research Institute, San Francisco, CA, United States of America
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA, United States of America
| | - Ester C. Sabino
- Instituto de Medicina Tropical da Faculdade de Medicina (FMUSP) da Universidade de São Paulo, São Paulo, Brazil
- * E-mail:
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11
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Meyers AC, Purnell JC, Ellis MM, Auckland LD, Meinders M, Hamer SA. Nationwide Exposure of U.S. Working Dogs to the Chagas Disease Parasite, Trypanosoma cruzi. Am J Trop Med Hyg 2020; 102:1078-1085. [PMID: 32189615 PMCID: PMC7204581 DOI: 10.4269/ajtmh.19-0582] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Trypanosoma cruzi is a zoonotic protozoan parasite vectored by triatomine insects that are endemic to the Americas, including the southern United States. Surveillance of domestic dogs for T. cruzi exposure allows for the determination of geographic regions of transmission that are relevant for human and animal health. The U.S. Department of Homeland Security (DHS) working dogs provide critical security and detection services across the country, and many train or work in the southern United States, where they are at risk for T. cruzi exposure. We sampled blood from 1,610 working dogs (predominantly Belgian Malinois, German shepherds, and Labrador retrievers) from six task forces (including the Transportation Security Administration, Customs and Border Protection, Secret Service, and more) and two canine training centers across 41 states from 2015 to 2018. Canine sera that were reactive on at least two independent serological assays were considered positive for anti-T.-cruzi antibodies. In addition, up to three independent polymerase chain reaction (PCR) assays were used to detect and type T. cruzi DNA. Overall seroprevalence was 7.5%, and four dogs (0.25%, n = 1,610) had detectable parasite DNA in the blood, comprising parasite discrete taxonomic units (DTUs) TcIV and a coinfection of TcI/TcIV. Dogs that worked within versus outside of the geographic range of established triatomines showed comparable seroprevalence (7.3% and 9.2%, respectively; P = 0.61). Determining the prevalence of T. cruzi in these working dogs and looking at spatially associated risk factors have practical implications for disease risk management and could assist with improved control measures to protect both animal and human health.
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Affiliation(s)
- Alyssa C Meyers
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
| | - Julia C Purnell
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
| | - Megan M Ellis
- College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Lisa D Auckland
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
| | - Marvin Meinders
- Department of Homeland Security, Office of Health Affairs, Washington, District of Columbia
| | - Sarah A Hamer
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
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12
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Chagas disease: Historic perspective. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165689. [DOI: 10.1016/j.bbadis.2020.165689] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 01/02/2020] [Accepted: 01/15/2020] [Indexed: 12/13/2022]
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A Parasite Biomarker Set for Evaluating Benznidazole Treatment Efficacy in Patients with Chronic Asymptomatic Trypanosoma cruzi Infection. Antimicrob Agents Chemother 2019; 63:AAC.02436-18. [PMID: 31358581 DOI: 10.1128/aac.02436-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 07/18/2019] [Indexed: 12/20/2022] Open
Abstract
One of the current greatest challenges of Chagas disease is the establishment of biomarkers to assess the efficacy of drugs in a short period of time. In this context, the reactivity of sera from 66 adults with chronic indeterminate Chagas disease (IND) for a set of four Trypanosoma cruzi antigens (KMP11, PFR2, HSP70, and 3973d) was analyzed before and after benznidazole treatment. The results showed that the reactivity against these antigens decreased at 9, 24, and 48 months after treatment. Moreover, the 42.4% and 68.75% of IND patients met the established standard criteria of therapeutic efficacy (STEC) at 24 and 48 months posttreatment, respectively. Meeting the STEC implied that there was a continuous decrease in the reactivity of the patient sera against the four antigens after treatment and that there was a substantial decrease in the reactivity for at least two of the antigens. This important decrease in reactivity may be associated with a drastic reduction in the parasite load, but it is not necessarily associated with a parasitological cure. After treatment, a positive PCR result was only obtained in patients who did not meet the STEC. The percentage of granzyme B+/perforin+ CD8+ T cells was significantly higher in patients who met the STEC than in those who did not meet the STEC (35.2% versus 2.2%; P < 0.05). Furthermore, the patients who met the STEC exhibited an increased quality of the multifunctional response of the antigen-specific CD8+ T cells compared with that in the patients who did not meet the STEC.
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Caldas IS, Santos EG, Novaes RD. An evaluation of benznidazole as a Chagas disease therapeutic. Expert Opin Pharmacother 2019; 20:1797-1807. [PMID: 31456439 DOI: 10.1080/14656566.2019.1650915] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Introduction: As benznidazole is the first-line treatment for patients with Chagas disease, rational chemotherapy strategies are required based on the critical analysis of the evidence on the relevance and applicability of this drug at different disease stages. Areas covered: The authors discuss the current understanding of benznidazole-based chemotherapy for Chagas disease, focusing specifically on epidemiology, pharmacokinetics, mechanism of action, clinical recommendations, cure criteria, and therapeutic efficacy in different phases of the disease. Expert opinion: Benznidazole shows high bioavailability after oral administration. Benznidazole at 5-8 mg/kg/day and 5-10 mg/kg/day for 30-60 days are consistent clinical recommendations for children and adults, respectively. A high correlation between negative parasitological, serological, and polymerase chain reaction (PCR) assays in long-term post-therapeutic follow-up has been consistently used to evaluate therapeutic efficacy. These methods support the evidence that the success of benznidazole-based chemotherapy is closely correlated with the phase of infection in which the treatment is administered. The greater therapeutic efficacy is obtained in acute infections, gradually worsening as the infection becomes chronic. When therapeutic failure is confirmed by any diagnostic assay, benznidazole treatment does not always ensure better long-term prognosis, and Chagas cardiomyopathy may develop as well as in untreated patients.
