ObjectiveTo observe the effe ct of varnish“Fangyouling” preventing skin invasion from Schist osoma cercariae. MethodsThe“Fangyouling” was made from niclo s amide and permeable improver, and the concentration of the drug was 1%-2%. Exper imenta l mice and rabbits were spread with “Fangyouling” on the abdomen skin without h air at day 1,2,3,4,5,6,7 respectively before infection, compaired with cont rol group. ResultsThe worm reduction rates of mice which were spread with drug 1-4 days and 5-7 days before infection were 100 % and 99 7%-88 1%. The worm reduction rates of rabbits which were spread with dr ug 3-7 days before infection were 86 4%-80 1%. ConclusionThe“Fangyouling” has long efficiency on preventing Schistosoma cercariae from invading skin.

Objective To study the effect o f levamisole against the invasion of Schistosoma japonicum cercariae. Methods Mice infected wit h Schistosoma cercariae were administered orally with levamisole hydrochloride or alkali levamisole two days before the infectio n at a dose of 26.25 mg/kg for 7 days. The liniments of levamisole hydrochlorid e and alkali levamisole were embrocated on the mouse skin two days, one day and 0 day before the infection respectively, and the concentrations of the drug were 1%, 2%, 3%, 5% and 7% respectively. The experimental animals were dissected 4 we eks after the treatment and adult worms were collected. Results The worm reduction rates of mice administered orally with leva misole hydrochloride or alkali levamisole were both 0. The worm reduction rates were both 100% when the mice were embrocated with 5% levamisole hydrochloride on the infection day or with 7% levamisole hydrochloride one day before the infect ion. The worm reduction rates were all 100% when the mice were embrocated with 2 %, 3% or 5% alkali levamisole one day before the infection. Conc lusions Levamisole liniments can prevent from S . japonicum cercaria infection, and alkali levamisole is better th an levamisole hydrochloride. When levamisole is given orally, no effect was show n.