Trypanosoma cruzi discrete typing unit TcIV implicated in a case of acute Chagas disease in a domiciliated dog in the western Amazon

Abstract Chagas disease is caused by the protozoan Trypanosoma cruzi. Seven lineages have been identified based on different molecular markers, namely TcI, TcII, TcIII, TcIV, TcV, TcVI, and TcBat. Dogs play the role of epidemiological sentinels being domestic reservoirs of T. cruzi. The aim of the current study was to report the first case of CD in a domestic dog in Manaus, Amazonas, Brazil, infected with T. cruzi DTU TcIV. We hope our report encourages veterinarians and surveillance professionals to a take a deeper look at T. cruzi infection in domestic animals.

Implantable cardioverter-defibrillator prevents sudden death in patients with Chagas cardiomyopathy in the Brazilian Amazon

Abstract Chagas disease (CD), with approximately 10,000 deaths annually, has become a worldwide health problem. Approximately 35% of cases may show cardiac manifestations such as arrhythmias and/or conduction disorders, heart failure, thromboembolic accidents, and sudden death. The Amazon region has long been considered a non-endemic area for CD; however, in the last decades, with an increase in the number of acute and chronic cases, disease evolution has received greater attention. Here, we report the successful implementation of a cardioverter-defibrillator for the prevention of sudden death in a patient with autochthonous Chagas cardiomyopathy in the Brazilian Amazon.

Polymerase chain reaction-based method for the identification of Leishmania (Viannia) braziliensis and Leishmania (Viannia) guyanensis in mucosal tissues conserved in paraffin

ABSTRACTINTRODUCTION: In the Americas, mucosal leishmaniasis is primarily associated with infection by Leishmania (Viannia) braziliensis. However, Leishmania (Viannia) guyanensis is another important cause of this disease in the Brazilian Amazon. In this study, we aimed at detecting Leishmaniadeoxyribonucleic acid (DNA) within paraffin-embedded fragments of mucosal tissues, and characterizing the infecting parasite species.METHODS: We evaluated samples collected from 114 patients treated at a reference center in the Brazilian Amazon by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses.RESULTS: Direct examination of biopsy imprints detected parasites in 10 of the 114 samples, while evaluation of hematoxylin and eosin-stained slides detected amastigotes in an additional 17 samples. Meanwhile, 31/114 samples (27.2%) were positive for Leishmania spp. kinetoplast deoxyribonucleic acid (kDNA) by PCR analysis. Of these, 17 (54.8%) yielded amplification of the mini-exon PCR target, thereby allowing for PCR-RFLP-based identification. Six of the samples were identified as L. (V.) braziliensis, while the remaining 11 were identified as L. (V.) guyanensis.CONCLUSIONS: The results of this study demonstrate the feasibility of applying molecular techniques for the diagnosis of human parasites within paraffin-embedded tissues. Moreover, our findings confirm that L. (V.) guyanensisis a relevant causative agent of mucosal leishmaniasis in the Brazilian Amazon.

Chagas disease in the State of Amazonas: history, epidemiological evolution, risks of endemicity and future perspectives

Chagas disease (CD) is a parasitic infection that originated in the Americas and is caused by Trypanosoma cruzi. In the last few years, the disease has spread to countries in North America, Asia and Europe due to the migration of Latin Americans. In the Brazilian Amazon, CD has an endemic transmission, especially in the Rio Negro region, where an occupational hazard was described for piaçaveiros (piassaba gatherers). In the State of Amazonas, the first chagasic infection was reported in 1977, and the first acute CD case was recorded in 1980. After initiatives to integrate acute CD diagnostics with the malaria laboratories network, reports of acute CD cases have increased. Most of these cases are associated with oral transmission by the consumption of contaminated food. Chronic cases have also been diagnosed, mostly in the indeterminate form. These cases were detected by serological surveys in cardiologic outpatient clinics and during blood donor screening. Considering that the control mechanisms adopted in Brazil's classic transmission areas are not fully applicable in the Amazon, it is important to understand the disease behavior in this region, both in the acute and chronic cases. Therefore, the pursuit of control measures for the Amazon region should be a priority given that CD represents a challenge to preserving the way of life of the Amazon's inhabitants.

Biological behavior of Trypanosoma cruzi stocks obtained from the state of Amazonas, Western Brazilian Amazon, in mice / Comportamento biológico de isolados de Trypanosoma cruzi obtidos no estado do Amazonas, Amazônia Ocidental Brasileira, em camundongos

INTRODUCTION: The biological diversity of circulating Trypanosoma cruzi stocks in the Amazon region most likely plays an important role in the peculiar clinic-epidemiological features of Chagas disease in this area. METHODS: Seven stocks of T. cruzi were recently isolated in the State of Amazonas, Brazil, from humans, wild mammals, and triatomines. They belonged to the TcI and Z3 genotypes and were biologically characterized in Swiss mice. Parasitological and histopathological parameters were determined. RESULTS: Four stocks did not promote patent parasitemia in mice. Three stocks produced low parasitemia, long pre-patent periods, and a patent period of 1 day or oscillating parasitemia. Maximum parasitemia ranged from 1,400 to 2,800 trypomastigotes/0.1mL blood. Mice inoculated with the T. cruzi stocks studied showed low positivity during fresh blood examinations, ranging from 0% to 28.6%. In hemoculture, positivity ranged from 0% to 100%. Heart tissue parasitism was observed in mice inoculated with stocks AM49 and AM61. Stock AM49 triggered a moderate inflammatory process in heart tissue. A mild inflammatory process was observed in heart tissue for stocks AM28, AM38, AM61, and AM69. An inflammatory process was frequently observed in skeletal muscle. Examinations of brain tissue revealed inflammatory foci and gliosis in mice inoculated with stock AM49. CONCLUSIONS: Biological and histopathological characterization allowed us to demonstrate the low infectivity and virulence of T. cruzi stocks isolated from the State of Amazonas.

INTRODUÇÃO: A diversidade biológica dos estoques Trypanosoma cruzi circulantes na Região Amazônica pode desempenhar importante papel nas características clínico-epidemiológicas peculiares da doença de Chagas nesta área. MÉTODOS: Sete isolados de T. cruzi do Estado do Amazonas provenientes de humanos, mamíferos silvestres e triatomíneos, pertencentes aos genótipos TcI e Z3, foram biologicamente caracterizados em camundongos Swiss. Foram avaliados parâmetros parasitológicos e histopatológicos. RESULTADOS: Quatro isolados não produziram parasitemia patente em camundongos. Três isolados promoveram baixa parasitemia com longos períodos pré-patentes, período patente de um dia ou parasitemia oscilante. A parasitemia máxima variou de 1.400 a 2.800 tripomastigotas/0,1mL de sangue. Os camundongos inoculados com os isolados estudados mostraram baixa positividade no exame a fresco, variando de 0 a 28,6%. Para a hemocultura, a positividade variou de 0 a 100%. Parasitismo cardíaco foi observado em camundongos inoculados com os isolados AM49 e AM61. O isolado AM49 produziu inflamação moderada no tecido cardíaco. Processo inflamatório discreto foi observado no tecido cardíaco de camundongos inoculados com os isolados AM28, AM38, AM61 e AM69. Processo inflamatório em músculo esquelético foi muito frequente. O exame do tecido cerebral revelou focos inflamatórios e gliose em camundongos inoculados com o isolado AM49. CONCLUSÕES: A caracterização biológica e histopatológica demonstrou baixa infecciosidade e virulência dos estoques de T. cruzi isolados no Estado do Amazonas.