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

BACKGROUND: Chagas disease is a parasitic infection with high re-emergence rates in some Amazon regions. The main vectors of Trypanosoma cruzi are haematophagous insects, the triatomines. Only a few reports are available about the occurrence of these wild vectors and their contact with the inhabitants of the riverside regions of the Amazon. This study describes the unusual behaviour of the triatomines that have invaded the homes of the residents of Abaetetuba, the city that has the second highest number of cases of Chagas disease. METHODS: Two cross-sectional studies were conducted using sero-epidemiological surveys of the inhabitants of Abaetetuba with registered triatomine home invasions. The frequencies of the variables of interest were analysed using Epi Info version 7.2. RESULTS: In 2014 and 2017, 145 persons registered home invasions of triatomines in their domiciles and 16.55% reported having been bitten by insects. The environmental features described indicated potential conditions for the persistence of the parasite's life cycle. Of the enrolled inhabitants, 0.47% were positive for immunoglobulin G anti-T. cruzi antibodies. CONCLUSIONS: Home invasions of triatomines were confirmed in two periods, with a description of unusual behaviour for the genus Rhodnius. The use of serological surveillance in human populations at risk of this occurrence may constitute a new tool for the early detection of silent infections.

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

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

2 nd Brazilian Consensus on Chagas Disease, 2015.

Chagas disease is a neglected chronic condition with a high burden of morbidity and mortality. It has considerable psychological, social, and economic impacts. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on the articulation and strategic contribution of renowned Brazilian experts with knowledge and experience on various aspects of the disease. It is the result of a close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. It is hoped that this document will strengthen the development of integrated actions against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research .

[Brazilian Consensus on Chagas Disease, 2015]. / II Consenso Brasileiro em Doença de Chagas, 2015.

Chagas disease is a neglected chronic condition that presents high morbidity and mortality burden, with considerable psychological, social, and economic impact. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on collaboration and contribution of renowned Brazilian experts with vast knowledge and experience on various aspects of the disease. It is the result of close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. This document shall strengthen the development of integrated control measures against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research.

II Consenso Brasileiro em Doença de Chagas, 2015 / Brazilian Consensus on Chagas Disease, 2015

A doença de Chagas é uma condição crônica negligenciada com elevada carga de morbimortalidade e impacto dos pontos de vista psicológico, social e econômico. Representa um importante problema de saúde pública no Brasil, com diferentes cenários regionais. Este documento traduz a sistematização das evidências que compõe o Consenso Brasileiro de Doença de Chagas. O objetivo foi sistematizar estratégias de diagnóstico, tratamento, prevenção e controle da doença de Chagas no país, de modo a refletir as evidências científicas disponíveis. Sua construção fundamentou-se na articulação e contribuição estratégica de especialistas brasileiros com conhecimento, experiência e atualização sobre diferentes aspectos da doença. Representa o resultado da estreita colaboração entre a Sociedade Brasileira de Medicina Tropical e o Ministério da Saúde. Espera-se com este documento fortalecer o desenvolvimento de ações integradas para enfrentamento da doença no país com foco em epidemiologia, gestão, atenção integral (incluindo famílias e comunidades), comunicação, informação, educação e pesquisas.

Chagas disease is a neglected chronic condition that presents high morbidity and mortality burden, with considerable psychological, social, and economic impact. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on collaboration and contribution of renowned Brazilian experts with vast knowledge and experience on various aspects of the disease. It is the result of close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. This document shall strengthen the development of integrated control measures against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research.

2 nd Brazilian consensus on Chagas Disease, 2015

Chagas disease is a neglected chronic condition with ahigh burden of morbidity and mortality. It has considerable psychological, social, and economic impacts. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and controlof Chagas disease in the country, based on the available scientific evidence. The consensus is based on the articulation and strategic contribution of renowned Brazilian experts with knowledge and experience on various aspects of the disease. It is the result of a close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health...

In Vitro Protective Effect and Antioxidant Mechanism of Resveratrol Induced by Dapsone Hydroxylamine in Human Cells.

