Departments of Internal Medicine and Epidemiology, University of Iowa, Iowa City, IA, USA.
Adv Parasitol. 2011;75:1-18. doi: 10.1016/B978-0-12-385863-4.00001-0.
Trypanosoma cruzi, the cause of American trypanosomiasis, or Chagas disease, is a protozoan parasite that is enzootic and endemic in much of the Americas, where it infects a wide variety of wild and domestic mammals as well as many species of triatomine vectors, in addition to humans. Historically, vector-borne transmission of T. cruzi has been the most important mechanism through which humans have become infected with the parasite, but transmission by blood transfusion and congenital transmission also have been important. In many of the endemic countries transmission of T. cruzi has improved markedly in recent years as vector control and donor screening programs have been implemented on a widespread basis. In the United States autochthonous transmission of T. cruzi appears to be extremely rare. Five persons are known to have become infected with T. cruzi through organ transplants here, and prior to the implementation of blood donor screening in 2007 five instances of transmission by transfusion had been reported. Current estimates put the total number of T. cruzi-infected persons living in the United States at 300,000, essentially all of whom are immigrants from the endemic countries. The obstacles that stand in the way of the total elimination of T. cruzi transmission throughout the endemic range are economic and political, and no major technological advances are needed to accomplish this goal.
克氏锥虫，即造成美洲锥虫病（恰加斯病）的病原体，是一种原生动物寄生虫，在美洲大部分地区呈地方性流行，感染范围广泛，包括多种野生动物和家养哺乳动物，以及多种三锥虫媒介，此外还感染人类。从历史上看，通过媒介传播是人类感染克氏锥虫的最重要机制，但输血传播和母婴垂直传播也很重要。在许多流行地区，随着广泛实施媒介控制和献血者筛查计划，近年来克氏锥虫的传播已明显改善。在美国，克氏锥虫的本地传播似乎极为罕见。已知有 5 人因器官移植而感染克氏锥虫，在 2007 年实施献血者筛查之前，已有 5 例因输血传播的病例报告。目前估计，生活在美国的克氏锥虫感染人数为 30 万，他们基本上都是来自流行地区的移民。在整个流行地区彻底消除克氏锥虫传播的障碍是经济和政治方面的，不需要重大技术进步就可以实现这一目标。
