Enfermedad de chagas congénito: presentación de caso clínico / Congenital chagas disease: case report

El agente etiológico de la enfermedad de Chagas es un protozoario parásito (Tripano-soma Cruzi) que causa una infección aguda y crónica, en humanos. La extensión del daño varía de acuerdo a las cepas parasita-rias y características individuales del hués-ped; puede causar incapacidad y muerte. Han sido descritas diferentes vías de infec-ción: vectorial, transfusional, accidental, digestiva y congénita. Esta última vía de la infección depende de dos indicadores bási-cos, la prevalencia de gestantes chagásicas e incidencia de la transmisión vertical. El diagnóstico presenta un desafío en aquellos lugares del país en donde, si bien la enfer-medad es considerada endémica, no se realiza actualmente el screening obligatorio en la embarazada. Es importante saber que el tratamiento antes del primer año de vida tiene una excelente respuesta y evita secue-las crónicas que pueden ser invalidantes en etapa adulta...(AU)

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.

Terapia de Resgate com Nifurtimox e Dipiridamol na Miocardite Chagásica Aguda Grave com Insuficiência Cardíaca em Camundongos NMRI / Rescue Therapy with Nifurtimox and Dipyridamole for Severe Acute Chagas Myocarditis with Congestive Heart Failure in NMRI Albino Mice

Fundamento: A doença de Chagas é um problema de saúde global, sendo necessário o desenvolvimento de novos protocolos terapêuticos. Nosso grupo demonstrou recentemente que o nifurtimox associado ao dipiridamol tem efeitos curativos em camundongos com doença de Chagas aguda. Neste estudo, avaliamos o efeito deste protocolo terapêutico em camundongos chagásicos com insuficiência cardíaca. Objetivo: Avaliar se o nifurtimox e o dipiridamol são úteis no tratamento de resgate em camundongos com miocardite chagásica aguda com insuficiência cardíaca. Métodos: Foram divididos em três grupos 42 camundongos com miocardite chagásica aguda e insuficiência cardíaca congestiva: Controle Chagas (n = 11); Nif-Dip, tratados com nifurtimox e dipiridamol (n = 14); e Nif-Dip-Insuficiência Cardíaca, tratados com nifurtimox e dipiridamol, associados com digoxina, furosemida e captopril (n = 17). As doses de nifurtimox e dipiridamol foram de 40 e 30mg/kg/dia, respectivamente, durante 6 semanas. Os camundongos foram submetidos a avaliações clínicas, eletrocardiográficas, hemoparasitológicas e histopatológicas. Resultados: Observou-se menor mortalidade no Grupo Nif-Dip (n = 4; 28,57%) em relação ao Controle Chagas (n = 6; 54,54%) e ao Nif-Dip-Insuficiência Cardíaca (n = 9; 52,9%). Clinicamente, os camundongos tratados com nifurtimox e dipiridamol aumentaram o peso corporal e melhoraram a insuficiência cardíaca, sem mostrar esplenomegalia. Nestes grupos, foram erradicadas as parasitemias e os parasitas teciduais; a fibrose, a miocitólise, o infiltrado de células inflamatórias e os mastócitos diminuíram. Os distúrbios de repolarização, os intervalos QRS e o QT prolongados, o aumento da amplitude da onda S e a dissociação atrioventricular foram revertidos pelo tratamento. Conclusão: O tratamento com nifurtimox e dipiridamol pode ser usado no resgate em camundongos com doença chagásica aguda grave, já que o nifurtimox teve atividade tripanocida, e o dipiridamole potenciou seu efeito. O dipiridamol seria útil na insuficiência cardíaca chagásica

