Intestinal flukes of genus Metagonimus and their second intermediate hosts in Kangwon-do

Abstract

This study investigate the epidemiological feature of Metagonimus infection in Kangwon-do (province). The average infection rate of the surveyed inhabitants was 7.8% (83 positives out of 1, 067 examinees) by stool examination; male, 11.4% and female, 3.2%, respectively. The egg positive rate in residents in the Som river area was 7.3%, that of the Chuchon river area 6.3%, the Pyongchang river area 12.8%, the Tong river area 3.8%, the Hongchon river area 9.8%, and the Ohsip stream area of Samchok 8.0%, respectively. The average metacercarial infection rate of genus Metagonimus in the fish was 81.0% (256 positives out of 318 fish). The infected fishes were Zacco platypus, Zacco temmincki, Opsariichthys bidens, Squalidis sp., Carassius carassius, etc. in western Kangwon-do Meanwhile, in the Ohsip stream area of Samchok-gun, eastern costal Kangwon-do, the infected fish were Plecoglossus altivelis and Tribolodon hakonensis. The rats and dogs are infected with the metcercariae obtained from Zacco platypus and Opsariichthys bidens, adult worms collected were Miyata type of Metagonimus with some M. takahashii. When infected with metacercariae from Plecoglossus altivelis, Metagonimus yokogawai was only found. M. yokogawai and Metagonimus Miyata type were found together in Tribolodon hakonensis in Ohsip stream area of Samchok, in the eastern Kangwon-do. The intestinal flukes of genus Metagonimus in western Kangwon-do were Miyata type of Metagonimus and M. takahashii, transmitting mainly by Zacco platypus and Opsariichthys bidens as a source of infection. In the eastern part of Kangwon province (Ohsip stream area of Samchok), M. yokogawai was mainly distributed by P. altivelis and T. hakonesis, but some T. hakonensis harbored the metacercariae of Miyata type of Metagonimus with those of M. yokogawai.