Cardiopatia chagásica crônica no Rio Negro, Estado do Amazonas. Relato de três novos casos autóctones, comprovados por exames sorológicos, clínicos, radiográficos do tórax, eletro e ecocardiográficos

Abstract

We report three new autochthonous cases of chronic chagasic cardiomyopathy from Rio Negro, Amazon State, confirmed by serology (indirect immunofluorescence, ELISA and Western-blot for Trypanosoma cruzi infection), clinical examination, chest X-rays, electro- and echocardiography. The three patients were born and lived all their lives in the Rio Negro region working as piaçaba gatherers, where they were bitten several times by sylvatic triatomine bugs. The clinical feature was congestive heart failure and intraventricular conduction impairment in the three cases (right bundle branch block with left anterior hemiblock in two cases, left bundle branch block of 3rd degree in one), polymorphic ventricular extrasystoles in two cases and primary T wave inversion in another one. The echocardiographic evaluation showed a significant increasing of the left ventricular diameters with ejection fraction lesser than 36%, and myocardial segmental impairment pattern, including apical aneurysm and postero-inferior akinesia in the three patients. These are the first autochthonous cases of chronic Chagasic cardiomyopathy from the Brazilian Amazon state with echocardiographic pattern suggestive of Chagas' disease.

A new survey of the serology of human Trypanosoma cruziinfection in the Rio Negro microregion, Brazilian Amazon: a critical analysis

“…The numbers of blood samples collected on filter paper, along with the percentage of positivity for T. cruzi infection, varied according to the number of people living in the area and their degree of exposure to infection in rural areas, especially in relation to piassava harvesters and their families. This characteristic has already been presented in previous studies by our group ( Coura et al 1995a , b , 2002a , b , 1999 , Albajar et al 2003 a, b, Junqueira et al 2005 , Xavier et al 2006 , Brum-Soares et al 2010 , Coura & Junqueira 2012 , Junqueira et al 2013 ).…”

“…As a result of this previous study and due to our greater experience with Chagas disease in the area ( Coura et al 2002b , Albajar et al 2003 , Junqueira et al 2005 , Xavier et al 2006 , Brum-Soares et al 2010 ), we decided in 2010 to conduct a new and larger serological survey in this area to correct certain technical interpretations regarding the previous serological surveys, including those related to immunofluorescence. For unknown reasons, intense immunofluorescence is frequently observed on the parasite's body in this region or at some points of its membrane, sometimes interpreted erroneously as positive when this staining is actually a false-positive.…”

Epidemiology, control and surveillance of Chagas disease: 100 years after its discovery

“…Serological surveys and cross-sectional studies carried out by Fundação Nacional de Saúde from 1975-1980, in different states in the Brazilian Amazon Region, and by Coura et al from 1971Coura et al from -2002 in AM showed prevalences ranging from 2.4-13.2% (Camargo et al 1984, Coura et al 1999. Severe chronic cases of Chagas disease have also been reported in the Brazilian Amazon Region (Albajar et al 2003, Junqueira et al 2005, Xavier et al 2006). …”

Chagas disease: What is known and what should be improved: a systemic review

“…Taking into considering the small number of patients, it was not possible to safely evaluate the real morbidity of Chagas disease. However, typical and fatal cases of chronic Chagas heart disease have been described in this area 94,95 .…”

“…Over the last 20 years (1991-2011), we have developed seroepidemiological surveys and clinical, radiological and electrocardiographic studies among populations that were seropositive for Chagas infection, in the middle and upper regions of the Negro River, in the State of Amazonas [72][73][74][76][77][78] . Several typical and fatal chronic cases of Chagas disease were described 94,95 , involving more than 7,000 screening serological reactions and more than 300 confirmatory serological reactions. In three preliminary seroepidemiological surveys conducted in 1991, 1993 and 1997, we carried out 2,254 screening serological reactions using IIF on blood collected on filter paper and found that the mean positivity rate was 13% 76 , although only 2.5% to 5% were confirmed by means of serum IIF, ELISA and trypomastigote excreted-secreted antigens (TESA)-blot.…”