Dapsone (DDS) hydroxylamine metabolites cause oxidative stress- linked adverse effects in patients, such as methemoglobin formation and DNA damage. This study evaluated the ameliorating effect of the antioxidant resveratrol (RSV) on DDS hydroxylamine (DDS-NHOH) mediated toxicity in vitro using human erythrocytes and lymphocytes. The antioxidant mechanism was also studied using in-silico methods. In addition, RSV provided intracellular protection by inhibiting DNA damage in human lymphocytes induced by DDS-NHOH. However, whilst pretreatment with RSV (10-1000 µM significantly attenuated DDS-NHOH-induced methemoglobinemia, but it was not only significantly less effective than methylene blue (MET), but also post-treatment with RSV did not reverse methemoglobin formation, contrarily to that observed with MET. DDS-NHOH inhibited catalase (CAT) activity and reactive oxygen species (ROS) generation, but did not alter superoxide dismutase (SOD) activity in erythrocytes. Pretreatment with RSV did not alter these antioxidant enzymes activities in erythrocytes treated with DDS-NHOH. Theoretical calculations using density functional theory methods showed that DDS-NHOH has a pro-oxidant effect, whereas RSV and MET have antioxidant effect on ROS. The effect on methemoglobinemia reversion for MET was significantly higher than that of RSV. These data suggest that the pretreatment with resveratrol may decrease heme-iron oxidation and DNA damage through reduction of ROS generated in cells during DDS therapy.

Clinical follow-up of responses to treatment with benznidazol in Amazon: a cohort study of acute Chagas disease.

A total of 179 individuals with acute Chagas disease mainly transmitted by oral source, from Pará and Amapá State, Amazonian, Brazil were included during the period from 1988 to 2005. Blood samples were used to survey peripheral blood for T. cruzi hemoparasites by quantitative buffy coat (QBC), indirect xenodiagnosis, blood culture and serology to detection of total IgM and anti-T. cruzi IgG antibodies by indirect immunofluorescence assay (IFA) and indirect hemagglutination assay (HA). All assays were performed pre-treatment (0 days) and repeated 35 (±7) and 68 (±6) days after the initiation of treatment with benznidazol and every 6 months while remained seropositive. The endpoint of collection was performed in 2005. Total medium period of follow-up per person was 5.6 years. Also, a blood sample was collected from 72 randomly chosen treated patients to perform polimerase chain reaction (PCR) method. Proportions of subjects with negative or positive serology according to the number of years after treatment were compared. In the endpoint of follow-up we found 47 patients (26.7%) serologically negative, therefore considered cured and 5 (2.7%) exhibited mild cardiac Chagas disease. Other 132 patients had persistent positive serologic tests. The PCR carried out in 72 individuals was positive in 9.8%. Added, there was evidence of therapeutic failure immediately following treatment, as demonstrated by xenodiagnosis and blood culture methods in 2.3% and 3.5% of cases, respectively. There was a strong evidence of antibody clearing in the fourth year after treatment and continuous decrease of antibody titers. Authors suggest that control programs should apply operational researches with new drug interventions four years after the acute phase for those treated patients with persistently positive serology.

Congenital Chagas disease due to acute maternal Trypanosoma cruzi infection transmitted by the oral route / Doença de Chagas congênita por infecção aguda maternal por Trypanosoma cruzi transmitida via oral

A family of four, including a 24-year-old female, presented to our laboratory in December 2006 with a prolonged febrile syndrome of unknown etiology. After extensive laboratory screening, acute Chagas disease was confirmed by positive T. cruzi blood culture, combined with clinical, epidemiological and serological findings. The young female, her parents and husband received a daily dose of benznidazole, but she developed serious drug intolerance and amenorrhea. Her treatment was interrupted by a confirmed pregnancy of about 12 weeks of gestational age. The child was born prematurely on April 18, 2007 with low weight and signs of respiratory distress syndrome. Diagnostic screening tests for congenital infections, including Chagas disease, were negative during the perinatal period. About four months after birth, clinical findings generated the following clinical indicators of congenital disease: convergent strabismus, microcephaly and delayed psychomotor development. Serological tests confirmed seroconversion, and magnetic resonance findings included cystic lesions and intracranial calcifications. The authors discuss the critical nature of this serious public health problem in the region and suggest necessary revisions to the recommended treatment for pregnant patients with acute Chagas disease.

