淮河水系毛毕吸虫自然疫源地调查报告

目的 调查淮河水系是否存在毛毕属吸虫及其尾蚴性皮炎流行。方法 取现场采集和实验室感染的耳萝卜螺压片、镜检，分离母胞蚴、子胞蚴和尾蚴，并将分离获得的尾蚴接种雏鸭；收集淮河沿岸家鸭和人工感染的雏鸭粪便，用水洗沉淀法查找虫卵、孵化分离毛蚴，并用此毛蚴感染实验室饲养的耳萝卜螺；解剖家鸭和人工感染的雏鸭分离成虫。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 现场采集耳萝卜螺的感染率为0．39％（71／18000）；家鸭粪便毛毕吸虫卵阳性率为33．50％（201／600），雏鸭接种23d后，从粪中可查见虫卵，且所获虫卵可孵化出毛蚴；解剖部分虫卵阳性家鸭和经尾蚴感染的雏鸭可分离出成虫。从虫卵、毛蚴、尾蚴及成虫形态观察，均属毛毕属吸虫。沿岸村民接触有鸭活动的水体后，在胸腹部及下肢等处皮肤可见弥漫性突出皮肤的红色丘疹，周围有红晕，并可见成片的风疹团，患处刺痒或奇痒。结论 淮河水系存在毛毕属吸虫，并有血吸虫尾蚴性皮炎流行。

Survey on natural focuses of Trichobilharzia in Huaihe River Basin

Objective To investigate the existence of Trichobiharzia in Huaihe River and the prevalence of its dermatitis.Methods The mother sporocyst,daughter sporocyst and cercaria in Radix auricularia were isolated by tabletting.The brood ducks were experimentally infected with the cercaiae.The eggs and miracidia of Trichobiharzia were collected by precipitate-hatching from dung of the ducks and brood ducks.The R.auricularia were experimentally infected with the miracidia.Adult worms were separated from the ducks bought from fishermen and the experimental brood ducks.The signs and symptoms of cercarial dermatitis among the residents(fishermen and peasants) on the Huaihe River Basin were inquired and examined.Results The average detection rate of the mother sporocyst,daughter sporocyst and cercaria from R.auricularia was 0.39%(71/18 000).33.50%(201/600) ducks were eggs of Trichobiharzia positive in stool.The eggs could be detected in the dung of ducks infected 23 days before,and the eggs could be hatched to miracidia.The adult warm could be isolated from the ducks naturally infected and brood ducks infected by the cercariae with eye spot.The eggs,miracidia,cercaria and adult worms belonged to the species of Trichobiharzia identified by the morphological characteristics.Diffuse erythema or popular eruptions with red areolae were appeared on the skin of chest,abdomen and legs among the residents contacting with the polluted water.Conclusions Epidemics of Trichobiharzia and schistosome cercarial dermatitis are existent in Huaihe River Basin.