淮河水系毛毕吸虫的研究初报

目的调查淮河水系有无毛毕属吸虫存在及其尾蚴性皮炎而行。方法现场采集耳萝卜螺（Radixauricularia），用直接压片法分离尾蚴，并感染雏鸭；采集渔民养殖家鸭的粪便，分别用水洗沉淀法检查虫卵和孵化法分离毛蚴，并用此毛蚴感染实验室饲养的耳萝卜螺；解剖沿岸渔民放养的家鸭及人工实验感染的雏鸭分离成虫，并对该成虫作扫描电镜观察；对沿岸部分村民作现场查询和体检，以确定有无该皮炎表现及伴随症状。结果从现场捕获的耳萝卜螺体内可分离到有眼点的叉尾蚴，经鉴定为毛毕属吸虫尾蚴。从渔民养殖家鸭的粪便内可检获到虫卵，该卵可孵出毛蚴；毛蚴感染实验室内饲养的耳萝卜螺，可获与上述形态相同的有眼点的叉尾蚴。解剖上述两个不同来源的家鸭均可获毛毕属吸虫成虫。该毛毕吸虫经电镜观察发现其形态特征与毛毕属吸虫其它近似种有所不同，因此，暂名为淮南毛毕吸虫。结论淮河水系有毛毕属吸虫存在，其尾蚴可引起皮炎。

AN EPIDEMIOLOGICAL SURVEY OF SCHISTOSOME CERCAIAL DERMATITIS AMONG THE RESIDENTS NEAR THE BANKS OF THE HUAIHE RIVER SYSTEM

Objective To make an epidemiological survey of schistosome cercaria and its der matitis among the local residents near the banks of the Huaihe river system. Methods On Huaihe riverside Radix auricularia were collected, the cercariae from them were separated, and infected the ducklines. The feces of the ducks bred by fishermen were collected, the eggs and miracidia from the feces were obtained by precipitate-hatching method. The Radix auricularia were experimentally infected with the miracidia. The adult worms were separated from the ducks bought from fishermen and the experimental ducklines, and viewed by scanning electron microscope. The signs and symp tomes of schistosome cercarial dermatitis in the residents (fishermen and peasents) on the Huaihe river bank were inquired and examined. Results The results showed that the cercariae discovered from Radix auricularia on Huaihe riverside natural environment belong to the specles of Trichobi harzia by identiflcation of the characteristics of the cercarlae with eye spot. The eggs from feces of the ducks bred by fishermen could be hatched to miracidia. the miracidia could infect Radix auricu laria experimentally. The cercariae with eye spot obtained from the experimaental infected Radix auricularia were the same with that from natural Radix auricularia. The adult worms of Trichobi harzia could be obtained from both the ducks bred by fishermen and experimental infected duck lines. But the morphological characteristics of the adult worm vlewed by electron microscpoe were different from that of the other specles of Trichobiharzia. A kind of schistosome dermatitis (locally called as "duck itch") was discoved among the residents on the Huaihe river banks. when they con tacted the water. Conclusion There is a schistosome cercarial dermatitis caused by a species of Tri chobiharzia among residents on the banks of Huaihe river sysiem.