Uma família de quatro pessoas, incluindo uma mulher de 24 anos de idade, apresentou-se em nosso laboratório em dezembro de 2006 com uma síndrome febril prolongada de etiologia desconhecida. Após uma triagem laboratorial extensa, foi confirmada, por meio de hemocultura positiva para T. cruzi, combinada com achados clínicos, epidemiológicos e sorológicos, a ocorrência de doença de Chagas aguda. A paciente, seus pais e marido receberam uma dose diária de benzonidazol, porém ela desenvolveu intolerância severa à droga e amenorreia. Seu tratamento foi interrompido devido à confirmação de gravidez de cerca de 12 semanas de idade gestacional. A criança nasceu prematuramente em 18 de abril de 2007 com baixo peso e sinais de síndrome do desconforto respiratório. Testes de triagem diagnóstica para infecções congênitas, incluindo a doença de Chagas, resultaram negativos durante o período perinatal. Aproximadamente quatro meses após o nascimento, os achados clínicos forneceram os seguintes indicadores clínicos de doença congênita: esotropia, microcefalia e atraso no desenvolvimento psicomotor. Testes sorológicos confirmaram a soroconversão e a ressonância magnética apresentou lesões císticas e calcificações intracranianas. Os autores discutem a natureza crítica deste grave problema de saúde pública na região e sugerem revisões necessárias ao tratamento recomendado para pacientes grávidas com a doença de Chagas aguda.

Alterações eletrocardiográficas durante e após tratamento com benzonidazol em fase aguda de doença de Chagas autóctone da Amazônia brasileira / Electrocardiographic changes during and after benznidazole treatment against acute-stage Chagas disease indigenous to the Brazilian Amazon

Avaliar o comprometimento cardíaco associado às infecções agudas por Tripanosomas considerando os distúrbios de condução elétrica e ritmo cardíacos apresentados durante a fase aguda e após tratamento, em uma casuística de doença de Chagas autóctone da Amazônia. Foram analisadas duas coortes de indivíduos: uma em fase aguda (coorte I) e outra (coorte II) feita nos mesmos pacientes reavaliados em período médio da primeira coorte, de 3,9 anos após tratamento. Entre os indivíduos da coorte I, a análise eletrocardiográfica foi realizada em eletrocardiogramas recuperados e submetidos à nova leitura e em eletrocardiogramas realizados prospectivamente. Todos foram submetidos a tratamentos regulares com benzonidazol. Foram estudados 179 indivíduos que tiveram doença de Chagas aguda no período entre 1992 e 2005. Na fase aguda, 47,7 por cento dos traçados eletrocardiográficos apresentaram-se normais e em 52,3 por cento registraram-se anormalidades. As alterações difusas de repolarização ventricular e baixa voltagem de QRS foram as principais anormalidades. Em 39,1 por cento dos pacientes houve comprometimento cardíaco caracterizado por miopericardite, sendo que 24,3 por cento (17/70) dos casos foram considerados graves. Foi demonstrada maior frequência de alterações eletrocardiográficas após tratamento em pacientes que manifestaram alteração eletrocardiográfica durante a fase aguda, comparativamente àqueles que não apresentaram. Outros cinco indivíduos que apresentaram diagnósticos tardios e manifestaram miocardite difusa durante o período agudo evoluíram insatisfatoriamente, uma vez que desenvolveram forma cardíaca com lesões de cardiopatia crônica...

