Studies on intestinal trematodes in Korea XIII. Two cases of natural human infection by Heterophyopsis continua and the status of metacercarial infection in brackish water fishes

Abstract

Two cases of natural human infection by Heterophyopsis continua (Heterophyidae) were identified by collection of adult worms in 1983 in Korea. And in order to know the source of infection a study on fish intermediate hosts was performed along the southwestern coastal areas. The cases were 24 and 50-year old males residing in southern coastal areas. They had the clinical complaints of non-specific gastrointestinal symptoms such as epigastric pain and one of them also complained the discharge of tapeworm segments. Praziquantel in single dose of 10~15 mg/kg was given followed by purgation with mangnesium salt and 2 and 46 specimens of H. continua were collected from the diarrheal stools. They said to have eaten raw flesh of several kinds of brackish water fishes. The results of fish examination for metacercarial infection were as follows: Seventeen (63.0%) out of 27 perches (Lateolabrax japonicus) and 10 (29.4%) out of 34 gobies (Acanthogobius flavimanus) harboured the metacercariae but none of 42 mullets (Mugil cephalus) were found to harbour them. The average metacercarial density in perches was 55.4 and 18.7 per fish respectively. And the majority of the metacercariae were collected from the muscle of body portions in these fishes. After the metacercariae were experimentally fed to two rats and one young dog, two adult worms were recovered from the dog while none from the rats. These worms were also indentified as H. continua. From the results it was concluded that the brackish water fishes which the human cases said to have eaten were the source of infection.

Prevalence of Zoonotic Metacercariae in Two Species of Grouper, Epinephelus coioides and Epinephelus bleekeri, and Flathead Mullet, Mugil cephalus, in Vietnam

“…In the Republic of Korea, the intestinal fluke Pygidiopsis summa is found in mullets (Mugil cephalus) and gobies (Acanthogobius flavimanus) along the coastal areas [13] and H. continua is recorded from perch, goby, and shad; these fluke species have all been documented to cause human infections [14,15]. Chai [15] provides estimates that there are 10,000 cases of H. continua and 50,000 cases of P. summa in Korea.…”

Heterophyid metacercarial infections in brackish water fishes from Jinju-man (Bay), Kyongsangnam-do, Korea

“…Previously, the common carp, Cyprinus carpio, the crussian carp, Carassius auratus, and the dace, Tribolodon taczanowskii, have been reported to be intermediate hosts of M. takahashii (Chai and Lee, 2002 (Kanemitsu et al, 1953;Chun 1960;Komiya, 1965;Kobayashi, 1968;Seo et al, 1984;Sohn et al, 1994;Kim et al, 1996;Sohn and Moon, 2001;Sohn et al, 2005). Among these, M. cephalus, L. japonicus, A. flavimanus, K. punctatus, P. altivelis, C. myriaster, B. pectinirostris and Scartelaos sp.…”

“…In terms of sources of infection, several kinds of brackish water fish, such as, perch (Lateolabrax japonicus), shad (Konosirus punctatus), mullet (Mugil cephalus), and goby (Acanthogobius flavimanus), have been identified in Korea (Chun 1960(Chun , 1963Seo et al, 1980Seo et al, , 1981Seo et al, , 1984Chai and Sohn, 1988;Chai et al, 1989;Sohn et al, 1994;Sohn and Moon, 2001). These fish are sometimes heavily infected with the metacercariae of heterophyid flukes, and are popularly eaten raw by residents in coastal areas.…”

Prevalence of Heterophyes Nocens and Pygydiopsis Summa Infections Among Residents of the Western and Southern Coastal Islands of the Republic of Korea

“…Other heterophyid flukes collected included Heterophyopsis continua 5 (4 specimens), Stellantchasmus falcatus 6 (5), Stictodora fuscata 4,7 (134), and S. lari 8 (5). Flukes of the other families were also collected, namely, G. seoi (6,914) ( Figure 3A) and Acanthoparyphium tyosenense 24 (1) (Echinostomatidae) ( Table 2).…”

“…1,2 Among these, 10 species, namely, Metagonimus yokogawai, M. takahashii, M. miyatai, Heterophyes nocens, Heterophyopis continua, Centrocestus armatus, Pygidiopsis summa, Stellantchasmus falcatus, Stictodora fuscata, and S. lari have been reported to be indigenous in the Republic of Korea. [3][4][5][6][7][8] Because of its wide geographic distribution and high prevalence in riverside areas, public health attention has focused upon M. yokogawai. 3,4 However, with regard to the other heterophyids, particularly H. nocens and P. summa, which are distributed in brackish water areas, [9][10][11][12][13] comparatively little has been done to determine their geographic distributions and prevalences.…”