THE EFFECT OF VARIATION IN MIRACIDIAL EXPOSURE DOSE ON ESPERIMENTAL INFECTIONS OF FASCIOLA GIGANTICA IN LYMNAEA GEDROSIANA

Abstract

The laboratory infection of Lymnaea gedrosiana with 2,5 and 10 miracidia of Fasciola gigantica resulted in infection rates of 20%, 40% and 69%, respectively, with a prepatent Period of 66-88 days. There was a significant difference in infection rate between the snails infected with 2 and those with 10 miracidia (P<0.05). At 92 days post- infection there was 25% to 33.3% of live snails still harboring immature stages of F.gigantica larvae. The mortality rate of the infected and non-infected control groups showed no marked differences.