Background: Chagas disease is a global health problem; therefore, the development of new therapeutic protocols is necessary. Our group recently demonstrated that nifurtimox associated with dipyridamole has curative effects in mice with acute Chagas disease. In this study, we assess the effect of this therapeutic protocol in chagasic mice with heart failure. Objective: To evaluate whether nifurtimox and dipyridamole are useful to rescue mice with severe acute chagasic myocarditis with heart failure. Methods: 42 mice with acute chagasic myocarditis and congestive heart failure were divided into three groups: control chagas (n = 11), Nif-Dip treated with nifurtimox and dipyridamole (n = 14) and Nif-Dip-heart failure treated with nifurtimox and dipyridamole associated with digoxin, furosemide, and captopril (n = 17). Nifurtimox and dipyridamole doses were 40 and 30 mg/kg/day, respectively, for 6 weeks. Mice underwent clinical, electrocardiographic, hemoparasitological and histopathological assessments. Results: Lower mortality in Nif-Dip (28.57%; n = 4) compared to control chagas (54.54%; n = 6) and Nif-Dip-heart failure (52.9%; n = 9) was observed. Clinically, nifurtimox and dipyridamole-treated mice increased body weight and improved heart failure without splenomegaly. In these groups, parasitemia and tissue parasites were eradicated; fibrosis, myocytolysis, inflammatory cell infiltrate and mast cells decreased. Repolarization disorders, prolonged QRS and QT intervals, increase of S wave amplitude and atrioventricular dissociation were reversed by the treatment. Conclusion: Nifurtimox with dipyridamole can rescue NMRI mice from severe acute chagas disease, as nifurtimox showed trypanocidal activity and dipyridamole potentiated its effect. Dipyridamole would be useful in chagasic heart failure

Experiencia terapéutica en un centro para la enfermedad de Chagas / Therapeutic experience in a Chagas disease center

American Trypanosomiasis or Chagas Disease is a major public health problem, endemic in the American continent since prehistoric times. Its natural course is towardschronicity in the immunocompetent host, often leading to severe cardiopathy or bowelinvolvement. Pharmacologic therapy is restricted to two drugs and only one of themis currently available in Chile. Both have poor effectiveness in the chronic stages ofthe disease and cause frequent adverse reactions. Many physicians avoid their use,despite published evidences about the usefulness. We herein report the experienceof our Center in the treatment of Chronic Chagas Disease in adults using the drugnifurtimox, emphasizing its degree of acceptability and its secondary effects.

Evaluation of the ELISA-F29 test as an early marker of therapeutic efficacy in adults with chronic Chagas disease / Avaliação do tratamento tripanossomicida em coorte de adultos chagásicos crônicos através de técnicas sorológicas convencionais e ELISA-F29

This work compared the time at which negative seroconversion was detected by conventional serology (CS) and by the ELISA-F29 test on a cohort of chronic chagasic patients treated with nifurtimox or benznidazole. A retrospective study was performed using preserved serum from 66 asymptomatic chagasic adults under clinical supervision, and bi-annual serological examinations over a mean follow-up of 23 years. Twenty nine patients received trypanocide treatment and 37 remained untreated. The ELISA-F29 test used a recombinant antigen which was obtained by expressing the Trypanosoma cruzi flagellar calcium-binding protein gene in Escherichia coli. Among the untreated patients, 36 maintained CS titers. One patient showed a doubtful serology in some check-ups. ELISA-F29 showed constant reactivity in 35 out of 37 patients and was negative for the patient with fluctuating CS. The treated patients were divided into three groups according to the CS titers: in 13 they became negative; in 12 they decreased and in four they remained unchanged. ELISA-F29 was negative for the first two groups. The time at which negativization was detected was significantly lower for the ELISA-F29 test than for CS, 14.5 ± 5.7 and 22 ± 4.9 years respectively. Negative seroconversion was observed in treated patients only. The results obtained confirm that the ELISA-F29 test is useful as an early indicator of negative seroconversion in treated chronic patients.