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Affiliation(s)
- Ivo S Caldas
- Department of Pathology and Parasitology, Institute of Biomedical Sciences, Universidade Federal de Alfenas (UNIFAL-MG) , Alfenas , Minas Gerais , Brazil
| | - Elda G Santos
- Department of Structural Biology, Institute of Biomedical Sciences, Universidade Federal de Alfenas (UNIFAL-MG) , Alfenas , Minas Gerais , Brazil
| | - Rômulo D Novaes
- Department of Structural Biology, Institute of Biomedical Sciences, Universidade Federal de Alfenas (UNIFAL-MG) , Alfenas , Minas Gerais , Brazil
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15
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Meyers AC, Hamer SA, Matthews D, Gordon SG, Saunders AB. Risk factors and select cardiac characteristics in dogs naturally infected with Trypanosoma cruzi presenting to a teaching hospital in Texas. J Vet Intern Med 2019; 33:1695-1706. [PMID: 31119786 PMCID: PMC6639495 DOI: 10.1111/jvim.15516] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 05/03/2019] [Indexed: 12/18/2022] Open
Abstract
Background Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, causes sudden death and chronic heart disease with no currently approved treatment. Objective To report epidemiologic and select cardiac characteristics associated with T. cruzi infection in dogs presenting to a teaching hospital in Texas. Animals Three hundred seventy‐five client‐owned dogs. Methods A retrospective search of medical records identified dogs tested for T. cruzi antibodies or with histologic T. cruzi parasites. Data retrieved included signalment, location of residence, reported reason for testing, cardiac troponin I (cTnI) concentration, and ECG abnormalities. Results Trypanosoma cruzi‐infected dogs (N = 63, 16.8%) were significantly younger than negative dogs (N = 312) (mean, 5.9 ± 3.8 versus 7.4 ± 4.0 years; P = .007) with no difference by sex or breed. Ninety‐one breeds were tested; the highest percent infected were non‐sporting (10/35; 29%) and toy breed (10/42; 24%) groups. The odds of infection were 13 times greater among dogs with an infected housemate or littermate (95% confidence interval [CI], 3.94‐50.45; P < .001). Infected dogs were more likely to have ventricular arrhythmias (odds ratio [OR], 2.19; 95% CI, 1.15‐4.33, P = .02), combinations of ECG abnormalities (OR, 2.91; 95% CI, 1.37‐5.99; P = .004), and cTnI >0.129 ng/mL (ADVIA; OR, 10.71; 95% CI, 1.60‐212.21; P = .035). Conclusions and Clinical Importance Dogs infected with T. cruzi were identified in Texas in many breed groups including breeds affected by well‐described heart diseases that mimic Chagas disease suggesting a need for increased awareness, including knowledge of when to consider testing.
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Affiliation(s)
- Alyssa C Meyers
- Department of Veterinary Integrative Bioscience, Texas A&M University, College Station, Texas
| | - Sarah A Hamer
- Department of Veterinary Integrative Bioscience, Texas A&M University, College Station, Texas
| | - Derek Matthews
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Sonya G Gordon
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Ashley B Saunders
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas
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Bartsch SM, Bottazzi ME, Asti L, Strych U, Meymandi S, Falcón-Lezama JA, Randall S, Hotez PJ, Lee BY. Economic value of a therapeutic Chagas vaccine for indeterminate and Chagasic cardiomyopathy patients. Vaccine 2019; 37:3704-3714. [PMID: 31104883 DOI: 10.1016/j.vaccine.2019.05.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 05/06/2019] [Accepted: 05/09/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND Therapeutic vaccines to prevent Chagas disease progression to cardiomyopathy are under development because the only available medications (benznidazole and nifurtimox) are limited by their efficacy, long treatment course, and side effects. Better understanding the potential clinical and economic value of such vaccines can help guide development and implementation. METHODS We developed a computational Chagas Markov model to evaluate the clinical and economic value of a therapeutic vaccine given in conjunction with benznidazole in indeterminate and chronic Chagas patients. Scenarios explored the vaccine's impact on reducing drug treatment dosage, duration, and adverse events, and risk of disease progression. RESULTS When administering standard-of-care benznidazole to 1000 indeterminate patients, 148 discontinued treatment and 219 progressed to chronic disease, resulting in 119 Chagas-related deaths and 2293 DALYs, costing $18.9 million in lifetime societal costs. Compared to benznidazole-only, therapeutic vaccination administered with benznidazole (25-75% reduction in standard dose and duration), resulted in 37-111 more patients (of 1000) completing treatment, preventing 11-219 patients from progressing, 6-120 deaths, and 108-2229 DALYs (5-100% progression risk reduction), saving ≤$16,171 per patient. When vaccinating determinate Kuschnir class 1 Chagas patients, 10-197 fewer patients further progressed compared to benznidazole-only, averting 11-228 deaths and 144-3037 DALYs (5-100% progression risk reduction), saving ≤$34,059 per person. When vaccinating Kuschnir class 2 patients, 13-279 fewer progressed (279 with benznidazole-only), averting 13-692 deaths and 283-10,785 DALYs (5-100% progression risk reduction), saving ≤$89,759. Therapeutic vaccination was dominant (saved costs and provided health benefits) with ≥ 5% progression risk reduction, except when only reducing drug treatment regimen and adverse events, but remained cost-effective when costing <$200. CONCLUSIONS Our study helps outline the thresholds at which a therapeutic Chagas vaccine may be cost-effective (e.g., <5% reduction in preventing cardiac progression, 25% reduction in benznidazole treatment doses and duration) and cost-saving (e.g., ≥5% and 25%, respectively).
