Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (ICIVET Litoral), Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas (UNL-CONICET), Argentina.
Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (ICIVET Litoral), Universidad Nacional del Litoral - Consejo Nacional de Investigaciones Científicas y Técnicas (UNL-CONICET), Argentina.
Vet Parasitol. 2014 May 28;202(3-4):226-33. doi: 10.1016/j.vetpar.2014.02.043. Epub 2014 Feb 26.
Trypanosoma evansi is a flagellated protozoan that parasitizes a wide variety of mammals, occasionally including humans. In South America, it infects horses, cattle, buffaloes, dogs and wild mammals, causing a disease known as "Mal de Caderas", which results in important economic losses due to a wide range of pathological expressions. Argentina represents the southern limit of its distribution. The capybara (Hydrochoerus hydrochaeris) is a large rodent found in tropical to temperate freshwater wetlands of South America. As capybaras infected with T. evansi present no clinical signs of disease, withstanding high parasitaemia, this species was proposed as a reservoir host. In this study we investigated the prevalence and parasitaemic intensity of T. evansi in samples obtained from 60 free-ranging capybaras of Esteros del Iberá (Corrientes province, northeastern Argentina) using smear microscopy and real-time PCR assays. All the cases of capybaras infected with T. evansi were found during one of the years studied, with no evidence of seasonality. The overall infection prevalence was 10%, but between years it ranged from 0% to 17% (in 2011). This is the first confirmation of T. evansi infection in Argentina by molecular biology techniques. Our results showed no differences between the methods used to detect the presence of T. evansi in capybaras, which indicates that simple methods like microscopy can generate important data on the ecoepidemiology of this parasite. Both techniques used in this study represent a viable tool for ecoepidemiological studies, and can be used to produce good estimates of prevalence and parasitaemic level of the infection, which inform for the implementation of strategies for the control of the disease.
伊氏锥虫是一种鞭毛原生动物，寄生在多种哺乳动物中，偶尔也包括人类。在南美洲，它感染马、牛、水牛、狗和野生动物，导致一种被称为“Mal de Caderas”的疾病，由于广泛的病理表现，造成了重大的经济损失。阿根廷是它分布的最南端。水豚（Hydrochoerus hydrochaeris）是一种大型啮齿动物，分布于南美洲的热带至温带淡水湿地。由于感染伊氏锥虫的水豚没有任何疾病的临床症状，能够承受高寄生虫血症，因此该物种被提议为储存宿主。在这项研究中，我们使用涂片显微镜和实时 PCR 检测，调查了来自伊斯特罗斯德尔伊贝拉（阿根廷东北部科连特斯省）的 60 只自由放养的水豚样本中伊氏锥虫的流行率和寄生虫血症强度。所有感染伊氏锥虫的水豚都是在研究期间的一年中发现的，没有季节性的证据。总感染率为 10%，但在不同年份之间，感染率从 0%到 17%不等（2011 年）。这是首次通过分子生物学技术确认阿根廷存在伊氏锥虫感染。我们的研究结果表明，在检测水豚中伊氏锥虫的存在时，两种方法之间没有差异，这表明简单的方法，如显微镜检查，可以为该寄生虫的生态流行病学提供重要数据。本研究中使用的两种技术都是可行的生态流行病学研究工具，可以用来对感染的流行率和寄生虫血症水平进行良好的估计，为疾病控制策略的实施提供信息。
