Follow-up of dairy cattle naturally infected by Trypanosoma vivax after treatment with isometamidium chloride / Acompanhamento de bovinos leiteiros naturalmente infectados com Trypanosoma vivax após tratamento com cloreto de isometamidium

Abstract Trypanosoma vivax infections cause nonspecific clinical signs in cattle associated with aparasitemic intervals, making disease diagnosis a challenge. In Brazil, diminazene aceturate and isometamidium chloride (ISM) are available to treat bovine trypanosomosis. The objective of this study was to follow-up, by molecular and serological techniques, dairy cattle naturally infected by T. vivax after ISM treatment. Thirty cattle naturally infected with T. vivax received two applications of ISM, at a dosage of 1.0 mg/kg intramuscularly, on days 0 and 150. For T. vivax diagnosis, EDTA-blood and serum samples were evaluated on 0, 7, 15, 30, 60, 90, 120, 150, 180, 210, and 240 days after treatment PCR, Loop-mediated isothermal amplification (LAMP) and ELISA. Animals with persistent detection of T. vivax DNA by both PCR and LAMP were found and continuous detection of anti-T. vivax IgG antibodies by ELISA, suggesting the presence of T. vivax resistance to ISM. The combination of LAMP and ELISA tests can prevent misdiagnosis of the parasite clearance in treated cattle, contributing to better disease control. This is the first experiment that demonstrates the persistence infection of T. vivax under ISM treatment in a natural infected herd and evidence of ISM chemotherapy-resistant T. vivax in Brazil.

Resumo Em bovinos, infecções por Trypanosoma vivax geram sinais clínicos inespecíficos que, associados a intervalos aparasitêmicos, faz com que o diagnóstico da enfermidade seja desafiador. No Brasil, somente aceturato de diaminazeno e cloridrato de isometamidum (ISM) estão disponíveis para o tratamento da tripanossomose bovina. Este trabalho teve como objetivo acompanhar bovinos leiteiros naturalmente infectados por T. vivax, após o tratamento com ISM por meio de técnicas moleculares e sorológica. Foram utilizados 30 bovinos naturalmente infectados com T. vivax, sendo estes tratados com duas aplicações de ISM, na dosagem de 1,0 mg/kg por via intramuscular profunda, nos dias 0 e 150. Foram avaliadas, para diagnóstico de T. vivax, amostras de sangue acrescido de EDTA e soro, colhidas nos 0, 7, 15, 30, 60, 90, 120, 150, 180, 210 e 240 dias após os tratamentos pela reação em cadeia da polimerase (PCR), amplificação circular isotérmica do DNA (LAMP) e ensaio de imunoabsorção enzimático (ELISA). Verificou-se a presença de animais com persistência na detecção de DNA de T. vivax pela PCR e LAMP, bem como detecção contínua de anticorpos IgG anti-T. vivax pelo método de ELISA, sugerindo a presença de resistência de T. vivax ao ISM. A combinação dos testes LAMP e ELISA pode evitar falsos diagnósticos da eliminação do parasita nos bovinos tratados, contribuindo para um melhor controle da doença. Este é o primeiro experimento que demonstra infecção persistente do T. vivax em rebanho naturalmente infectado, tratado com ISM, e evidencia possível resistência ao quimioterápico no Brasil.

Antiparasitic and anti-inflammatory activities of ß-lapachone-derived naphthoimidazoles in experimental acute Trypanosoma cruzi infection