This article aims to assess the cardiac impairment associated with acute infections by Trypanosoma considering abnormalities in electrical conduction and heart rate during the acute phase and after treatment in a case-study of Chagas' disease indigenous to the Amazon. The individuals assessed were grouped into two cohorts: cohort I had patients during the acute phase of the disease; and cohort II included the same patients re-evaluated at the average period of the first cohort, 3.9 years after treatment. The electrocardiographic analysis of the individuals in cohort I was based both on restored electrocardiograms that underwent a new reading and on electrocardiograms performed prospectively. All patients were treated with benznidazole on a regular basis. A total of 179 individuals that had acute Chagas disease in the period between 1992 and 2005 were assessed. During the acute phase, 47.7 per cent of the electrocardiographic tracings were normal, and 52.3 per cent reported abnormalities. The diffuse changes in ventricular repolarization and low QRS voltage were the main abnormalities reported. Cardiac impairment characterized by myopericarditis was observed in 39.1 per cent of the patients, and 24.3 per cent (17/70) of the cases were considered severe. The electrocardiographic changes were more frequent after treatment of patients who had shown electrocardiographic abnormalities during the acute phase, when compared to those who had not. Five other individuals who were diagnosed late and presented with diffuse myocarditis during the acute phase evolved poorly because they developed a clinical picture with lesions of chronic cardiopathy...

Investigation of two outbreaks of suspected oral transmission of acute Chagas disease in the Amazon region, Para State, Brazil, in 2007.

Acute Chagas disease (ACD) is caused by Trypanosoma cruzi. ACD outbreaks due to probable oral transmission occur regularly in small family gatherings that are exposed to contaminated foods. We studied two cohorts of residents on islands in the Breves and Bagre municipalities, in July and August 2007, to identify risk factors of transmission and to recommend preventative measures. Of the 25 cases identified in both cohorts, 13 (52%) were men, and the most frequent symptoms were fever (96%),asthenia (80%), myalgia (76%), abdominal pain (64%), retro-orbital pain, headaches and asthma (52%). We recommend detailed investigation of future outbreaks and other studies to better understand and control oral transmission of T. cruzi.

Urban outbreak of acute Chagas disease in Amazon region of Brazil: four-year follow-up after treatment with benznidazole.

The objective of this report is to describe treatment outcomes over a four-year period of patients with acute Chagas disease in the Amazon region of Brazil. An outbreak of Chagas disease in a low-income district of urban Belém, in September 2000, affected 11 people simultaneously, indicating the likelihood of indirect, oral transmission of Trypanosoma cruzi. Prior to treatment, patients underwent physical and clinical tests; blood samples were processed with immunofluorescence assay (IFA) and quantitative buffy coat (QBC). Following treatment with benznidazole, parasitological and serologic tests (artificial xenodiagnosis and blood culture for T. cruzi), electrocardiogram, and echocardiogram were administered at intervals over a four-year period. Four years after treatment for acute Chagas disease, all patients presented with negative parasitological tests and persistent IgG anti-T. cruzi antibodies with lowered titers; three patients presented electrocardiogram abnormalities consistent with chronic Chagas disease or sequel of acute disease. The satisfactory response to treatment and relevance of serial parasitological examinations of patients with acute Chagas disease are discussed.

Analysis of an acute Chagas disease outbreak in the Brazilian Amazon: human cases, triatomines, reservoir mammals and parasites.

An outbreak of Chagas disease occurred in Mazagão, Amapá, Brazilian Amazon in 1996. Seventeen of 26 inhabitants presented symptoms compatible with acute Chagas disease and were submitted to parasitological and serological tests. All 17 were positive in at least one parasitological test and 11 were also IgM or IgG anti-Trypanosoma cruzi positive. The nine asymptomatic patients were negative for parasites and one was positive for IgG anti-T. cruzi. Sixty-eight triatomines were captured (66 Rhodnius pictipes; two Panstrongylus geniculatus); 45 were infected with T. cruzi (43 R. pictipes; two P. geniculatus). Thirteen trypanosomatid strains were isolated: eight from humans and five from R. pictipes. Four were genotyped as T. cruzi I (two from humans; two from R. pictipes), seven as T. cruzi Z3 (six from humans; one from R. pictipes) and two as T. cruzi Z3 and T. rangeli (from R. pictipes). Treatment started for all patients leading to a decrease in parasitaemia in 16 during the follow-up period (6 months, 1, 5 and 7 years). All were serologically negative 7 years post-treatment. There was an overlap of genotypes in the same ecotope, raising the possibility of transmission through the oral route and the need for early therapeutic intervention for better patient management in the Brazilian Amazon.