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Affiliation(s)
- Sarah M Bartsch
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, Baltimore, MD 21205, USA; Global Obesity Prevention Center (GOPC), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, Baltimore, MD 21205, USA
| | - Maria Elena Bottazzi
- National School of Tropical Medicine and Departments of Pediatrics and Molecular Virology & Microbiology, Baylor College of Medicine, One Baylor Plaza, BCM113 Houston, TX 77030, USA
| | - Lindsey Asti
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, Baltimore, MD 21205, USA; Global Obesity Prevention Center (GOPC), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, Baltimore, MD 21205, USA
| | - Ulrich Strych
- National School of Tropical Medicine and Departments of Pediatrics and Molecular Virology & Microbiology, Baylor College of Medicine, One Baylor Plaza, BCM113 Houston, TX 77030, USA
| | - Sheba Meymandi
- Center of Excellence for Chagas Disease at Olive View-UCLA Medical Center, 14445 Olive View Drive, Sylmar, CA 91342, USA
| | - Jorge Abelardo Falcón-Lezama
- Carlos Slim Foundation, Lago Zurich 245, Piso 20. Ampliación Granada, Del. Miguel Hidalgo, C.P. 11529 Ciudad de México, Mexico
| | - Samuel Randall
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, Baltimore, MD 21205, USA; Global Obesity Prevention Center (GOPC), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, Baltimore, MD 21205, USA
| | - Peter J Hotez
- National School of Tropical Medicine and Departments of Pediatrics and Molecular Virology & Microbiology, Baylor College of Medicine, One Baylor Plaza, BCM113 Houston, TX 77030, USA
| | - Bruce Y Lee
- Public Health Computational and Operational Research (PHICOR), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, Baltimore, MD 21205, USA; Global Obesity Prevention Center (GOPC), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, Baltimore, MD 21205, USA.
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Pack AD, Collins MH, Rosenberg CS, Tarleton RL. Highly competent, non-exhausted CD8+ T cells continue to tightly control pathogen load throughout chronic Trypanosoma cruzi infection. PLoS Pathog 2018; 14:e1007410. [PMID: 30419010 PMCID: PMC6258465 DOI: 10.1371/journal.ppat.1007410] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/26/2018] [Accepted: 10/17/2018] [Indexed: 12/21/2022] Open
Abstract
Trypanosoma cruzi infection is characterized by chronic parasitism of non-lymphoid tissues and is rarely eliminated despite potent adaptive immune responses. This failure to cure has frequently been attributed to a loss or impairment of anti-T. cruzi T cell responses over time, analogous to the T cell dysfunction described for other persistent infections. In this study, we have evaluated the role of CD8+ T cells during chronic T. cruzi infection (>100 dpi), with a focus on sites of pathogen persistence. Consistent with repetitive antigen exposure during chronic infection, parasite-specific CD8+ T cells from multiple organs expressed high levels of KLRG1, but exhibit a preferential accumulation of CD69+ cells in skeletal muscle, indicating recent antigen encounter in a niche for T. cruzi persistence. A significant proportion of CD8+ T cells in the muscle also produced IFNγ, TNFα and granzyme B in situ, an indication of their detection of and functional response to T. cruzi in vivo. CD8+ T cell function was crucial for the control of parasite burden during chronic infection as exacerbation of parasite load was observed upon depletion of this population. Attempts to improve T cell function by blocking PD-1 or IL-10, potential negative regulators of T cells, failed to increase IFNγ and TNFα production or to enhance T. cruzi clearance. These results highlight the capacity of the CD8+ T cell population to retain essential in vivo function despite chronic antigen stimulation and support a model in which CD8+ T cell dysfunction plays a negligible role in the ability of Trypanosoma cruzi to persist in mice. The parasite Trypanosoma cruzi establishes lifelong infections in humans and other mammals, leading to severe cardiac and gastrointestinal complications known as Chagas disease. Although the factors that enable T. cruzi persistence remain undefined, in this and many other infection models, pathogen persistence has been attributed to the exhaustion of the immune system, particularly of CD8+ T cells. Here, we show that the inability of hosts to fully resolve T. cruzi infection is not a result of immune exhaustion and that in fact the T. cruzi-specific CD8+ T cell population remains highly competent and actively suppresses parasite outgrowth throughout the chronic infection. These results demonstrate that compromised immunity is not the eventual outcome of all chronic infections and suggest that T. cruzi, and perhaps other pathogens, may employ alternative strategies to subvert immune clearance in the presence of highly functional pathogen-specific effectors. These findings also suggest that interventions to inhibit immune regulatory pathways or to otherwise boost existing immune responses in such infections, will have limited benefit.