BACKGROUND Chagas disease, which is caused by the protozoan Trypanosoma cruzi, is endemic to Latin America and mainly affects low-income populations. Chemotherapy is based on two nitrocompounds, but their reduced efficacy encourages the continuous search for alternative drugs. Our group has characterised the trypanocidal effect of naphthoquinones and their derivatives, with naphthoimidazoles derived from β-lapachone (N1, N2 and N3) being the most active in vitro. OBJECTIVES In the present work, the effects of N1, N2 and N3 on acutely infected mice were investigated. METHODS in vivo activity of the compounds was assessed by parasitological, biochemical, histopathological, immunophenotypical, electrocardiographic (ECG) and behavioral analyses. FINDINGS Naphthoimidazoles led to a decrease in parasitaemia (8 dpi) by reducing the number of bloodstream trypomastigotes by 25-50% but not by reducing mortality. N1 protected mice from heart injury (15 dpi) by decreasing inflammation. Bradycardia was also partially reversed after treatment with N1 and N2. Furthermore, the three compounds did not reverse hepatic and renal lesions or promote the improvement of other evaluated parameters. MAIN CONCLUSION N1 showed moderate trypanocidal and promising immunomodulatory activities, and its use in combination with benznidazole and/or anti-arrhythmic drugs as well as the efficacy of its alternative formulations must be investigated in the near future.

Chagas congénito en atención primaria de la salud en la Provincia de Santa Fe / Congenital Chagas disease in primary health care in Santa Fe province

Actualmente, la transmisión transplacentaria es la vía más frecuente de infección por Trypanosoma cruzi. El diagnóstico y tratamiento temprano de hijos infectados evita el riesgo de desarrollar miocardiopatía y las niñas dejan de ser potenciales fuentes de transmisión congénita. En este estudio se evaluó el seguimiento de hijos de mujeres infectadas por T. cruzi en Centros de Salud de la provincia de Santa Fe. Se estudiaron 19 madres y sus 51 hijos. 45% (23/51) de los hijos no habían sido estudiados previamente, y de éstos 21/23 resultaron negativos mientras que dos niñas de 3 y 7 años estaban infectadas. Los 28 niños restantes ya habían sido estudiados en los Centros de Salud, siendo positivas dos gemelas de 22 meses y una niña de 9 años; los otros 25/28 hijos no estaban infectados. Un 47% (9/19) de las madres tenían como único antecedente la serología materna positiva, y de las 4 mujeres que transmitieron la infección, tres pertenecían a este grupo. La edad promedio de diagnóstico fue: 20±6 años en las madres y 7,4±6,7 años en los hijos. Se requieren estrategias sanitarias que favorezcan el estudio para la infección por T. cruzi en mujeres antes del embarazo y el seguimiento de todos los hijos para no perder la oportunidad de tratamiento

Transplacental transmission is currently the most frequent route of infection by Trypanosoma cruzi. Early diagnosis and treatment of infected children avoids the risk of developing cardiomyopathy, and girls are no longer potential sources of congenital transmission. This study evaluated the follow-up of children of women infected with T. cruzi in Primary Care Centres of the province of Santa Fe. Nineteen mothers and their 51 children were studied. Among the 51 children, 23 had no previous diagnosis (45%). Of these, 21 were negative while 2 girls, ages 3 and 7, were infected. The remaining 28 children already had a diagnosis at the Health Centres, with 2 twins of 22 months and a 9-year-old girl who were positive; the other 25 children were not infected. Among the 19 mothers, 9 (47%) had the positive maternal serology as the only antecedent. Of the 4 women who transmitted the infection, 3 belonged to this group. The average age of diagnosis was: 20 ± 6 years in mothers and 7.4 ± 6.7 years in children. Health strategies are required to promote the detection of infected women before pregnancy and the monitoring of all children so as not to miss the opportunity for treatment

Characterization of adverse reactions to benznidazole in patients with Chagas disease in the Federal District, Brazil

Abstract INTRODUCTION: Benznidazole is used for treating Chagas disease (CD). This cross-sectional study aimed to characterize the adverse drug reactions (ADRs) of benznidazole at a public hospital in Brazil's Federal District. METHODS: Medical records were analyzed and ADRs were categorized by type, intensity, seriousness, and causality. RESULTS: Of the 62 patients who started benznidazole treatment for CD, 41 (66%) presented with 105 ADRs; 23 (37%) discontinued the treatment. Most reactions were classified as probable (81%), severe (63%), serious (67%), and dose-dependent (56%). CONCLUSIONS: The high incidence of ADRs because of treatment withdrawal revealed the need for safer alternatives for CD treatment.