Este trabalho comparou os tempos de soroconversão negativos obtidos pela sorologia convencional (CS) e teste ELISA-F29 em uma coorte de pacientes chagásicos crônicos tratados com nifurtimox ou benznidazol. Um estudo retrospectivo foi realizado com soro preservado de 66 adultos chagásicos assintomáticos com acompanhamento clínico e sorológico semestral ao longo de um seguimento médio de 23 anos. 29 pacientes receberam tratamento tripanossomicida e 37 outras permaneceram sem tratamento. O teste ELISA-F29 usou um antígeno recombinante obtido por expressão do gene de uma proteína flagelar de Trypanosoma cruzi de ligação de cálcio em Escherichia coli. Entre os pacientes não tratados, 36 mantiveram os títulos da CS. Um paciente apresentou sorologia duvidosa em alguns controles. ELISA-F29 apresentou reatividade constante em 35/37 e foi negativo no paciente com CS flutuante. Os pacientes tratados foram agrupados de acordo com os títulos da CS, em três grupos: 13 tornaram-se negativos, 12 diminuíram e quatro permaneceram inalterados. ELISA-F29 foi negativo nos dois primeiros grupos. O tempo de negativização foi significativamente menor para o teste ELISA-F29 do que para CS (14,5 ± 5,7 e 22 ± 4,9 anos, respectivamente). A soroconversão negativa foi observada somente nos pacientes tratados. Os resultados obtidos confirmam que o teste ELISA-F29 é útil como um indicador precoce de soronegativação em pacientes crônicos tratados.

Eficacia de nifurtimox para el tratamiento de pacientes con enfermedad de Chagas crónica / Efficacy of nifurtimox for the treatment of chronic Chagas disease

Background: Most Chagas patients belong to the chronic indeterminate stage, in which pharmacological treatment has an inconclusive outcome. Objective: To evaluate the efficacy of nifurtimox treatment in chronic asymptomatic Trypanosoma cruzi infection. Methods: We performed a systematic review and meta-analysis of electronically published literature, with no language, type of study, age or gender restrictions, until September 2010. Studies of chronic asymptomatic Chagas disease patients treated exclusively with nifurtimox were included in the analysis. Treatment efficacy was evaluated using parasitological or serological parameters. Results: Of 463 identified studies, 7 were finally selected: 6 observational studies and 1 randomized clinical trial; 4 of the studies were in adults, 3 in children < 14 years. In 6 studies, outcomes were defined by serological techniques. Summary estimate (log odds) was 0.37 (CI9 -1.32 - 2.07). Conclusions: The analyzed studies gave discordant results. Those might be explained by differences in the populations studied, follow-up periods, diagnostic techniques, and sample size. More studies are necessary to obtain conclusive results about treatment efficacy of nifurtimox in this clinical phase of T. cruzi infection.

Introducción: La mayoría de los pacientes con enfermedad de Chagas se encuentran en fase crónica indeterminada donde los resultados de tratamiento farmacológico no han sido concluyentes. Objetivo: Evaluar la evidencia que apoya la eicacia del tratamiento con nifurtimox en la infección crónica por Trypanosoma cruzi asintomática. Método: Revisión sistemática y meta-análisis de literatura publicada en forma electrónica, sin restricción de lenguaje, tipo de estudio, edad y género, hasta septiembre de 2010. Se incluyeron estudios de pacientes con enfermedad de Chagas crónica asintomáticos que recibieron tratamiento exclusivo con nifurtimox. La eicacia del tratamiento fue evaluada mediante métodos parasitológicos o serológicos. Resultados: Se identiicaron 463 estudios primarios seleccionando inalmente siete: seis observacionales y un ensayo clínico randomizado; cuatro en pacientes adultos y tres en niños bajo14 años de edad. En seis estudios los resultados se midieron mediantes técnicas serológicas. La medida resumen (log de la chance) fue de 0,37 (IC95% -1,32 -2,07). Conclusiones: Los resultados son discordantes. La incertidumbre se maniiesta por las diferencias en las poblaciones estudiadas, periodos de seguimiento, técnicas diagnósticas y tamaño de las muestras. Es necesario realizar nuevos estudios que consideren las fuentes de incertidumbre para obtener resultados concluyentes sobre la eicacia del nifurtimox en esta fase clínica de la infección por T. cruzi.

