A human case of Centrocestus armatus (Heterophyidae) infection was proved by identifying an adult worm collected after treatment with praziquantel in Korea. The case is 42-year old man who resides in a rural area in Sanchung-gun, Kyeongsangnam-do. The case was concomitantly infected with Clonorchis sinensis and had the history of eating raw freshwater fishes including Zacco platypus, which are known to be the second intermediate host of C. armatus in Korea.. This is the first report of natural human infection by C. armatus in the literature.
parasitology-helminth-trematoda ; Centrocestus armatus ; intestine ; Heterophyidae ; Clonorchis sinensis ; case report

In an attempt to determine the incidence of the cercarial larvae of trematodes, Semisulcospira snails collected in Judong stream, an endemic area of Paragonimus westermani, in Kyungpook Province, Korea, were examined from 1965 to 1980. The infestation rate for cercariae in the snails was 5.4 per cent, but in 1970 dropped to 4.0 per cent and remained at the same level, 4.2 per cent, in 1975. It then decreased to 3.5 per cent in 1980. Seven species of cercariae, Cercaria incerta(Kobayashi, 1992) Faust, 1924, Cercaria nipponensis(Ando, 1915) Faust, 1924, Cercaria yoshidae(Osafune, 1898) Cort et Nichols, 1920, Centrocestus armatus(Tanabe, 1922) Yamaguti, 1934, Metagonimus species, Notocotylus magniovatus Yamaguti, 1934, and Paragonimus westermani(Kerbert, 1878), and five kinds of undeterminced cercariae were found. Of these, the most freqently emerged cercaria was Metagonimus species, folllowed by Notocotylus magniovatus. The least freqently emerged was Paragonimus westermani, with the rate of 0.04 per cent. The liberation rates in the five kinds of undetermined species varied from 0.04 to 0.15 per cent. In the monthly liberaton rates for cercariae, the highest rate was encountered in May, and decreased in the period from June to November. It then somewhat increased again in December. There was no correlation in the liberation rate for cercariae and length of snails. The results of this study indicate that the infestation of Semisulcospira snails with the cercariae of trematodes has decreased over the fifteen year period from 1965 to 1980.
parasitology-helminth-trematoda ; Semisulcospira sp. ; Paragonimus westermani ; Cercaria incerta ; Cercaria nipponensis ; Cercaria yoshidae ; Centrocestus armatus ; cercaria ; epidemiology

In order to clarify infestation pattern for the encysted larvae of digenetic trematodes from fresh-water fishes, this survey was carried out from March to September, 1983. A total of 380 fishes of 32 species were collected with netting at the three reaches, upper, middle and lower in Mangyeong riverside area. After the fishes were dissected into small scraps, they were pressed under cover glass and examined for the presence of those of digenetic trematodes with a microscope. The results obtained were as follows: Out of a total of 380 fishes inspected, 320 fishes (84 percent) from 31 species were found positive with digenetic trematode metacercariae; more than 10 species of the metacercariae were detected in Pseudorasbora parva; Gnathopogon majimae, Microphysogobio yaluensis, Cultriculus eigenmanni and Gnathopogon coreanus (more than 8 species); Aphyocypris chinensis(8 species) and etc. respectively. Clonorchis sinensis metacercariae were found positive from 93 fishes (25 percent) from 12 species detection rates in other species of digenetic trematode metacercariae from various fishes were; Exorchis oviformis, 261 fishes (57 percent) from 28 species; Cyathocotyle orientalis, 47 fishes (12 percent) from 12 species; Metorchis orientalis, 21 fishes (6 percent) from 12 species; Metagonimus yokogawai, 164 fishes (43 percent) from 26 species; Pseudexorchis major, 71 fishes (19 percent) from 18 species; Metacercaria hasegawai, 77 fishes (20 percent) from 25 species; Centrocestus armatus, 24 fishes (6 percent) from 7 species; Echinochasmus japonicus, 2 fishes (0.5 percent) from 2 species, and unidentified species, 34 fishes (9 percent) from 15 species respectively. The sums of average number of the encysted larvae of all species found in fish body/gram showed 83 in P. parva, Cobitis taenia (74.2), A. chinensis (28.5), Pseudoperilampus uyekii (26.6), G. majimae (19.6) and etc. respectively and the average peak number of each metacercaria in fish body/gram showed 21.7 C. sinensis, 24 E. oviformis , 15.3 M. orientalis and 6.1 E. japonicus in P. parva ; 42.7 C. orientalis and 25.1 M. yokogawai in C. taenia; 8.3 C. armatus and 8.3 M. hasegawai in P. uyekii; 6.3 P. major in Carassius carassius, and 2.9 unidentified species in G. majimae respectively.
parasitology-helminth-trematoda ; Clonorchis sinensis ; epidemiology ; Pseudorasbora parva ; Gnathopogon majimae ; Microphysogobio yaluensis ; Cultriculus eigenmanni ; Gnathopogon coreanus ; Aphyocypris chinensis ; Cyathocotyle orientalis ; Metorchis orientalis ; Exorchis oviformis ; Metagonimus yokogawai ; Pseudexorchis major ; Metacercaria hasegawai ; Centrocestus armatus ; Echinochasmus japonicus