Cardiac Evaluation in the Acute Phase of Chagas' Disease with Post-Treatment Evolution in Patients Attended in the State of Amazonas, Brazil / Avaliação Cardíaca na Fase Aguda da Doença de Chagas com Evolução Pós-Tratamento em Pacientes Atendidos no Estado do Amazonas, Brasil

Abstract Background: In the past two decades, a new epidemiological profile of Chagas' disease (CD) has been registered in the Brazilian Amazon where oral transmission has been indicated as responsible for the increase of acute cases. In the Amazonas state, five outbreaks of acute CD have been registered since 2004. The cardiac manifestations in these cases may be characterized by diffuse myocarditis, with alteration in the electrocardiogram (ECG) and transthoracic echocardiogram (TTE). Objective: To perform a cardiac evaluation in autochthonous patients in the acute phase and at least one year after submitted to treatment for acute CD and evaluate the demographic variables associated with the presence of cardiac alterations. Methods: We evaluated patients diagnosed with acute CD through direct parasitological or serological (IgM) methods from 2007 to 2015. These patients were treated with benznidazole and underwent ECG and TTE before and after treatment. We assumed a confidence interval of 95% (CI 95%, p < 0.05) for all variables analyzed. Results: We observed 63 cases of an acute CD in which oral transmission corresponded to 75%. Cardiac alterations were found in 33% of the cases, with a greater frequency of ventricular repolarization alteration (13%), followed by pericardial effusion (10%) and right bundle branch block and left anterior fascicular block (2%). The follow-up occurred in 48 patients with ECG and 25 with TTE for a mean period of 15.5 ± 4.1 months after treatment. Of these, 8% presented normalization of the cardiac alterations in ECG, 62.5% remained with the normal exams. All of the patients presented normal results in TTE in the post-treatment period. As for the demographic variables, isolated cases presented more cardiac alterations than outbreaks (p = 0.044) as well as cases from Central Amazonas mesoregion (p = 0.020). Conclusions: Although cardiac alterations have not been frequent in most of the studied population, a continuous evaluation of the clinical-epidemiological dynamics of the disease in the region is necessary in order to establish preventive measures.

Resumo Fundamento: Nas últimas duas décadas, um novo perfil epidemiológico da Doença de Chagas (DC) foi registrado na Amazônia brasileira, onde a transmissão oral foi indicada como responsável pelo aumento dos casos agudos. No estado do Amazonas, foram registrados cinco surtos da doença desde 2004. As manifestações cardíacas nesses casos podem ser caracterizadas por miocardite difusa, com alteração nos resultados eletrocardiograma (ECG) e ecocardiografia transtorácica (ETT). Objetivo: avaliar parâmetros cardíacos em pacientes autóctones com DC na fase aguda e em um ano ou mais após tratamento, e avaliar as variáveis demográficas associadas com a presença de alterações cardíacas. Métodos: Avaliamos os pacientes diagnosticados com DC aguda por método direto parasitológico e exame sorológico (IgM) entre 2007 e 2015. Os pacientes foram tratados com benzonidazol e submetidos à ECG e ETT antes e após tratamento. Assumimos um intervalo de confiança de 95% (p < 0,05) para todas as variáveis analisadas. Resultados: Observamos 63 casos de DC aguda em que a transmissão oral ocorreu em 75% dos casos. Alterações cardíacas foram encontradas em 33% dos casos, com maior frequência de repolarização ventricular (13%), seguida de derrame pericárdico (10%), e bloqueio do ramo direito e bloqueio fascicular anterior esquerdo (2%). O acompanhamento foi realizado com 48 pacientes com ECG e 25 com ETT por um período médio de 15,5±4,1 meses após o tratamento. Desses pacientes, observou-se normalização das alterações eletrocardiográficas em 8% dos pacientes, e 62,5% continuaram com os parâmetros normais. Todos os pacientes apresentaram resultados da ETT normais no período pós-tratamento. Quanto às variáveis demográficas, os casos isolados apresentaram mais alterações cardíacas em comparação aos casos de surtos (p=0,044) e os casos identificados na mesorregião do Amazonas Central (p = 0,020). Conclusões: Apesar de as alterações cardíacas não terem sido frequentes na maioria da população do estudo, é necessária uma avaliação contínua da dinâmica clínica-epidemiológica da doença na região para se estabelecer medidas preventivas.