Chagas disease: Present status of pathogenic mechanisms and chemotherapy

There are approximately 7.8 million people in Latin America, including Chile, who suffer from Chagas disease and another 28 million who are at risk of contracting it. Chagas is caused by the flagellate protozoan Trypanosoma cruzi. It is a chronic disease, where 20 percent-30 percent of infected individuals develop severe cardiopathy, with heart failure and potentially fatal arrhythmias. Currently, Chagas disease treatment is more effective in the acute phase, but does not always produce complete parasite eradication during indeterminate and chronic phases. At present, only nifurtimox or benznidazole have been proven to be superior to new drugs being tested. Therefore, it is necessary to find alternative approaches to treatment of chronic Chagas. The current treatment may be rendered more effective by increasing the activity of anti-Chagasic drugs or by modifying the host's immune response. We have previously shown that glutathione synthesis inhibition increases nifurtimox and benznidazole activity. In addition, there is increasing evidence that cyclooxygenase inhibitors present an important effect on T. cruzi infection. Therefore, we found that aspirin reduced the intracellular infection in RAW 264.7 cells and, decreased myocarditis extension and mortality rates in mice. However, the long-term benefit of prostaglandin inhibition for Chagasic patients is still unknown.

Trypanocide treatment among adults with chronic Chagas disease living in Santa Fe city (Argentina), over a mean follow-up of 21 years: parasitological, serological and clinical evolution

The efficacy of treatment with nifurtimox and/or benznidazole among adults with chronic Chagas disease with no previous electrocardiographic disturbances was evaluated over a mean follow-up of 21 years, by means of conventional serology, xenodiagnosis, clinical examination, electrocardiograms and chest X-ray. One hundred and eleven patients, between 17 and 46 years old, were studied: 54 underwent treatment (nifurtimox 27, benznidazole 27) and 57 remained untreated (control group). Xenodiagnosis was performed on 65 percent of them: 36/38 of the treated and 9/34 of the untreated patients had previous positive xenodiagnosis. Post-treatment, 133 xenodiagnoses were performed on 41 patients, all resulting negative. In the control group, 29 xenodiagnoses were performed on 14 patients; 2 resulted positive. Sera stored during the follow-up were simultaneously analyzed through conventional serology tests (IHA; DA-2ME; IIF). The serological evolution in the treated group was: a) 37 percent underwent negative seroconversion (nifurtimox 11, benznidazole 9); b) 27.8 percent decreased titers (nifurtimox 9, benznidazole 6), 9 showed inconclusive final serology (nifurtimox 7, benznidazole 2); c) 35.2 percent remained positive with constant titers (nifurtimox 7; benznidazole 12). The control group conserved the initial antibody levels during the follow-up. In the clinical evolution, 2/54 (3.7 percent) of the treated and 9/57 (15.8 percent) of the untreated patients showed electrocardiographic disturbances attributable to Chagas myocardiopathy, with a statistically relevant difference (p<0.05). Treatment caused deparasitation in at least 37 percent of the chronically infected adults and a protective effect on their clinical evolution.

Avaliamos a eficácia do nifurtimox e/ou benznidazol, durante 21 anos em média, em adultos chagásicos crônicos sem alterações eletrocardiográficas iniciais, mediante sorologia convencional, xenodiagnóstico, exames clínicos, eletrocardiográficos e radiografia do tórax. Estudamos 111 pacientes (17 a 46 anos): 54 foram tratados (27 com nifurtimox e 27 com benznidazol) e 57 formaram o grupo controle. Foram submetidos ao xenodiagnóstico 65 por cento dos pacientes estudados: 36/38 tratados e 9/34 do grupo controle com xenodiagnóstico positivo prévio. Após tratamento, foram realizados 133 xenodiagnósticos em 41 pacientes, sendo todos negativos. Foram realizados 29 xenodiagnósticos em 14 pacientes do grupo controle, 2 foram positivos. A sorologia convencional foi realizada em soros estocados durante o seguimento. Evolução sorológica. Grupo tratado: a) 37 por cento negativaram (nifurtimox 11, benznidazol 9); b) 27,8 por cento diminuíram a titulação (nifurtimox 9, benznidazol 6), 9 deles apresentaram sorologia final discordante (nifurtimox 7, benznidazol 2; c) 35,2 por cento permaneceram positivos com titulação constante (nifurtimox 7, benznidazol 12). Grupo controle: conservou os níveis iniciais de anticorpos durante o seguimento. Evolução clínica: 2/54 (3,7 por cento) pacientes tratados e 9/57 não tratados apresentaram alterações eletrocardiográficas atribuíveis a miocardiopatia chagásica. Diferenças estatisticamente significantes (p<0,05). O tratamento produziu efeito de combate ao parasita em pelo menos 37 por cento dos infetados crônicos adultos e efeito protetor na evolução clínica.

