After 3 days of refrigeration prior to pla-som preparation, about 50% of
metacercariae were found to be degenerated (Fig. 2B) and were unable
to infect the hamsters (Fig. 2C), indicating that low temperature might
have affected infectivity of OVMC, in a similar manner as in other
trematodes (Boray and Enigk, 1964; Ferrell et al., 2001).