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Affiliation(s)
- Angela D. Pack
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Matthew H. Collins
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
- Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Charles S. Rosenberg
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Rick L. Tarleton
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
- Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
- * E-mail:
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Zrein M, Granjon E, Gueyffier L, Caillaudeau J, Liehl P, Pottel H, Cardoso CS, Oliveira CDL, de Oliveira LC, Lee TH, Ferreira AM, Ribeiro ALP, Busch MP, Sabino EC. A novel antibody surrogate biomarker to monitor parasite persistence in Trypanosoma cruzi-infected patients. PLoS Negl Trop Dis 2018; 12:e0006226. [PMID: 29425201 PMCID: PMC5823467 DOI: 10.1371/journal.pntd.0006226] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 02/22/2018] [Accepted: 01/09/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Trypanosoma cruzi parasite, the causative agent of Chagas disease, infects about six million individuals in more than 20 countries. Monitoring parasite persistence in infected individuals is of utmost importance to develop and evaluate treatments to control the disease. Routine screening for infected human individuals is achieved by serological assays; PCR testing to monitor spontaneous or therapy-induced parasitological cure has limitations due to the low and fluctuating parasitic load in circulating blood. The aim of the present study is to evaluate a newly developed antibody profiling assay as an indirect method to assess parasite persistence based on waning of antibodies following spontaneous or therapy-induced clearance of the infection. METHODOLOGY/PRINCIPAL FINDINGS We designed a multiplex serology assay, an array of fifteen optimized T. cruzi antigens, to evaluate antibody diversity in 1654 serum samples from chronic Chagas patients. One specific antibody response (antibody 3, Ab3) showed a strong correlation with T. cruzi parasite persistence as determined by T. cruzi PCR positive results. High and sustained Ab3 signal was strongly associated with PCR positivity in untreated patients, whereas significant decline in Ab3 signals was observed in BZN-treated patients who cleared parasitemia based on blood PCR results. CONCLUSION/SIGNIFICANCE Ab3 is a new surrogate biomarker that strongly correlates with parasite persistence in chronic and benznidazole-treated Chagas patients. We hypothesize that Ab3 is induced and maintained by incessant stimulation of the immune system by tissue-based and shed parasites that are not consistently detectable by blood based PCR techniques. Hence, a simple immunoassay measurement of Ab3 could be beneficial for monitoring the infectious status of seropositive patients.
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Affiliation(s)
- Maan Zrein
- R&D, INFYNITY BIOMARKERS SAS, Lyon, France
| | | | | | | | | | - Hans Pottel
- Faculty of Medicine, University of Leuven (KULAK), Kortrijk, Belgium
| | - Clareci Silva Cardoso
- Federal University of São João del-Rey, Research Group in Epidemiology and New Technologies in Health-campus CCO, São João del-Rei, Brazil
| | - Claudia Di Lorenzo Oliveira
- Federal University of São João del-Rey, Research Group in Epidemiology and New Technologies in Health-campus CCO, São João del-Rei, Brazil
| | - Lea Campos de Oliveira
- Instituto de Medicina Tropical e Faculdade de Medicina (FMUSP) da Universidade de São Paulo, São Paulo, Brazil
- Laboratorio de Investigação Médica (LIM03), Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paolo, Brazil
| | - Tzong-Hae Lee
- Blood Systems Research Institute and University of California, San Francisco, California, United States of America
| | - Ariela Mota Ferreira
- Graduate Program in Health Sciences, State University of Montes Claros (Universidade Estadual de Montes Claros), Montes Claros, Minas Gerais, Brazil
| | - Antonio Luiz P. Ribeiro
- Hospital das Clínicas and School of Medicine, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Michael P. Busch
- Blood Systems Research Institute and University of California, San Francisco, California, United States of America
| | - Ester Cerdeira Sabino
- Instituto de Medicina Tropical e Faculdade de Medicina (FMUSP) da Universidade de São Paulo, São Paulo, Brazil
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Alvarez MG, Bertocchi GL, Cooley G, Albareda MC, Viotti R, Perez-Mazliah DE, Lococo B, Castro Eiro M, Laucella SA, Tarleton RL. Treatment Success in Trypanosoma cruzi Infection Is Predicted by Early Changes in Serially Monitored Parasite-Specific T and B Cell Responses. PLoS Negl Trop Dis 2016; 10:e0004657. [PMID: 27128444 PMCID: PMC4851297 DOI: 10.1371/journal.pntd.0004657] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 03/31/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Chagas disease is the highest impact parasitic disease in Latin America. We have proposed that changes in Trypanosoma cruzi-specific immune responses might serve as surrogate indicators of treatment success. Herein, we addressed in a long-term follow-up study whether cure achieved after treatment can be predicted by changes in non-conventional indexes of anti-parasite serological and T cell activities. METHODOLOGY/PRINCIPAL FINDINGS T. cruzi-specific T cell responses, as measured by interferon-γ ELISPOT and T. cruzi-specific antibodies assessed by ELISA, hemagglutination and immunofluorescence tests as well as by a multiplex assay incorporating 14 recombinant T. cruzi proteins were measured in 33 patients at 48-150 months post-benznidazole treatment. Cure - as assessed by conventional serological tests - was associated with an early decline in T. cruzi-specific IFN-γ-producing T cells and in antibody titers measured by the multiplex serological assay. Changes in the functional status and potential of T. cruzi-specific T cells, indicative of reduced antigen stimulation, provided further evidence of parasitological cure following benznidazole treatment. Patients showing a significant reduction in T. cruzi-specific antibodies had higher pre-therapy levels of T. cruzi-specific IFN-γ- producing T cells compared to those with unaltered humoral responses post-treatment. CONCLUSIONS/SIGNIFICANCE Monitoring of appropriate immunological responses can provide earlier and robust measures of treatment success in T. cruzi infection.