In vitro genotoxicity of nitroimidazoles as a tool in the search of new trypanocidal agents

BACKGROUND Only benznidazole (Bnz) (1) and nifurtimox (Nfx) (2) are licensed for the treatment of Chagas disease although their safety and efficacy profile are far from ideal. Farmanguinhos from Fiocruz has developed seven nitroimidazole compounds (4-10) analogs of megazol (3). OBJECTIVES To evaluate whether the genotoxic effect of 3 was abolished in the seven nitroimidazoles (4-10) analogs using the in vitro alkaline comet assay (CA) and the in vitro cytokinesis-block micronucleus assay (CBMN) in whole human blood cells (WHBC) and correlate this effect with their trypanocidal activity using bloodstream trypomastigote forms of Trypanosoma cruzi. METHODS The toxicity of 3-10 to WHBC in the in vitro CA was determined using the fluorescein diacetate/ethidium bromide assay. DNA damage in the in vitro CA was evaluated according to tail size in four classes (0-3) and methyl methane-sulfonate (MMS) was used as a positive control. The cytotoxicity of 3-10 to WHBC in the CBMN was measured using the cytokinesis-block proliferation index and the replication index. The number of the micronucleate cells in 2,000 binucleate cells by experimental group was determined. Mitomycin C and N-deacetyl-N-methylcolchicine were used as positive controls. FINDINGS Compound 3 showed a significant DNA strand break effect through the in vitro CA and highly significant clastogenic and/or aneugenic effect in the CBMN. Compounds 5, 6, 8, 9 and 10 showed negative results in the CBMN and positive results in the in vitro CA, while the inverse effect was observed for 4 and 7. MAIN CONCLUSIONS Compound 10 was the most promising to proceed with the development as a drug candidate in the treatment of Chagas disease showing absence of chromosomal cytogenetic damage and high activity against T. cruzi, about two times higher than 3 and the clinical drug 1.

Reactivation of Chagas disease in a heart transplant patient infected by sylvatic trypanosoma cruzi discrete typing unit I

Abstract Heart transplantation is an effective treatment for Chagas disease patients with severe cardiomyopathy. However, Trypanosoma cruzi reactivation is of great concern. The T. cruzi parasite is classified into six discrete typing units (DTUs identified as TcI-TcVI). It is unknown whether there is an association between T. cruzi genetic lineages and the different clinical manifestations of the disease. We report the case of a 51-year-old man who received a heart transplantation and presented with a reactivation of the disease. The molecular characterization of the parasite showed that the reactivation was related to specific infection by a DTU I (TcISYL) parasite.

First report of treatment failure in a patient with cutaneous leishmaniasis infected by Leishmania (Viannia) naiffi carrying Leishmania RNA virus: a fortuitous combination?

Abstract We report the case of a 32-year-old man from Rio de Janeiro, who was infected in the Amazon region of Brazil by Leishmania (Viannia) naiffi. Generally, patients with L. naiffi cutaneous leishmaniasis exhibit a good therapeutic response to either pentavalent antimonials or pentamidine. However, after pentamidine treatment, this patient's infection evolved to therapeutic failure. To understand this clinical outcome, we investigated the presence of the Leishmania RNA virus (LRV) in parasites isolated from the cutaneous lesion; herein, we discuss the possible association between a poor response to pentamidine therapy and the presence of the LRV.