Urban outbreak of acute Chagas disease in Amazon region of Brazil: four-year follow-up after treatment with benznidazole / Brote urbano de enfermedad aguda de Chagas en la región amazónica de Brasil: seguimiento de cuatro años después del tratamiento con benznidazol

The objective of this report is to describe treatment outcomes over a four-year period of patients with acute Chagas disease in the Amazon region of Brazil. An outbreak of Chagas disease in a low-income district of urban Belém, in September 2000, affected 11 people simultaneously, indicating the likelihood of indirect, oral transmission of Trypanosoma cruzi. Prior to treatment, patients underwent physical and clinical tests; blood samples were processed with immunofluorescence assay (IFA) and quantitative buffy coat (QBC). Following treatment with benznidazole, parasitological and serologic tests (artificial xenodiagnosis and blood culture for T. cruzi), electrocardiogram, and echocardiogram were administered at intervals over a four-year period. Four years after treatment for acute Chagas disease, all patients presented with negative parasitological tests and persistent IgG anti-T. cruzi antibodies with lowered titers; three patients presented electrocardiogram abnormalities consistent with chronic Chagas disease or sequel of acute disease. The satisfactory response to treatment and relevance of serial parasitological examinations of patients with acute Chagas disease are discussed.

El objetivo de este informe es describir los resultados del tratamiento para la enfermedad aguda de Chagas durante un seguimiento de cuatro años en pacientes de la región amazónica de Brasil. Un brote de la enfermedad de Chagas en un distrito de bajos ingresos de la parte urbana de Belém afectó simultáneamente a 11 personas en septiembre de 2000; al parecer, la transmisión de Trypanosoma cruzi fue indirecta por vía oral. Antes del tratamiento, los pacientes se sometieron a un examen físico y pruebas clínicas; las muestras de sangre se estudiaron mediante inmunofluorescencia - indirecta y análisis cuantitativo de la capa leucocitaria (buffy coat). Después del - tratamiento con benznidazol se realizaron pruebas parasitológicas y serológicas (xenodiagnóstico artificial y hemocultivo de T. cruzi), electrocardiogramas y ecocardiogramas periódicos durante cuatro años. Cuatro años después del tratamiento por enfermedad aguda de Chagas, todos los pacientes eran negativos en los análisis parasitológicos y disminuyeron los títulos de anticuerpos IgM anti-T. cruzi persistentes; tres pacientes presentaron alteraciones electrocardiográficas indicadoras de enfermedad crónica de Chagas o de secuelas de la enfermedad aguda. Se discute la respuesta satisfactoria al tratamiento y la importancia de los análisis parasitológicos seriados de los pacientes con enfermedad aguda de Chagas.

Fase aguda da doença de Chagas na Amazônia brasileira: estudo de 233 casos do Pará, Amapá e Maranhão observados entre 1988 e 2005 / Acute phase of Chagas disease in the Brazilian Amazon region: study of 233 cases from Pará, Amapá and Maranhão observed between 1988 and 2005

Foram estudados 233 casos de fase aguda da doença de Chagas, oriundos do Pará, Amapá e Maranhão, observados no período de 1988 a 2005, cento e sessenta deles retrospectivamente de 1988 a 2002 e setenta e três prospectivamente de 2003 a 2005. Entre os casos estudados 78,5 por cento (183/233) faziam parte de surtos provavelmente por transmissão oral, acometendo em média 4 pessoas e 21,5 por cento (50/233) eram casos isolados. Foram considerados casos agudos aqueles que apresentaram exames parasitológicos diretos (a fresco, gota espessa ou Quantitative Buffy Coat - QBC) e/ou IgM anti-Trypanosoma cruzi positivos. Foram feitos ainda xenodiagnósticos em 224 pacientes e hemoculturas em 213. Todos foram avaliados clinica e epidemiologicamente. As manifestações clínicas mais freqüentes foram febre (100 por cento), cefaléia (92,3 por cento), mialgia (84,1 por cento), palidez (67 por cento), dispnéia (58,4 por cento), edema de membros inferiores (57,9 por cento), edema de face (57,5 por cento) dor abdominal (44,2 por cento), miocardite (39,9 por cento) e exantema (27 por cento). O eletrocardiograma mostrou alterações de repolarização ventricular em 38,5 por cento dos casos, baixa voltagem de QRS em 15,4 por cento e desvio de SAQRS em 11,5 por cento, extra-sístoles ventriculares em 5,8 por cento, bradicardia em 5,8 por cento e taquicardia em 5,8 por cento, bloqueio de ramo direito em 4,8 por cento e fibrilação atrial em 4,8 por cento. A alteração mais freqüente vista no ecocardiograma foi o derrame pericárdico em 46,2 por cento dos casos. Treze (5,6 por cento) pacientes evoluíram para o óbito, 10 (76,9 por cento) dos quais por comprometimento cardiovascular, dois por complicações de origem digestiva e um de causa mal definida.