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Affiliation(s)
- María G. Alvarez
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
| | | | - Gretchen Cooley
- Center for Tropical and Emerging Global Diseases, Athens, Georgia, United States of America
| | - María C. Albareda
- Instituto Nacional de Parasitología Dr. Mario Fatala Chaben, Buenos Aires, Argentina
| | - Rodolfo Viotti
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
| | | | - Bruno Lococo
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
| | - Melisa Castro Eiro
- Instituto Nacional de Parasitología Dr. Mario Fatala Chaben, Buenos Aires, Argentina
| | - Susana A. Laucella
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
- Instituto Nacional de Parasitología Dr. Mario Fatala Chaben, Buenos Aires, Argentina
| | - Rick L. Tarleton
- Center for Tropical and Emerging Global Diseases, Athens, Georgia, United States of America
- * E-mail:
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Sguassero Y, Cuesta CB, Roberts KN, Hicks E, Comandé D, Ciapponi A, Sosa-Estani S. Course of Chronic Trypanosoma cruzi Infection after Treatment Based on Parasitological and Serological Tests: A Systematic Review of Follow-Up Studies. PLoS One 2015; 10:e0139363. [PMID: 26436678 PMCID: PMC4593559 DOI: 10.1371/journal.pone.0139363] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 09/11/2015] [Indexed: 12/24/2022] Open
Abstract
Background Chagas disease is caused by the flagellate protozoan Trypanosoma cruzi (T. cruzi). It is endemic in Latin American countries outside the Caribbean. The current criterion for cure in the chronic phase of the disease is the negativization of at least two serological tests such as enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IIF) and indirect hemagglutination assay (IHA). The serological evolution of treated subjects with chronic T. cruzi infection is variable. Treatment failure is indicated by a positive parasitological and/or molecular test (persistence of parasitemia). Objectives To summarize the pattern of response to treatment of parasitological, molecular and serological tests performed during the follow-up of subjects with chronic T. cruzi infection. Methods Electronic searches in relevant databases and screening of citations of potentially eligible articles were accomplished. Organizations focusing on neglected infectious diseases were asked for help in identifying relevant studies. Included studies were randomized controlled trials (RCTs), quasi-RCTs, and cohort studies involving adults and children with chronic infection who received trypanocidal treatment (benznidazole or nifurtimox) and were followed over time. The assessment of risk of bias was performed separately for each study design. The Cochrane Collaboration’s tool and the guidelines developed by Hayden et al. were used. Two reviewers extracted all data independently. A third review author was consulted in case of discordant opinion. Additional analyses were defined in ad-hoc basis. Scatter plots for percentage of positive parasitological and molecular tests and for negative serological tests were developed by using the lowess curve technique. Heterogeneity was measured by I2. The protocol was registered in PROSPERO, an international prospective register of systematic review protocols (Registration Number CRD42012002162). Results Out of 2,136 citations screened, 54 studies (six RCTs and 48 cohort studies) were included. The smoothed curves for positive xenodiagnosis and positive polymerase chain reaction (PCR) were characterized by a sharp decrease at twelve month posttreatment. Afterwards, they reached 10–20% and 40% for xenodiagnosis and PCR, respectively. The smoothed curves for negative conventional serological tests increased up to 10% after 48 months of treatment. In the long-term, the rate of negativization was between 20% and 45%. The main sources of bias identified across cohort studies were the lack of control for confounding and attrition bias. In general, RCTs were judged as low risk of bias in all domains. The level of heterogeneity across included studies was moderate to high. Additional analysis were incomplete because of the limited availability of data. In this regard, the country of origin of study participants might affect the results of parasitological and molecular tests, while the level of risk of bias might affect serological outcomes. Subgroup analysis suggested that seronegativization occurs earlier in children compared to adults. Conclusions We acknowledge that there is a dynamic pattern of response based on parasitological, molecular and serological tests in subjects chronically infected with T. cruzi after treatment. Our findings suggest a trypanocidal effect in the long-term follow-up. Further research is needed to explore potential sources of heterogeneity and to conduct reliable subgroup analysis.
