Farag H F, el Sayad M H, Osman M M
Parasitology Department, Alexandria University, Egypt.
J Trop Med Hyg. 1995 Dec;98(6):428-30.
A metacercarial precipitin test was devised for diagnosis of human fascioliasis. The sera tested were those of cases of fascioliasis (acute and chronic), of schistosomiasis and of normal healthy individuals. Metacercariae were prepared in the laboratory from naturally infected snails. Serum dilutions of 1:5 (20%) and 1:10 (10%) were incubated with metacercariae for periods of 6, 24 and 48 hours. No precipitation was observed when the sera of healthy persons were used. With sera of fascioliasis cases a precipitate was formed which increased in amount with time. It was more rapid in its formation and greater in its quantity with sera of acute fascioliasis. When incubation was prolonged a free precipitate was seen in the medium. With sera of schistosoma cases, a precipitate was observed in a few cases only; it was negligible in amount and localized to the plug area. Metacercarial precipitin is considered a simple, sensitive and specific test for diagnosis of human fascioliasis. It is recommended to use the serum in a dilution of 1:5 (20%), to give preliminary results after 6 hours incubation and to confirm 24 hours later.
为诊断人体片形吸虫病设计了一种后尾蚴沉淀试验。检测的血清来自片形吸虫病（急性和慢性）、血吸虫病患者以及正常健康个体。后尾蚴是在实验室用自然感染的蜗牛制备的。将血清按1:5（20%）和1:10（10%）稀释后，与后尾蚴一起孵育6、24和48小时。使用健康人的血清时未观察到沉淀。片形吸虫病患者的血清会形成沉淀，且沉淀量随时间增加。急性片形吸虫病患者血清形成沉淀的速度更快、量更大。孵育时间延长后，培养基中可见游离沉淀。血吸虫病患者的血清仅在少数情况下观察到沉淀；沉淀量可忽略不计，且局限于塞子区域。后尾蚴沉淀试验被认为是诊断人体片形吸虫病的一种简单、灵敏且特异的试验。建议使用1:5（20%）稀释的血清，孵育6小时后得出初步结果，并在24小时后进行确认。