Eritema nodoso como forma de reativação da doença de Chagas em transplantado cardíaco / Erythema nodoso in reactivation of Chagas' disease after cardiac transplantation

O presente caso ilustra uma forma de eritema nodoso, cujo agente foi o Trypanosoma cruzi em paciente chagásica submetida a transplante cardíaco. O diagnóstico foi firmado através do exame histopatológico de biópsia da lesão cutânea e estudo imunohistoquímico. O tratamento com nifurtimox promoveu regressão total das lesões.

Estudo longitudinal e quimioterapia específica em crianças, com doença de Chagas crônica, residentes em área de baixa endemicidade da República Argentina / Longitudinal study and specific chemotherapy in children with chronic Chagas' disease, residing in a low endemicity area of Argentina

Apresenta-se a avaliação clinicoepidemiológica de 95 crianças chagásicas crônicas em idades entre 1 e 14 anos moradoras de Santa Fé, Argentina, não tratadas e tratadas com nifurtimox ou benznidazol, com acompanhamento de até 24 anos. Todas tinham vários antecedentes de risco para transmissão do Trypanosoma cruzi: vetorial, congênito e/ou transfusão sangüínea. O diagnóstico da infecção foi feito através de sorologia convencional. O exame clínico foi complementado por eletrocardiograma, radiografias de tórax e, análise de sangue e urina para avaliação das funções hepáticas. No pós-tratamento, utilizaram-se técnicas idênticas às do diagnóstico, sendo que 33 crianças tiveram, também, avaliação parasitológica. Dentre 24 crianças não tratadas, 14 foram controlados por 8 a 24 anos e mantiveram sorologia positiva e o estado clínico inicial. Das 71 crianças tratadas, 49 tiveram acompanhamento de 4 a 24 anos: 14 mantiveram anticorpos anti-Trypanosoma cruzi; 6 resultados discordantes e 29 negativaram a sorologia. Destas, 9 apresentaram oscilações sorológicas, antes da negativação definitiva. A mediana do tempo de negativação pós-tratamento foi, respectivamente, de 3,5 e 8 anos para crianças de 1 a 6 e 7 a 14 anos. A percentagem de soronegativos diminuiu com a idade em que se medicou, desde 75 por cento em <4 anos até 43 por cento em > 9 anos. A intolerância ao tratamento foi de 3,8 por cento. Nenhuma criança modificou seu estado clínico nesta observação.

Tratamento da fase crônica da doença de Chagas com nifurtimox associado a corticóide / Treatment of chronic Chagas' disease with an association of nifurtimox and corticoid

Dez pacientes com doença de Chagas em fase crônica foram tratados durante 60 dias, com uma única exceçäo, por meio de nifurtimox (8 a 9mg/kg/dia) conjuntamente com betametasona (doses progressivamente decrescentes a partir de 9mg/dia). Houve intençäo de utilizar a atividade antiparasitária do nifurtimox paralelamente à capacidade antiinflamatória do corticóide que, pela possibilidade de acentuar a infecção, poderia facilitar a açäo do fármaco anti-Trypanosoma cruzi. Em apenas um dos casos ocorreu negatividade prolongada dos xenodiagnósticos efetuados como controles e, quanto aos demais, ficaram evidentes os insucessos terapêuticos, corroborados pela persistência da positividade das provas sorológicas. O estudo também mostrou a necessidade de adequado e duradouro seguimento pós-tratamento para a obtençäo de corretas conclusöes