Chagas cardiomyopathy associated with serological cure after trypanocidal treatment during childhood

Abstract Chagas disease is a chronic parasitological disease, which could cause cardiac manifestations in approximately one-third of affected individuals. Benznidazole and nifurtimox are used to treat this parasitological infection caused by Trypanosoma cruzi. Conventionally, the criterion for cure is consistently negative serological tests after treatment. We report a case of a patient who was treated when she was 13 years old and achieved T. cruzi negative seroconversion but developed Chagas disease cardiomyopathy as an adult.

Therapeutic drug monitoring of benznidazole and nifurtimox: a systematic review and quality assessment of published clinical practice guidelines

Abstract The pharmacological management of adults with chronic-phase Chagas disease is challenging despite it being the recent focus of extensive research. One of the challenges in the current clinical practice guidelines (CPGs) landscape is the existence of non-evidence-based recommendations for the use of laboratory tests in treatment monitoring. This study aimed to systematically assess the quality and consistency of recommendations of CPGs on the pharmacological management of adults with chronic-phase Chagas disease. Systematic literature searches were conducted in MEDLINE, EMBASE, SciELO and Google to identify all published CPGs relevant to the pharmacological management of Chagas disease, between January 2010 and March 2016. Three independent reviewers assessed the quality of each CPG using the Appraisal of Guidelines Research and Evaluation (AGREE) II instrument. A total of five CPGs were included and the overall quality of the guidelines for therapeutic drug monitoring of Chagas disease was moderate-to-low. There was considerable variation in the quality of the CPGs across the AGREE II domains. The domains of scope/purpose, stakeholder involvement, and clarity of presentation were rated well, and the domains of applicability and editorial independence received poor ratings. This review showed that the methodological quality of CPGs for Chagas disease was generally inappropriate, and there was no explicit link between the best available evidence and current recommendations.

Dipyridamole potentiated the trypanocidal effect of nifurtimox and improved the cardiac function in NMRI mice with acute chagasic myocarditis

BACKGROUND As chronic Chagas disease does not have a definitive treatment, the development of alternative therapeutic protocols is a priority. Dipyridamole (DPY) is an alternative to counteract the pathophysiological phenomena involved in Chagas cardiomyopathy. OBJECTIVE To evaluate the therapeutic efficacy of DPY associated with nifurtimox (Nfx) in epimastigote axenic cultures and in mice with acute Chagas disease. METHODS NMRI adult male mice were divided into nine groups: three healthy and six Trypanosoma cruzi-infected groups. Mice received vehicle, Nfx or DPY, alone or combined. The doses assayed were Nfx 10 and 40 mg/kg and DPY 30 mg/kg. The treatment efficacy was evaluated by clinical, electrocardiographic, parasitological, biochemical and histopathological methods. FINDINGS In vitro, DPY and Nfx had a trypanocidal effect with IC50 values of 372 ± 52 and 21.53 ± 2.13 µM, respectively; DPY potentiated the Nfx effect. In vivo, Nfx (40 mg/kg) with or without DPY had a therapeutic effect, which was reflected in the 84-92% survival rate and elimination of parasitaemia and heart tissue amastigotes. Nfx (10 mg/kg) had a subtherapeutic effect with no survival and persistence of amastigotes, inflammation and fibrosis in heart tissue; adding DPY increased the survival rate to 85%, and all tested parameters were significantly improved. MAIN CONCLUSION DPY has a trypanocidal effect in vitro and enhances the Nfx therapeutic effect in an in vivo murine model.

Pharmacotherapeutic follow-up of patients with Chagas disease using benznidazole: drug-related problems and pharmaceutical interventions

