Santana Rosa Amélia Gonçalves, Magalhães Laylah Kelre Costa, Magalhães Laise Kelman Costa, Prestes Suzane Ribeiro, Maciel Marcel Gonçalves, da Silva George Allan Villarouco, Monteiro Wuelton Marcelo, de Brito Felipe Rocha, de Aguiar Raposo Câmara Coelho Leila Inês, Barbosa-Ferreira João Marcos, Guerra Jorge Augusto Oliveira, Silveira Henrique, das Graças Vale Barbosa Maria
Institute of Hygiene and Tropical Medicine (Instituto de Higiene e Medicina Tropical), New University of Lisbon (Universidade Nova de Lisboa), Lisbon, Portugal.
Parasit Vectors. 2014 Jun 11;7:267. doi: 10.1186/1756-3305-7-267.
Chagas disease in the Amazon region is considered an emerging anthropozoonosis with a predominance of the discrete typing units (DTUs) TcI and TcIV. These DTUs are responsible for cases of acute disease associated with oral transmission. Chronic disease cases have been detected through serological surveys. However, the mode of transmission could not be determined, or any association of chronic disease with a specific T. cruzi DTU's. The aim of this study was to characterize Trypanosoma cruzi in patients with chronic Chagas disease in the State of Amazonas, Brazil.
Blood culture and xenodiagnosis were performed in 36 patients with positive serology for Chagas disease who participated in a serological survey performed in urban and rural areas of Manaus, Amazonas. DNA samples were extracted from the feces of triatomines used for xenodiagnosis, and the nontranscribed spacer of the mini-exon gene and the mitochondrial gene cytochrome oxidase subunit II (COII) were amplified by PCR and sequenced.
Blood culture and xenodiagnosis were negative in 100% of samples; however, molecular techniques revealed that in 13 out of 36 (36%) fecal samples from xenodiagnosis, T. cruzi was characterized as the DTU TcI, and different haplotypes were identified within the same DTU.
The DTU TcI, which is mainly associated with acute cases of Chagas disease in the Amazon region, is also responsible for chronic infection in patients from a region in the State of Amazonas.
亚马逊地区的恰加斯病被认为是一种新兴的人兽共患病，主要的离散型分型单元（DTUs）为TcI和TcIV。这些DTUs导致了与经口传播相关的急性病例。通过血清学调查已检测到慢性病例。然而，传播方式无法确定，也无法确定慢性疾病与特定克氏锥虫DTU之间的任何关联。本研究的目的是对巴西亚马孙州慢性恰加斯病患者的克氏锥虫进行特征分析。
对36例恰加斯病血清学检测呈阳性的患者进行了血培养和虫媒接种诊断，这些患者参与了在亚马孙州玛瑙斯城乡进行的血清学调查。从用于虫媒接种诊断的锥蝽粪便中提取DNA样本，通过PCR扩增微型外显子基因的非转录间隔区和线粒体基因细胞色素氧化酶亚基II（COII）并进行测序。
100%的样本血培养和虫媒接种诊断均为阴性；然而，分子技术显示，在36份虫媒接种诊断的粪便样本中，有13份（36%）的克氏锥虫被鉴定为DTU TcI，并且在同一DTU内鉴定出了不同的单倍型。
主要与亚马逊地区恰加斯病急性病例相关的DTU TcI，也是亚马孙州某地区患者慢性感染的病因。