Persistent infections in chronic Chagas'disease patients treated with anti-Trypanosoma cruzi nitroderivatives

We used a molecular method and demonstrated that treatment of the chronic human Trypanosoma cruzi infections with nitroderivatives did not lead to parasitological cure. Seventeen treated and 17 untreated chronic Chagas' disease patients, with at least two out of three positive serologic assays for the infection, and 17 control subjects formed the study groups. PCR assays with nested sets of T. cruzi DNA primers monitored the efficacy of treatment. The amplification products were hybridized to their complementary internal sequences. Untreated and treated Chagas' disease patients yielded PCR amplification products with T. cruzi nuclear DNA primers. Competitive PCR was conducted to determine the quantity of parasites in the blood and revealed < 1 to 75 T. cruzi/ml in untreated (means 25.83 +/- 26.32) and < 1 to 36 T. cruzi/ml in treated (means 6.45 +/- 9.28) Chagas' disease patients. The difference between the means was not statistically significant. These findings reveal a need for precise definition of the role of treatment of chronic Chagas'disease patients with nitrofuran and nitroimidazole compounds.

Evolutive behavior towards cardiomyopathy of treated (nifurtimox or benznidazole) and untreated chronic chagasic patients

The aim of this work was to compare the evolution of chronic chagasic untreated patients (UTPs) with that of benznidazole or nifurtimox-treated patients (TPs). A longitudinal study from a low endemic area (Santa Fe city, Argentina) was performed during an average period of 14 years. Serological and parasitological analyses with clinical exams, ECG and X-chest ray were carried out. At the onset, 19/198 infected patients showed chagasic cardiomyopathy (CrChM) while 179 were asymptomatic. In this latter group the frequency of CrChM during the follow-up was lower in TPs compared with UTPs (3.2 per cent vs 7 per cent). Within the CrChM group, 2/5 TPs showed aggravated myopathy whereas this happened in 9/14 UTPs. Comparing the clinical evolution of all patients, 5.9 per cent of TPs and 13 per cent of UTPs had unfavourable evolution, but the difference is not statistically relevant. Serological titers were assessed by IIF. Titers equal to or lower than 1/64 were obtained in 86 per cent of the TPs, but only in 38 per cent of UTPs. The differences were statistically significant (geometric mean: 49.36 vs. 98.2). Antiparasitic assessment of the drugs (xenodiagnosis) proved to be effective. The low sensitivity in chronic chagasic patients must be born in mind. Despite treated patients showed a better clinical evolution and lower antibody levels than untreated ones, it is necessary to carry on doing research in order to improve therapeutic guidelines, according to the risk/benefit equation and based on scientific and ethical principles.

Avaliaçäo do tratamento especifíco para Trypanosoma cruzi em crianças, na evoluçäo da fase indeterminada / Specific treatment evaluation for Trypanosoma cruzi in children, in the evolution of the indeterminate phase

Doze pacientes com idades entre 7 a 12 anos, na forma indeterminada da doença de Chagas, com sorologia e xenodiagnóstico positivos, receberam tratamento específico. Dois pacientes tomaram 7mg/kg de nifurtimox durante 60 e 90 dias e 10 usaram 5-7mg/kg de benznidazol durante 60 dias. A evoluçäo clínica foi verificada através de exame clínico, eletrocardiograma, exame radiológico contrastado do esôfago. Após o tratamento somente uma (8,3 por cento) paciente apresentou todos os exames negativos. Oito deles foram avaliados após oito anos do tratamento e 4 acompanhados durante 20 anos. Sete (58,4 por cento) permaneceram na forma indeterminada e 4 (33,3 por cento) chagásicos progrediram clinicamente para cardiopatia grau II e/ou esofagopatia, apesar do tratamento precoce. Säo necessários estudos com maior número de crianças na fase indeterminada e acompanhamento a longo prazo para se estabelecer a influência do tratamento específico na evoluçäo da doença de Chagas