Abstract INTRODUCTION Benznidazole (BNZ) is a drug available for the etiological treatment of Chagas disease. However, this drug is toxic and has a limited effectiveness on the chronic phase of this disease, often leading to poor treatment adherence. METHODS: This is a descriptive and exploratory study conducted at the Pharmaceutical Care Service for Chagas disease patients of the Federal University of Ceará. Drug-related problems (DRPs) and pharmaceutical interventions (PIs) were classified according to the Second Consensus of Granada. RESULTS: The average age of patients with Chagas disease was 62 years, with the majority residing in the Ceará countryside (86.7%), and having low education levels (63.3% with elementary school education). Regarding family income, most patients belonged to a household that earned ≤1-2 times the minimum wage per month. Approximately 73% of these patients complied with the BNZ treatment, and nearly 7% underwent therapy interruption after medical evaluation. A total of 189 DRPs were identified, of which 51.9% (n=98) were classified as potential, and 48.1% (n=91) as actual. The most frequent DRPs were related to safety (qualitative safety; n=70; 37%), necessity (non-adherence; n=52; 27.5%), and effectiveness (qualitative effectiveness/non-optimal drug selection; n=45; 23.8%). Among the 216 PIs conducted, the majority were related to patient education (n=168; 77.8%) and pharmacological strategy (n=42; 19.4%). CONCLUSIONS: This study indicates the need for pharmacotherapeutic monitoring in patients with Chagas because of the high number of therapeutic interventions, DRPs (approximately 3 DRPs/patient), BNZ adherence, and polypharmacy.

Chagas disease: review of needs, neglect, and obstacles to treatment access in Latin America

Abstract After more than one century since its discovery, Chagas disease is still extremely prevalent in 21 Latin American countries. Chagas disease is one of the most concerning public health problems in Latin America; the overall cost of CD treatment is approximately 7 billion United States dollars per year and it has a strong social impact on populations. Little progress has been made regarding the access to diagnosis and treatment at the primary health care level, calling into question the current policies to ensure the right to health and access to essential medications. In this article, diverse dimensions of access to treatment for Chagas disease are reviewed, illustrating the present state of benznidazole medication in relation to global production capacity, costs, and needs. The findings are based on an investigation requested by Médecins Sans Frontières Brazil through a consultancy in 2015, aiming to estimate the current costs of benznidazole production.

Chronic Chagas cardiomyopathy: a review of the main pathogenic mechanisms and the efficacy of aetiological treatment following the BENznidazole Evaluation for Interrupting Trypanosomiasis (BENEFIT) trial

Chagas cardiomyopathy is the most frequent and most severe manifestation of chronic Chagas disease, and is one of the leading causes of morbidity and death in Latin America. Although the pathogenesis of Chagas cardiomyopathy is incompletely understood, it may involve several mechanisms, including parasite-dependent myocardial damage, immune-mediated myocardial injury (induced by the parasite itself and by self-antigens), and microvascular and neurogenic disturbances. In the past three decades, a consensus has emerged that parasite persistence is crucial to the development and progression of Chagas cardiomyopathy. In this context, antiparasitic treatment in the chronic phase of Chagas disease could prevent complications related to the disease. However, according to the results of the BENEFIT trial, benznidazole seems to have no benefit for arresting disease progression in patients with chronic Chagas cardiomyopathy. In this review, we give an update on the main pathogenic mechanisms of Chagas disease, and re-examine and discuss the results of the BENEFIT trial, together with its limitations and implications.

Adverse systemic reaction to benznidazole

Abstract Benznidazole, drug of choice for Chagas disease (CD), has been associated with a high incidence of adverse reactions that can become serious, necessitating discontinuation of the drug. We describe the case of a Bolivian patient living in Spain for 9 years, who, following treatment with benznidazole for CD in indeterminate chronic phase, presented with fever, skin lesions, digestive symptoms, general malaise, and laboratory abnormalities. After the discontinuation of benznidazole and, the intake of antihistamines and systemic corticosteroids, the patient presented a complete resolution of the symptoms. Optimization of dose strategies and development of more effective, and better-tolerated drugs is advisable.

