The infectivity of Fasciola spp. to Wistar rats was evaluated with the
recovery rate and development of flukes. The recovery rate from the l
iver parenchyma and bile duct was 20.0-30.0% in F. hepatica, 36.6-47.5
% in Japanese Fasciola sp. and 0-5.0% in F. gigantica. Mature flukes w
ere first recovered at week 8 in F. hepatica and week 12 in Japanese F
asciola sp., however, F. gigantica did not mature in the rats examined
until 12 weeks after infection. These results suggest that F. hepatic
a and Japanese Fasciola sp. are high in infectivity to Wistar rats, wh
ereas F. gigantica is low.