Dubey J P
United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, MD 20705-2350, USA.
Food Waterborne Parasitol. 2022 Dec 9;30:e00184. doi: 10.1016/j.fawpar.2022.e00184. eCollection 2023 Mar.
Infections with the lung fluke, have been diagnosed in a variety of domestic and wild animals and humans in USA and Canada. Although there are many species of in other parts of the world; is the only species definitively diagnosed in USA and Canada. Fresh water snails (several species) and crayfish (mainly spp.) are its intermediate hosts. Humans and animals become infected with only by ingesting metacercariae encysted in the heart of crayfish. After ingestion, the fluke penetrates intestinal wall, enters peritoneal cavity, and reaches pleural cavity by direct penetration of diaphragm, 2-3 weeks post inoculation (p.i.). Young flukes penetrate lungs and become encysted in pulmonary tissue, often in pairs. Time to maturity is around 4-7 weeks p.i. Eggs are coughed up, swallowed, and are excreted in feces. Although the parasite has been known for more than a century, there has been an upsurge of human infections in the USA. Here, I review infections in naturally infected hosts. Pathogenesis, diagnosis, and treatment in parasite-free cats and dogs experimentally infected are reviewed to shed light on the pathogenesis of human paragonimiasis. Problems and challenges facing diagnosis of paragonimiasis, especially non-pulmonary infections, are discussed. Fluke stages are deposited in Smithsonian Museum.
在美国和加拿大，多种家畜、野生动物及人类已被诊断出感染肺吸虫。尽管在世界其他地区存在多种肺吸虫；但在美国和加拿大确诊的只有这一种。淡水螺（多种）和小龙虾（主要是螯虾属物种）是其中间宿主。人和动物只有通过摄入包裹在小龙虾体内的后尾蚴才会感染肺吸虫。摄入后，吸虫穿透肠壁，进入腹腔，并在接种后2 - 3周通过直接穿透膈肌到达胸腔。幼吸虫穿透肺部并常常成对地在肺组织中形成包囊。感染后4 - 7周左右发育成熟。虫卵被咳出、吞咽后随粪便排出。尽管这种寄生虫已被发现一个多世纪，但美国的人类感染病例却呈上升趋势。在此，我回顾自然感染宿主中的肺吸虫感染情况。为了阐明人类肺吸虫病的发病机制，对无寄生虫的猫和狗实验感染肺吸虫后的发病机制、诊断和治疗进行了综述。讨论了肺吸虫病诊断面临的问题和挑战，尤其是非肺部感染的情况。吸虫标本保存在史密森尼博物馆。