Actividad tripanocida de Piper solmsianum C. DC. sobre formas epimastigota y tripomastigota de Trypanosoma cruzi / Trypanocidal activity of Piper solmsianum C. DC. against epimastigote and trypomastigote forms of Trypanosoma cruzi

Introducción: la infección por Trypanosoma cruzi, conocida como enfermedad de Chagas, es un problema importante de salud pública en países de América Central y Sudamérica.Objetivo: evaluar la actividad de extractos crudos de acetato de etilo de plantas in vitro de 6-8 meses y 10-12 meses de edad, de tallos leñosos y hojas de plantas silvestres maduras y el lignano tetrahidrofurano grandisina, aislados de Piper solmsianum, sobre las formas epimastigota y tripomastigota de T. cruzi in vitro.Métodos: en la evaluación del efecto de diversos extractos crudos de acetato de etilo y grandisina de P. solmsianum, sobre la viabilidad de las formas epimastigota y tripomastigota de T. cruzi, se utilizó el método MTT (3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium bromuro).Resultados: en la forma epimastigota, el mejor resultado en la inhibición del crecimiento fue obtenido con 50 µg/mL de extracto de tallo y en la forma tripomastigota con 25 y 50 µg/mL de grandisina y plantas in vitro de 6-8 meses de edad, respectivamente. En todos los casos los valores de inhibición oscilaron entre 86 a 96 por ciento. Plantas in vitro de 6-8 meses de edad y grandisina fueron más activas sobre las formas epimastigota y tripomastigota de T. cruzi con valores de CI50 de 0,018 y 0,360 µg/mL, respectivamente.Conclusiones: se demuestra la actividad tripanocida de extractos de plantas silvestres y plantas in vitro de P. solmsianum(AU)

Introduction: the infection by Trypanosoma cruzi, known as Chagas' disease, poses a major public health problem in Central and South America countries.Objective: to evaluate the activity of crude ethyl acetate extracts from in vitro plants of 6-8 and 10-12 months of age, stem barks and mature wild plant leaves and tetrahydrofuran lignin grandisin isolated from Piper solmsianum against the epimastigote and trypomastigote forms of T. cruzi in vitro.Methods: in the evaluation of the effect of various crude ethyl acetate extracts and grandisin from P. solmsianum on the viability of epimastigote and trypomastigote forms of T. cruzi, the MTT method (3-(4,5-dimethylthiazol-2-il)-2,5-diphenyltetrazolium bromide) was used.Results: in the epimastigote form, the best results in growth inhibition was obtained with 50 µg/mL of stem extract, and in the trypomastigote form, with 25 and 50 µg/mL of grandisin and 6-8 months-old in vitro plants, respectively. The inhibition values in all cases ranged from 86 to 96 percent. 6-8 months old in vitro plants and grandisin were found to be active against the epimastigote and trypomastigote forms of T. cruzi with IC50 of 0.018 µg/mL and 0.360 µg/mL, respectively.Conclusions: the trypanocidal activity of extracts from wild plants and in vitro plants of P. solmsianum was proved(AU)

High seroconversion rates in Trypanosoma cruzi chronic infection treated with benznidazole in people under 16 years in Guatemala

Abstract INTRODUCTION: Geographical, epidemiological, and environmental differences associated with therapeutic response to Chagas etiological treatment have been previously discussed. This study describes high seroconversion rates 72 months after benznidazole treatment in patients under 16 years from a project implemented by Doctors without Borders in Guatemala. METHODS: An enzyme-linked immunosorbent assay was used to detect Trypanosoma cruzi IgG antibodies in capillary blood samples from patients 72 months after treatment. Fisher's exact test was used to establish association between characteristics, such as sex, age, and origin of patients, and final seroconversion. Kappa index determined concordance between laboratory tests. The level of significance was set to 5%. RESULTS: Ninety-eight patients, aged 6 months to 16 years, were available for follow-up. Sex and origin were not associated with seroconversion. Individuals older than 13 were more prone to maintain a positive result 72 months after treatment, although results were not highly significant. Laboratory tests presented elevated Kappa concordance (95% CI) = 0.8290 (0.4955-1), as well as high (97%) seroconversion rates. CONCLUSIONS: The high seroconversion rate found in this study emphasizes the importance of access to diagnosis, treatment, and follow-up of individuals affected by Chagas disease. Moreover, it contradicts the idea that it is not possible to achieve a cure with the currently available drugs. This study strongly supports expanding programs for patients infected with T. cruzi in endemic and non-endemic countries.