Two hundred and thirty-three cases of the acute phase of Chagas disease, from Pará, Amapá and Maranhão, were observed between 1988 and 2005. One hundred and sixty were studied retrospectively from 1988 to 2002 and seventy-three were prospectively followed up from 2003 to 2005. Among the cases studied, 78.5 percent (183/233) formed part of outbreaks, probably due to oral transmission (affecting a mean of 4 individuals), and 21.5 percent (50/233) were isolated cases. Cases were taken to be acute if they presented positive direct parasitological tests (fresh blood, thick drop or Quantitative Buffy Coat, QBC) and/or positive anti Trypanosoma cruzi IgM. Xenodiagnosis was also performed on 224 patients and blood culturing on 213. All the patients had clinical and epidemiological evaluations. The most frequent clinical manifestations were fever (100 percent), headache (92.3 percent), myalgia (84.1 percent), pallor (67 percent), dyspnea (58.4 percent), swelling of the legs (57.9 percent), facial edema (57.5 percent), abdominal pain (44.3 percent), myocarditis (39.9 percent) and exanthema (27 percent). The electrocardiogram showed abnormalities of ventricular repolarization in 38.5 percent, low QRS voltage in 15.4 percent, left-axis deviation in 11.5 percent, ventricular ectopic beats in 5.8 percent, bradycardia in 5.8 percent, tachycardia in 5.8 percent, right branch block in 4.8 percent and atrial fibrillation in 4.8 percent. The most frequently observed abnormality on the echocardiogram was pericardial effusion, in 46.2 percent of the cases. Thirteen (5.6 percent) patients died: ten (76.9 percent) of them due to cardiovascular involvement, two due to digestive complications and one due to indeterminate causes.

[Acute phase of Chagas disease in the Brazilian Amazon region: study of 233 cases from Pará, Amapá and Maranhão observed between 1988 and 2005]. / Fase aguda da doença de Chagas na Amazônia brasileira: estudo de 233 casos do Pará, Amapá e Maranhão observados entre 1988 e 2005.

Two hundred and thirty-three cases of the acute phase of Chagas disease, from Pará, Amapá and Maranhão, were observed between 1988 and 2005. One hundred and sixty were studied retrospectively from 1988 to 2002 and seventy-three were prospectively followed up from 2003 to 2005. Among the cases studied, 78.5% (183/233) formed part of outbreaks, probably due to oral transmission (affecting a mean of 4 individuals), and 21.5% (50/233) were isolated cases. Cases were taken to be acute if they presented positive direct parasitological tests (fresh blood, thick drop or Quantitative Buffy Coat, QBC) and/or positive anti Trypanosoma cruzi IgM. Xenodiagnosis was also performed on 224 patients and blood culturing on 213. All the patients had clinical and epidemiological evaluations. The most frequent clinical manifestations were fever (100%), headache (92.3%), myalgia (84.1%), pallor (67%), dyspnea (58.4%), swelling of the legs (57.9%), facial edema (57.5%), abdominal pain (44.3%), myocarditis (39.9%) and exanthema (27%). The electrocardiogram showed abnormalities of ventricular repolarization in 38.5%, low QRS voltage in 15.4%, left-axis deviation in 11.5%, ventricular ectopic beats in 5.8%, bradycardia in 5.8%, tachycardia in 5.8%, right branch block in 4.8% and atrial fibrillation in 4.8%. The most frequently observed abnormality on the echocardiogram was pericardial effusion, in 46.2% of the cases. Thirteen (5.6%) patients died: ten (76.9%) of them due to cardiovascular involvement, two due to digestive complications and one due to indeterminate causes.