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Affiliation(s)
- Yanina Sguassero
- Centro Rosarino de Estudios Perinatales (CREP), Cochrane Centre CREP, Rosario, Santa Fe, Argentina
- Instituto Nacional de Parasitología (INP), “Dr Mario Fatala Chaben”, Administración Nacional de Laboratorios e Institutos de Salud (ANLIS) Malbrán, Buenos Aires, Argentina
| | - Cristina B. Cuesta
- Facultad de Ciencias Económicas y Estadística, Universidad Nacional de Rosario, Santa Fe, Argentina
| | - Karen N. Roberts
- Facultad de Ciencias Económicas y Estadística, Universidad Nacional de Rosario, Santa Fe, Argentina
| | - Elizabeth Hicks
- Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Daniel Comandé
- Instituto de Efectividad Clínica y Sanitaria (IECS), Cochrane Centre IECS, Buenos Aires, Argentina
| | - Agustín Ciapponi
- Instituto de Efectividad Clínica y Sanitaria (IECS), Cochrane Centre IECS, Buenos Aires, Argentina
| | - Sergio Sosa-Estani
- Instituto Nacional de Parasitología (INP), “Dr Mario Fatala Chaben”, Administración Nacional de Laboratorios e Institutos de Salud (ANLIS) Malbrán, Buenos Aires, Argentina
- * E-mail:
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Albareda MC, Laucella SA. Modulation of Trypanosoma cruzi-specific T-cell responses after chemotherapy for chronic Chagas disease. Mem Inst Oswaldo Cruz 2015; 110:414-21. [PMID: 25993507 PMCID: PMC4489479 DOI: 10.1590/0074-02760140386] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 03/20/2015] [Indexed: 01/07/2023] Open
Abstract
The aim of this review is to describe the contributions of the knowledge of T-cell responses to the understanding of the physiopathology and the responsiveness to etiological treatment during the chronic phase of Chagas disease. T-helper (Th)1 and interleukin (IL)-10 Trypanosoma cruzi-specific T-cells have been linked to the asymptomatic phase or to severe clinical forms of the disease, respectively or vice versa, depending on the T. cruzi antigen source, the patient's location and the performed immunological assays. Parasite-specific T-cell responses are modulated after benznidazole (BZ) treatment in chronically T. cruzi-infected subjects in association with a significant decrease in T. cruzi-specific antibodies. Accumulating evidence has indicated that treatment efficacy during experimental infection with T. cruzi results from the combined action of BZ and the activation of appropriate immune responses in the host. However, strong support of this interaction in T. cruzi-infected humans remains lacking. Overall, the quality of T-cell responses might be a key factor in not only disease evolution, but also chemotherapy responsiveness. Immunological parameters are potential indicators of treatment response regardless of achievement of cure. Providing tools to monitor and provide early predictions of treatment success will allow the development of new therapeutic options.
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Bustamante J, Tarleton R. Reaching for the Holy Grail: insights from infection/cure models on the prospects for vaccines for Trypanosoma cruzi infection. Mem Inst Oswaldo Cruz 2015; 110:445-51. [PMID: 25946159 PMCID: PMC4489482 DOI: 10.1590/0074-02760140440] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 02/25/2015] [Indexed: 11/21/2022] Open
Abstract
Prevention of Trypanosoma cruzi infection in mammals likely depends
on either prevention of the invading trypomastigotes from infecting host cells or the
rapid recognition and killing of the newly infected cells by T.
cruzi-specific T cells. We show here that multiple rounds of infection
and cure (by drug therapy) fails to protect mice from reinfection, despite the
generation of potent T cell responses. This disappointing result is similar to that
obtained with many other vaccine protocols used in attempts to protect animals
from T. cruzi infection. We have previously shown that immune
recognition of T. cruzi infection is significantly delayed both at
the systemic level and at the level of the infected host cell. The systemic delay
appears to be the result of a stealth infection process that fails to trigger
substantial innate recognition mechanisms while the delay at the cellular level is
related to the immunodominance of highly variable gene family proteins, in particular
those of the trans-sialidase family. Here we discuss how these previous studies and
the new findings herein impact our thoughts on the potential of prophylactic
vaccination to serve a productive role in the prevention of T. cruzi
infection and Chagas disease.
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Affiliation(s)
- Juan Bustamante
- Centro de Investigación en Salud Internacional de Barcelona, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Rick Tarleton
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
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Follow-up of an asymptomatic Chagas disease population of children after treatment with nifurtimox (Lampit) in a sylvatic endemic transmission area of Colombia. PLoS Negl Trop Dis 2015; 9:e0003465. [PMID: 25723465 PMCID: PMC4344301 DOI: 10.1371/journal.pntd.0003465] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 12/09/2014] [Indexed: 01/18/2023] Open
Abstract
Background Chagas disease is an anthropozoonosis caused by Trypanosoma cruzi. Two drugs are currently used for the etiological treatment of the disease: Nifurtimox (Lampit) and Benznidazole. This study presents a quasi-experimental trial (non-control group) of sixty-two patients who were treated for Chagas disease with Nifurtimox (Lampit), and were then followed for 30 months post-treatment. The safety of Nifurtimox (Lampit) for Chagas disease in this group of children primarily between 4 and 19 years old was also evaluated. Materials and methods The 62 patients included in the study were selected when resulted seropositive for two out of three fundamentally different serological tests. All children were treated during two months according to protocols established by WHO. Monitoring was performed every twenty days to evaluate treatment safety. In 43 patients, two different serological tests: ELISA and IFAT; and two parasitological tests: blood culture, and real time PCR, (qPCR) were performed to assess therapeutic response, defined as post-treatment serological negativization. Principal findings All patients completed the treatment successfully, and six patients abandoned the post-treatment follow-up. Adverse effects occurred in 74% of patients, but only 4.8% of cases required temporary suspension to achieve 100% adherence to the 60-day treatment, and all symptoms reverted after treatment completion. Both parasite load (measured through qPCR) and antibodies (ELISA absorbance) evidenced a significant median reduction 6 months after treatment from 6.2 to 0.2 parasite equivalents/mL, and from 0.6 to 0.2 absorbance units respectively (p<0.001). Serological negativization by ELISA was evident since 6 months post-treatment, whereas by IFAT only after 18 months. Serological negativization by the two tests (ELISA and IFAT) was 41.9% (95%CI: 26.5–57.3) after 30 months post-treatment. qPCR was positive in 88.3% of patients pre-treatment and only in 12.1% of patients after 30 months. Survival analysis indicated that only 26.3% (95%CI: 15.5–44.8) persisted with negative qPCR during the whole follow-up period. Conclusions Nifurtimox was very well tolerated and successfully reduced parasite load and antibody titers. Re-infection, lysed parasites or a lack of anti-parasitic activity could explain these persistently positive qPCR cases. Chagas disease is currently treated with two drugs, Benznidazole (BNZ) and Nifurtimox (NFX). The need to find the ideal diagnostic technique for post treatment evaluation still exists, due to the known flaws of the currently used techniques. We performed an evaluation of the safety and effectiveness of Nifurtimox treatment in a population of 62 children infected with Trypanosoma cruzi in an endemic Colombian area. The effectiveness was evaluated with two serological tests (IFAT and ELISA), and with two parasitological tests (blood culture and qPCR). We suggest the use of qPCR as a marker of response in all future treatment evaluations for Chagas disease, due to its potential to detect early treatment failure and/or reinfection. In order to have more conclusive results, it is important to perform this kind of study in a controlled environment, wherein the risk of reinfection is not considered.
