A 32-year-old housewife who resides in Taegu was admitted in Yeungman University Hospital due to right upper quadrant abdminal pain of 2 mounths'duration. An abdomical CT and ultrasonography revealed a relatively well demarcated low density mass in the right lobe of liver. Right hepatic lobectomy was performed on the clinical impression of hepatoma. On the light microscopic study, the lobulated liver mass showed extensive central necrosis and fibrosis, with large numbers of pseudotubercles therein. The pseudotubercles have distorted helminthic eggs frequently. The submitted common bile duct lymph node also showed a few pseudotubercles. The eggs recovered from the tissue homogenate measured 140~152 micrometer by 75~85 micrometer in size and were unembryonated and light yellow to brown. The eggs were determined as those of Fasciola species. We reported the present case as 11th one of human fascioliasis in korea.
Humans

In an attempt to determine the susceptibility of inbred golden hamsters(Mesocricetus auratus) to the experimental infection with Clonorchis sinensis, twenty-five hamsters were divided into 5 groups and administered orally 5, 10, 20, 30 or 50 metacercariae each. The hamsters were killed on the 45th day after infection. The adult flukes were recovered from all hamsters. The overall recovery rate for the fluke was 57.9 percent with the range of 48.4 percent to 92.0 percent. As the number of the metacercariae given increased, a proportionate decrease in the recovery rate was found. The prepatent period of the fluke in the hamster varied from 16 to 17 days, with the average of 16 days. No significant differences in the development of the flukes were observed. Egg production expressed by EPG, increased step by step as the time elapsed. However, a tendency of decreasing egg laying capacity was observed with the increase of worm burden. It is suggested that the hamster is a suitable final host of C. sinensis.
parasitology-helminth-trematoda ; Clonorchis sinensis ; clonorchiasis ; susceptibility ; golden hamster

This study was undertaken to evaluate the role of peritoneal exudate cells in the transfer of immunity against the liver fluke, Clonorchis sinensis in the inbred BALB/c mice. Ten donor mice were divided into 2 groups. One group consisted of 5 mice was infected orally with 20 metacercariae of C. sinensis, and the other group was injected intraperitoneally with 20 excysted larvae. Thirty days after immunization, the peritoneal exudate cells were obtained from the donor mice. Twenty recipient mice were divided into 4 equal groups for the purpose of primary immunization. The mice of Group I were injected intraperitoneally with 2 x 10(6) peritoneal exudate cells of the donor mice infected orally, those of Group III were injected intraperitoneally with 2 x 10(6) peritoneal exudate cells of the donor mice injected intraperitoneally. Those of Group II were injected orally with 20 metacercariae of C. sinensis. The group IV mice served as controls. Four days after the primary immunization all recipient mice were challenged orally with 20 metacercariae of C. sinensis, and then killed 30 days after the challenging infection. When the peritoneal exudate cells were injected into the recipient mice, pronounced reduction in eggs per gram of the feces was found in the mice of Group I and Group II, but no reduction in those of Group III. In the worm burdens of C. sinensis, the number of flukes found in the mice of Group II was only significantly less than those in the control group(IV). In addition the number of plaque forming cells per spleen in the mice of Group II was found larger than those in Group I. It is likely that donor peritoneal exudate cells transferred to the recipients might result in the production of relative immunity.
parasitology-helminth-trematoda ; Clonorchis sinensis ; immunology ; mouse

The species composition, population density, and seasonal prevalence of vector mosquitoes in an inland area of Kyungpook province were studied, based on light trap and human bait trap collections, and the recent patterns of infestation for infective larvae of Brugia malayi in these vector hosts were investigated from May to November in 1985. Nine species in four genera of mosquitoes were collected by light trap, human bait trap, and/or by nets. Anopheles sinensis Wiedemann was the most abundant species collected by light traps during this year. Culex tritaeniorhychus Giles was the second abundant species, and Aedes vexans nipponii(Theobald) ranked third in total abundance. The earlist time when A. sinensis were found was the middle of May. At that time the temperature ranged from 14.3 C to 22.8 C and the humidity 53-90 per cent. The month of highest average nightly catch was July, when the temperature was betweeen 21.5 C and 30.6 C and the humidity 72-91 per cent. The peak time of biting activity of mosquitoes was different in each month, i.e. between 22:00-23:00 in July, and 20:00-21:00 hours in September, when the temperature was between 24.3 C and 26.5 C and the humidity 73-88 per cent in the field. While infective larvae of B. malayi were reported to have been found in one species of mosquito in 1975, no larvae were found in any species collected in this survey.
parasitology-helminth-nematoda ; arthropoda ; Brugia malayi ; Anopheles sinensis ; epidemiology