Estudos dos surtos de doença de Chagas ocorridas no Pará e Amapá: análise parasitológica, sorológica e molecular / Studies of the occured surtos of illness of Chagas in Pará and Amapá: parasitologic, sorologic and molecular analysis

Relatos de casos de Doença de Chagas na Amazônia Brasileira têm sido relativamente freqüentes na literatura. Entretanto, não se encontram relatos desses surtos acompanhados sistematicamente. Durante os últimos anos, o Instituto Evandro Chagas teve a oportunidade de fazer o seguimento de vários surtos agudos da doença, e nessa tese são descritas análises parasitológicas, sorológicas, entomológicas e de reservatórios de seis deles, utilizando desde técnicas tradicionais, até técnicas moleculares. A pesquisa parasitológica foi realizada em 423 pessoas (sintomáticos e contatos) relacionadas aos surtos do Pará (Abaetuba, Ananindeua, Barcarena, Belém e Bragança) e do Amapá (Mazagão). Foram encontradas 28,6 por cento (121/423) de positividade em pelo menos um dos testes parasitológicos: 44,62 por cento (54/121) na gota espessa; 9,09 por cento (11/121) no QBC®; 81 por cento (98/121) no xenodiagnósticos e 60 por cento (73/121) na hemocultura. A pesquisa sorológica incluiu uma amostragem de 3633 pessoas nos municípios estudados. No teste de triagem (HAI) foram detectados 4,40 por cento dos indivíduos positivos (160/3633). Pelo teste de IFI para pesquisa de IgG estes soros apresentaram positividade de 3,19 por cento (116/3633) e 3,02 por cento(110/3633) apresentaram testes positivos para anticorpos IgM anti-Trypanosoma cruzi. Os pacientes diagnosticados (n=121) foram tratados e acompanhados pelo menos até dois anos. Realizou-se o seguimento dos exames laboratoriais em 4 cortes de tempo: antes de tratar, 6 meses, 1 ano e 2 anos após tratamento, exceto o surto de Mazagão que teve os seguimentos expandidos para cinco e sete anos. Os exames parasitológicos negativaram em 118 (97,52 por cento) pacientes. Três pacientes foram re-tratados e negativaram os testes parasitológicos subseqüentes. Em 5 surtos os exames sorológicos seguidos até dois anos revelaram negativação da IgM e redução progressiva dos títulos de IgG sem desaparecimento da imunoglobulina

No surto de Mazagão, todos os pacientes se revelaram sorologicamente negativos após 7 anos. Dos 145 mamíferos silvestres capturados, 75 foram Didelphis marsupialis, 34 Philander opossum, 21 marmosa cinera, 2 marmosa murina e 13 Proechimys guyanensis. Destes 56 foram coletados em Abaetetuba, 7 em Ananindeua, 40 em Barcarena, 5 em Belém, 25 em Bragança e 12 em Mazagão. A taxa de infecção por Trypanosoma cruzi foi de 68,96. No surto de Mazagão, todos os pacientes se revelaram sorologicamente negativos após 7 anos. Dos 145 mamíferos silvestres capturados, 75 foram Didelphis marsupialis, 34 Philander opossum, 21 Marmosa cinera, 2 Marmosa murina e 13 Proechimys guyanensis. Destes 56 foram coletados em Abaetetuba, 7 em Ananindeua, 40 em Barcarena, 5 em Belém, 25 em Bragança e 12 em Mazagão. A taxa de infecção por Trypanosoma cruzi foi de 68,96 por cento (100/145), sendo 69,33 por cento dos D. marsupialis (52/75), 70,58 por cento dos P. opossum (24/34), 61,90 por cento das M. cinerea (13/21), 100 por cento das M. murina (2/2) e 69,23 por cento dos P. guyanensis (9/13). Foram capturados 1022 triatomíneos de 5 espécies.