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Abstract
The discovery of new therapeutic options against Trypanosoma cruzi, the causative agent of Chagas disease, stands as a fundamental need. Currently, there are only two drugs available to treat this neglected disease, which represents a major public health problem in Latin America. Both available therapies, benznidazole and nifurtimox, have significant toxic side effects and their efficacy against the life-threatening symptomatic chronic stage of the disease is variable. Thus, there is an urgent need for new, improved anti–T. cruzi drugs. With the objective to reliably accelerate the drug discovery process against Chagas disease, several advances have been made in the last few years. Availability of engineered reporter gene expressing parasites triggered the development of phenotypic in vitro assays suitable for high throughput screening (HTS) as well as the establishment of new in vivo protocols that allow faster experimental outcomes. Recently, automated high content microscopy approaches have also been used to identify new parasitic inhibitors. These in vitro and in vivo early drug discovery approaches, which hopefully will contribute to bring better anti–T. cruzi drug entities in the near future, are reviewed here.
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Rodriguez HO, Guerrero NA, Fortes A, Santi-Rocca J, Gironès N, Fresno M. Trypanosoma cruzi strains cause different myocarditis patterns in infected mice. Acta Trop 2014; 139:57-66. [PMID: 25017312 DOI: 10.1016/j.actatropica.2014.07.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/03/2014] [Accepted: 07/03/2014] [Indexed: 10/25/2022]
Abstract
AIMS Chagas disease pathology is dependent on the infecting Trypanosoma cruzi strain. However, the relationship between the extent and type of myocarditis caused by different T. cruzi strains in the acute and chronic phases of infection has not been studied in detail. To address this, we infected mice with three genetically distant T. cruzi strains as well as infected in vitro different cell types. METHODS AND RESULTS Parasitemia was detected in mice infected with the Y and VFRA strains, but not with the Sc43 strain; however, only the Y strain was lethal. When infected with VFRA, mice showed higher inflammation and parasitism in the heart than with Sc43 strain. Y and VFRA caused homogeneous pancarditis with inflammatory infiltrates along the epicardium, whereas Sc43 caused inflammation preferentially in the auricles in association with intracellular parasite localization. We observed intramyocardic perivasculitis in mice infected with the VFRA and Y strains, but not with Sc43, during the acute phase, which suggests that endothelial cells may be involved in heart colonization by these more virulent strains. In in vitro infection assays, the Y strain had the highest parasite-cell ratio in epithelial, macrophage and endothelial cell lines, but Y and VFRA strains were higher than Sc43 in cardiomyocytes. CONCLUSIONS This study supports parasite variability as a cause for the diverse cardiac outcomes observed in Chagas disease, and suggests that endothelial cells could be involved in heart infection during the acute phase.
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Albareda MC, De Rissio AM, Tomas G, Serjan A, Alvarez MG, Viotti R, Fichera LE, Esteva MI, Potente D, Armenti A, Tarleton RL, Laucella SA. Polyfunctional T cell responses in children in early stages of chronic Trypanosoma cruzi infection contrast with monofunctional responses of long-term infected adults. PLoS Negl Trop Dis 2013; 7:e2575. [PMID: 24349591 PMCID: PMC3861186 DOI: 10.1371/journal.pntd.0002575] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Accepted: 10/22/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Adults with chronic Trypanosoma cruzi exhibit a poorly functional T cell compartment, characterized by monofunctional (IFN-γ-only secreting) parasite-specific T cells and increased levels of terminally differentiated T cells. It is possible that persistent infection and/or sustained exposure to parasites antigens may lead to a progressive loss of function of the immune T cells. METHODOLOGY/PRINCIPAL FINDINGS To test this hypothesis, the quality and magnitude of T. cruzi-specific T cell responses were evaluated in T. cruzi-infected children and compared with long-term T. cruzi-infected adults with no evidence of heart failure. The phenotype of CD4(+) T cells was also assessed in T. cruzi-infected children and uninfected controls. Simultaneous secretion of IFN-γ and IL-2 measured by ELISPOT assays in response to T. cruzi antigens was prevalent among T. cruzi-infected children. Flow cytometric analysis of co-expression profiles of CD4(+) T cells with the ability to produce IFN-γ, TNF-α, or to express the co-stimulatory molecule CD154 in response to T. cruzi showed polyfunctional T cell responses in most T. cruzi-infected children. Monofunctional T cell responses and an absence of CD4(+)TNF-α(+)-secreting T cells were observed in T. cruzi-infected adults. A relatively high degree of activation and differentiation of CD4(+) T cells was evident in T. cruzi-infected children. CONCLUSIONS/SIGNIFICANCE Our observations are compatible with our initial hypothesis that persistent T. cruzi infection promotes eventual exhaustion of immune system, which might contribute to disease progression in long-term infected subjects.