Enfermedad de Chagas: diagnóstico y tratamiento etiológico / Chagas disease: etiological treatment and diagnosis

Se hace referencia a los datos clínicos más importantes en las fases aguda, intermedia y crónica de la enfermedad de Chagas. Para la confirmación por pruebas de laboratorio se sugiere realizar estas por dos o tres técnicas ya que los métodos hasta el momento tienen baja sensibilidad y especificidad. En Guatemala hay centros de referencia para diagnóstico confirmativo de la enfermedad de Chagas en las facultades de Medicina y Química y Farmacia, Escuela de Química Biolófica de la Universidad de San Carlos de Guatemala y MERTUG en la Universidad del Valle. Para el tratamiento se recomienda Nifurtimox o Benzonidazol, especialmente en las fases aguda, intermedia y crónica de menos de diez años. Es importante el manejo de la infección accidental y reactivación asociada a inmunosupresión o inmunodeficiencia

Estudio longitudinal, mediante el xenodiagnóstico, de la parasitemia en pacientes con infección por trypanosoma cruzi crónica / Longitudinal study, by means of xenodiagnosis, of parasitemia in patients with chronic trypanosoma cruzi infection

A 2-5 years follow-up of parasitemia, by the use of xenodiagnosis (XD) was carried out in nine patients with chronic T. cruzi infection who proceeded from chagasic endemic areas of Chile. The patients (mean age 55 years) were hospitalized in the chronic section of a psychiatry institution sited in a permanent triatomines free urban area. Clinical examination, x-rays images (cardiovascular, esophagus and colon) and electrocardiogram resulted normal in all the patients. Basic study unit of parasitemia was a XD box which contained 7 nymphs III of triatoma infestans which was used in a serial XD consisting in the simultaneous application of a pair of boxes a day during three consecutive days, making a total of six boxes (42 nymphs). The minimal time of duration of infection (MDI.) for each patient was estimated that this was adquired close to hospitalization. The MDI. varied between 6 and 45 years. The global positivity of XD boxes ranged between 6.3 and 84.7 percent, being three patients lower than 12 percent and six patients higher than 52 percent. In considering the yield of XD it is important to stress that during all the study of the mine patients with chronic chagasic infection 1282 XD boxes were applied resulting positive 582 (45,4 percent). At the end of the follow-up all patients received specific treatment for chagasic infection with nifurtimox at the daily dose of 10 mg/kg of body weight during 60 days. According to the result, two main conclusions arise: 1.- serial XD has a hight efficiency for detecting, evaluate and evolve parasitemia in patients with chronic chagasic infection. 2.- parasitemia may present low, medium or high levels in different individuals and has a variable and fluctuating character

Efeito protetor do nifurtimox contra a reativação parasitária em pacientes cronicamente infectados pelo Trypanosoma cruzi e tratados com corticoide em virtude de afecçoes associadas / Nifurtimox as a prophylactic drug to prevent reactivation in chronic chagasic patients treated with corticoid for associated diseases

Pacientes na fase crônica da doença de Chagas foram tratados com corticóide em virtude de afecções associadas e, a fim de tentar coibir reativação da infecção pelo Trypanosoma cruzi, houve uso concomitante do nifurtimox. Levando em conta o verificado em pesquisa anterior, quando corticóide de fato promoveu aumento da parasitemia detectada pelo xenodiagnóstico, pôde ser notado que o nifurtimox mostrou-se apto a evitar a citada acentuação parasitária, podendo tal constatação ser útil em procedimentos assistenciais, quando circunstancialmente estiverem presentes doença de Chagas e imunodepressão.

Patients in the chronic phase of Chagas' disease and receiving corticoid because of concommitant diseases were treated with nifurtimox. We proved in another paper that in the chronic phase of Chagas' disease corticoid use is associated with increased parasitemia, as evaluated by xenodiagnosis. In this study nifurtimox use prevented this increase, and we suggest that in immunocompromised patients with chronic Chagas' disease the use of this drug could be useful.