Decrease of Metagonimus yokogawai Endemicity along the Tamjin River Basin

Abstract

Abstract:The Tamjin River which flows from Jangheung-gun via Gangjin-gun to the South Sea was reported to be a highly endemic area of Metagonimus yokogawai infection in 1977 and 1985. However, there were no recent studies demonstrating how much change occurred in the endemicity, in terms of prevalence and worm burden, of metagonimiasis in this river basin. Thus, a small-scale epidemiological survey was carried out on some residents along the Tamjin River basin in order to determine the current status of M. yokogawai infection. A total of 48 fecal samples were collected and examined by the Kato-Katz thick smear and formalin-ether sedimentation techniques. The egg positive rate of all helminths was 50.0%, and that of M. yokogawai was 37.5%, followed by C. sinensis 22.9% and G. seoi 4.2%. To obtain the adult flukes of M. yokogawai, 6 egg positive cases were treated with praziquantel 10 mg/kg in a single dose and purged with magnesium sulfate. A total of 5,225 adult flukes (average 871 specimens per person) of M. yokogawai were collected from their diarrheic stools. Compared with the data reported in 1977 and 1985, the individual worm burdens appeared to have decreased remarkably, although the prevalence did not decrease at all. It is suggested that the endemicity of M. yokogawai infection along the Tamjin River has been reduced. To confirm this suggestion, the status of infection in snail and fish intermediate hosts should be investigated.

Prevalence ofClonorchis sinensisMetacercariae in Freshwater Fish from Three Latitudinal Regions of the Korean Peninsula

“…The endemicity was relatively higher in fishes from 5 localities except Jangheung-gun. Especially, it is interesting to note that the endemicity of C. sinensis in fishes from Gangjin-gun is high, because Gangjin-gun has been well known as a highly endemic area of metagonimiasis [ 33 , 34 ].…”

Foodborne Intestinal Flukes in Southeast Asia

“…The Sumjin, Tamjin, and Boseong Rivers, Geoje Island, and Osip Stream (Gangwon-do) were the highest endemic areas with 20-70% egg positive rates in the villagers [2,222,224,225]. The high prevalence of M. yokogawai along the Tamjin River basin is persisting, although the intensity of infection among the villagers has been reduced [226]. Human infections have also been found in Guangdong, Anhui, Hubei, and Zhejiang provinces of China and Taiwan [6,183].…”

Infection characteristics of Metagonimus species (Digenea: Heterophyidae) metacercariae in fish from major rivers of Korea

“…These flukes casue an important food-borne zoonotic disease in Korea [ 2 , 10 , 11 ]. Especially, infections by M. yokogawai are mainly prevalent in the riverside areas of eastern and southern coast of Korean peninsula [ 14 – 20 ]. Human cases by M. takahashii were first reported in inhabitants of Eumseong-gun (gun=county), Chungcheongbuk-do (do=Province), along the upper reaches of the Namhan-gang (gang means river) [ 21 ].…”

“…The crusian carp, common carp ( Cyprinus carpio ), sea rundace, and Japanese seabass were reported as second intermediate hosts of M. takahashii [ 15 , 18 , 19 ]. Many species of fish including the sea rundace and chubs were listed as second intermediate hosts of M. miyatai in Korea [ 15 , 18 , 20 ].…”

“…The riverside areas of Tamjin-gang have been known as the endemic area of intestinal fluke including Metagonimus spp. and heterophyid flukes [ 2 , 14 , 20 , 51 – 54 , 63 ]. Chai et al [ 14 ] reported 26.4% prevalence of metagonimiasis from 606 residents in the riverside areas of Tamjin-gang.…”