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Affiliation(s)
- María C. Albareda
- Instituto Nacional de Parasitología Dr. M. Fatala Chaben, Buenos Aires, Argentina
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
| | - Ana M. De Rissio
- Instituto Nacional de Parasitología Dr. M. Fatala Chaben, Buenos Aires, Argentina
| | - Gonzalo Tomas
- Instituto Nacional de Parasitología Dr. M. Fatala Chaben, Buenos Aires, Argentina
| | | | - María G. Alvarez
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
| | - Rodolfo Viotti
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
| | - Laura E. Fichera
- Instituto Nacional de Parasitología Dr. M. Fatala Chaben, Buenos Aires, Argentina
| | - Mónica I. Esteva
- Instituto Nacional de Parasitología Dr. M. Fatala Chaben, Buenos Aires, Argentina
| | - Daniel Potente
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
| | - Alejandro Armenti
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
| | - Rick L. Tarleton
- Center for Tropical and Emerging Global Diseases, Athens, Georgia, United States of America
| | - Susana A. Laucella
- Instituto Nacional de Parasitología Dr. M. Fatala Chaben, Buenos Aires, Argentina
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
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Viotti R, Alarcón de Noya B, Araujo-Jorge T, Grijalva MJ, Guhl F, López MC, Ramsey JM, Ribeiro I, Schijman AG, Sosa-Estani S, Torrico F, Gascon J. Towards a paradigm shift in the treatment of chronic Chagas disease. Antimicrob Agents Chemother 2013; 58:635-9. [PMID: 24247135 PMCID: PMC3910900 DOI: 10.1128/aac.01662-13] [Citation(s) in RCA: 156] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Treatment for Chagas disease with currently available medications is recommended universally only for acute cases (all ages) and for children up to 14 years old. The World Health Organization, however, also recommends specific antiparasite treatment for all chronic-phase Trypanosoma cruzi-infected individuals, even though in current medical practice this remains controversial, and most physicians only prescribe palliative treatment for adult Chagas patients with dilated cardiomyopathy. The present opinion, prepared by members of the NHEPACHA network (Nuevas Herramientas para el Diagnóstico y la Evaluación del Paciente con Enfermedad de Chagas/New Tools for the Diagnosis and Evaluation of Chagas Disease Patients), reviews the paradigm shift based on clinical and immunological evidence and argues in favor of antiparasitic treatment for all chronic patients. We review the tools needed to monitor therapeutic efficacy and the potential criteria for evaluation of treatment efficacy beyond parasitological cure. Etiological treatment should now be mandatory for all adult chronic Chagas disease patients.
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Affiliation(s)
- R. Viotti
- Hospital Interzonal General de Agudos (HIGA) Eva Perón, Sección Chagas, Servicio de Cardiología, Buenos Aires, Argentina
| | - B. Alarcón de Noya
- Instituto de Medicina Tropical, Universidad Central de Venezuela (IMT-UCV), Caracas, Venezuela
| | - T. Araujo-Jorge
- Fundação Oswaldo Cruz—Instituto Oswaldo Cruz (FIOCRUZ-IOC), Programa Integrado de Doença de Chagas, Laboratório de Inovações em Terapias, Ensino e Bioprodutos, Río de Janeiro, Brazil
| | - M. J. Grijalva
- Centro de Investigación de Enfermedades Infecciosas de la Pontificia Universidad Católica del Ecuador (CIEI-PUCE), Quito, Ecuador, and Tropical Disease Institute, Ohio University (TDI-OU), Athens, Ohio, USA
| | - F. Guhl
- Centro de Investigaciones en Microbiología y Parasitología Tropical, Universidad de los Andes (UA-CIMPAT), Bogotá, Colombia
| | - M. C. López
- Instituto de Parasitología y Biomedicina Lopez-Neyra-Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), Granada, Spain
| | - J. M. Ramsey
- Centro Regional de Investigación en Salud Pública, Instituto Nacional de Salud Pública (CRISP-INSP), Tapachula, Chiapas, Mexico
| | - I. Ribeiro
- Drugs for Neglected Diseases Initiative (DNDi), Geneva, Switzerland
| | - A. G. Schijman
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), CONICET, Buenos Aires, Argentina
| | - S. Sosa-Estani
- Instituto Nacional de Parasitología Dr. Mario Fatala Chaben (INP)-ANLIS Dr. Carlos G. Malbran, Buenos Aires, Argentina
| | - F. Torrico
- Universidad Mayor de San Simón (UMSS), Cochabamba, Bolivia
| | - J. Gascon
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), CONICET, Buenos Aires, Argentina
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