As taxas de infecção foram R. pictipes - 51,81 por cento; R. robustus - 14 por cento; Rhodnius milesi - 33 por cento; Panstrongylus geniculatus - 51,47 por cento e Panstrongylus lignarius - 27,27 por cento). Os sítios de coleta foram palmeiras (73,09 por cento); armadilhas de luz (17,31 por cento) e sitios diversos (9,6). Um dos surtos teve o importante agrupamento dos casos de forma familiar levando a hipótese de transmissão pela mesma via e infecção, possivelmente a via oral sendo o suco de açaí o único alimento encontrado associdado a este grupo. A tipagem de mini-exon mostrou a existência de TC 1 e TC Z3. Trypanosoma rangeli também foi evidenciado na região. A tipagem de RAPD gerou uma diversidade tão grande que não foi possível chegar a qualquer conclusão, exceto a diversidade existente entre os parasitos que circulam nos surtos e a possível multiclonalidade dos isolados.

Doença de Chagas aguda grave autóctone da Amazônia Brasileira / Serious acute Chagas Disease authoctonous from Brazilian Amazon

Objetivo: analisar o quadro clinico-laboratorial de casos de Doença de Chagas aguda autóctone da Amazônia brasileira avaliados sob regime hospitalar, enfatizando a síndrome febril e sinais potenciais de comprometimento cardíaco futuro. Método: estudo transversal de casos de Doença de Chagas aguda, internados no Hospital Universitário João de Barros Barreto, de janeiro de 1990 a outubro de 2003. Resultados: em 20 casos estudados encontramos febre em 95% deles, sendo metade do tipo recorrente, dispnéia (75%), astenia (65%), edema de membros inferiores (65%) e cefaléia (60%). As principais alterações eletrocardiográficas foram: taquicardia sinusal, alterações difusas da repolarização ventricular e complexo QRS de baixa voltagem. Observou-se derrame pericárdico em 35% dos ecocardiogramas realizados. Conclusõe. a elevada freqüência da síndrome febril na doença de Chagas aguda expressa a importância do correto diagnóstico diferencial com as demais endemiasfebris da Amazônia. As alterações eletrocardiográficas e ecocardiográficas encontradas podem sugerir forma clínica de transição para cronicidade, além de indicar gravidade.

Objective: To analyze clinical and laboratorial findings of authoctononus acute Chagas disease from Brazilian Amazon, evaluated under hospital regimen, emphasizing feverish syndrome observations and potential signs of future cardiac commitment. Method: Transversal study of acute Chagas disease in patients from University Hospital João de Barros Barreto, within jan 1990 to at 2003. Results: In a total of 20 studied cases we found predominant symptoms: fever (95%), dyspnea (75%), asthenia (65%), edema of lower members (65%) and headache (60%). Main abnonnalities found in electrocardiograms were: sinusal tachycardia, diffuse ventricular repolarization abnormalities and low voltage of QRS. We demonstrated 35% with pericardial effusion show in echocardiograms. Conclusions: Raised frequency of feverish syndrome in acute Chagas disease shows the importance of the correct distinguishing diagnosis with others febrile endemic diseases occurred in Amazon. The electrocardiographics and echocardiographics abnormalíties found could suggest clínical form of transition for chronicity, besides expressing gravity.

Resolution of multiclonal infections of Trypanosoma cruzi from naturally infected triatomine bugs and from experimentally infected mice by direct plating on a sensitive solid medium.

The isolation of biological clones of Trypanosoma cruzi by microscopically dispensing individual organisms or by serial dilution is laborious and time consuming. The inability to resolve mixed T. cruzi infections, from vectors and hosts, and to isolate clones of slow growing genotypes by efficient plating on solid media, has hindered characterisation studies and downstream applications. We have devised and validated a sensitive, solid medium plating technique for rapid in vitro isolation of clones representative of all the recognised T. cruzi lineages (TCI, TCIIa-e), including the slow growing strain CANIII (TC IIa) and Trypanosoma rangeli, with high plating efficiencies. Furthermore, the method is effective for the isolation of clones directly from silvatic triatomine bugs and from experimentally infected mice harbouring mixed infections, allowing resolution of multiclonal infections from varied sources.