美洲锥虫病——美洲新型艾滋病

American Trypanosomiasis,New AIDS of the Americas

美洲锥虫病,又称查加斯病,是由克氏锥虫引起的潜在致命的寄生虫性人兽共患病。除人外,在美洲200多种哺乳动物感染了克氏锥虫。人和动物感染的主要传播媒介为吸血昆虫——锥蝽,偶尔通过非吸血昆虫媒介机制传播,如输血、污染食品、母婴感染。该病的临床症状因感染阶段不同而异,早期急性期无症状或症状轻微,隐匿期亦无症状,慢性期的典型症状为渐进性慢性心脏和消化系统损害,持续终生,部分病例死亡。因克氏锥虫与人免疫缺陷病毒(HIV)的早期传播模式、漫长的潜伏期和难以治愈等方面极其相似,有专家将查加斯病称为"美洲的新艾滋病"。该病曾局限于美洲地区,但现已随人口迁移传播到欧洲等大陆,成为全球性疫病。在急性期,使用苄硝唑和硝呋替莫抗寄生虫药物治疗很有效;在慢性期,也可延迟或防止症状恶化,但仍有部分慢性病例最终发展成致命的心脏和消化道衰竭。查加斯病可通过病原鉴定、血清学和分子学技术进行诊断。目前尚无查加斯病疫苗,媒介昆虫控制是最有效的预防手段。论文详细介绍了美洲锥虫病的病原学、生活史、流行病学、临床症状、病理变化、诊断、治疗以及防控措施,以供参考。

American trypanosomiasis, also termed Chagas disease, is a potentially fatal parasitic zoonosis caused by the flagellate protozoan Trypanosoma cruzi, which occurs in humans and over 200 species of mammals throughout the Americas. It is spread to humans and animals commonly by an insect vector, the blood-sucking triatomine bug of the subfamily Triatominae （family Reduviidae）, or occasionally by non- vectorial mechanisms, such as blood transfusion, ingestion of contaminated food or mother to infant. Clin- ical signs vary over the infection course： the initial, acute phase with absent or mild symptoms; asympto- matic intermediate or indeterminate phase of varying length; and chronic phase with the symptoms of grad- ual chronic damage in heart and digestive system through lifetime, and eventual death. Because of similari- ties to early spread, long incubation period and difficult cure of HIV, Chagas disease has been named ＂the new AIDS of the Americas＂. The disease was once entirely confined to the Americas, but it is now consid- ered a globalized disease due to spread with immigration to other continents, such as Europe. Antiparasitic treatment using benznidazole and nifurtimox is urgently indicated in the acute phase. The treatments also appears to delay or prevent progression of disease symptoms during the chronic phase, but some chronical cases will still finally develop lethal heart and digestive system failures. Chagas disease can be diagnosed by pathogen identification, serology and molecular techniques. There is no vaccine available for Chagas dis- ease. Vector control is the most effective method for preventing Chagas disease. The paper reviewed the e- tiology, life cycle, epidemiology, symptoms, pathology, diagnostical tests, treatment and prevention of American trypanosomiasis.