[Infectivity difference between mice challenged by the laboratory-cultivated and field collected Schistosoma japonicum-infected Oncomelania hupensis].

OBJECTIVE: To explore the infectivity difference between the mice challenged by laboratory-cultivated and field collected Schistosomajaponicum-infected Oncomelania hupensis snails. METHODS: A total of 120 Kunming mice were randomly divided into two groups. S. japonicum-infected O. hupensis releasing cercariae was according to routine cercaria shedding method. Each mouse was challenged by 40 cercariae. The worm-load, the development rate, EPG of liver and EPG of feces in the mice were calculated. RESULTS: The mean worm-load, adult worm development rate, EPG of liver and EPG of feces in the group of mice infected by field collected S. japonicum-infected snails were 27.43 +/- 3.78, 68.53 +/- 9.44, 19 800.97 +/- 6 752.59 and 196.37 +/- 11.56, respectively, which were significantly higher than those in the group challenged by cercariae from laboratory-cultivated S. japonicum-infected snails (23.93 +/- 4.93, 59.83 +/- 12.32, 5 803.69 +/-1 560.49 and 107.73 +/- 10.32) (P < 0.05). The mean worm-load, adult worm development rate and EPG of liver in the male mouse group were higher than those in the female mouse group (P < 0.05). CONCLUSION: The cercariae released from field collected S. japonicum-infected snails have more aggressive infection ability, compared with the cercariae released from the laboratory-cultivated S. japonicum-infected snails and the results also show male mice are more susceptibility to the schistosome infection than female mice.