卫氏并殖吸虫，又称卫氏肺吸虫，其成虫寄生于宿主肺内，引起肺吸虫病(paragonimiasis)。人的感染多因生食含囊蚴的溪蟹、喇蛄所致。本病分布广泛，我国有23个省、区有本病流行。
一、形态
1. 成虫
Paragonimus westermani.
showing the finely branched vitelline glands extending from the anterior to the posterior end. The ovary and testes are in the center. ×6. Enlarged by 5.4
Paragonimus sp from the lungs of an infected animal.
The parasites are fleshy worms with convex surfaces. The sides appear dark because of the presence of vitelline glands.
（1)长7.5-12mm,宽4-6mm,厚3.5-5mm，体肥厚，活体呈红褐色，背面稍隆起，腹面扁平。
（2)并列：子宫与卵巢；一对睾丸；一对卵黄腺。
2. 虫卵 金黄色，卵壳厚，卵盖明显，对端明显增厚。
A freshly passed egg of Paragonimus sp showing the distinct operculum and a thick shell. It is unembryonated at this stage. ×100. Interference contrast. Enlarged by 5.4.
二、生活史
1. 人或动物因食入含囊蚴的溪蟹、喇蛄感染。
2. 童虫、成虫的移行和寄居引起肺吸虫病，除肺部病变外，可累及全身多种器官。
3. 痰中虫卵被吞入消化道后可从粪便排出。
4. 中间宿主：川卷螺→溪蟹、喇蛄
5. 保虫宿主：多种家畜（如：狗、猫等)和一些野生肉食动物（如虎等)
川卷螺
溪蟹、喇蛄
Potamon sp, a crab host of Paragonimus.
This is a fresh water crab and is sometimes eaten raw when is could transmit infection.
三、致病
