Abstract
During the period from July, 1979 to May, 1981, the freshwater crab, Geothel-phusa dehaani, which is known as the second intermediate host of the lung fluke, Paragonimus westermani, was collected at 16 different localities in Higashi-Yoshino area of Nara Prefecture. A total of 4, 833 crabs were examined for the metacercariae of P. westermani. At the 5 localities, a total of 290 metacercariae of the lung fluke were obtained from 172 (6.1%) of 2, 812 crabs captured. The number of metacercariae per positive crab varied from 1 to 13, with an average of 1.7. No metacercarial infestation was found in 2, 021 crabs at the remaining localities. On the basis of the morphological features of the metacercariae, as well as the adults and their eggs recovered from the experimental cats, all the Paragonimus metacercariae collected in this investigation were identified as the metacercariae of the "Original type" of P. westermani (Kerbert, 1878) as proposed by Miyazaki. Based on the present results, Higashi-Yoshino area of Nara Prefecture has to be added to the list of prevalent areas of this lung fluke in Japan.