A study of infestation patterns for larval trematodes from fresh-water fish and brackish-water fish was carried out during the period from June to October in 1982. They were collected by netting, fishing with rod and line, and using the bait of crushed oil cake in a transparent plastic bowls at the three localities, Daebon-dong, Kugil-dong, and Hoam-dong in the river Taechong, Kyungpook Province, Korea. Five species of fresh-water fish, the crussian carp, Carassius carassius Linnaeus, the bullhead, Coreobagrus brevicorpus Mori, the fat minnow, Moroco oxycephalus (Bleeker), the flat bitterling, Paracheilognathus rhombea(Temminck et Schlegel), and the catfish, Parasilurus asotus (Linnaeus), and two kinds of brackish-water fish, the grey mullet, Mugil cephalus (Linnaeus) and the sweetfish, Plecoglossus altivelis (Temminck et Schlegel) were examined. Four species of the metacercariae, Exorchis oviformis, Metacercari hasegawai, Metorchis orientalis and undetermined larvae were found. Of these, the encysted larvae of the human intestinal fluke, Metagonimus yokogawai, were found from three kinds of fresh-water fish, the crussian carp, the bullhead and the fat minnow and one species of brackish-water fish, the sweetfish and the infestation rates for the larvae varied appreciably from fish to fish. The intensity of infestation with the Metagonimus larvae in the three species of fresh-water fish as low, and the average number of the larvae per gram of flesh varied from 0.5 to 0.2. By comparison, the brackish-water fish was more heavily infested and the mean number of cysts per gram of flesh in Plecoglossus altivelis was 109.2. It was found that infection with Metagonimus yokogawai is caused by consuming raw fresh-water fish and brackish-water fish caught in the river Taechong, Kyungpook Province, Korea.
parasitology-helminth-trematoda ; Metagonimus yokogawai ; Carassius carassius ; Coreobagrus brevicorpus ; Moroco oxycephalus ; Paracheilognathus rhombea ; Parasilurus asotus ; Mugil cephalus ; Plecoglossus altivelis ; epidemiology ; metacercaria

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

A survey on soil samples collected from the vegetable gardens and vinyl houses in the vicinity of Taegu was conducted for the discovery of helminth eggs and larvae from October 1981 to September 1982. The samples collected were examined utilizing the "Commonly Employed" and Kamiya's techniques. The details of comparative features of larval nematodes are taken from the handbook of parasitology by Matsubasyhi et al. (1965). The results were compared with the data obtained from soil samples collected at the same area by Lee(1976). Five kinds of helminth eggs, ascarid, hookworm, liver fluke, Trichostrongylidae, and whipworm and undetermined eggs were found. Of these, the incidence of ascarid eggs was found to be the highest, 70.5 per cent, followed by whipworm and hookworm eggs, 9.9 and 9.2 per cent, respectively. The average number of ascarid eggs per 100 grams of soil was higher in the vinyl houses, compared with the number in the vegetable gardens than in the vinyl houses. By contrast, the number of hookworm eggs was relatively high in the vegetable gardens. In the monthly incidences of helminth eggs, ascarid eggs were found every month, continuing fairly high incidences all the year round. However, hookworm eggs was found for 8 months from February and September, with low monthly incidences between 4.0 and 22.2 per cent, and Trichostrongylidae eggs were found for 6 months from April to September, with lower incidences than those of hookworm. Three kinds of larval nematodes, the filariform and rhabditoid larvae of hookworm, Trichostrongylidae, and undetermined larvae were found in the soil of farms, but the incidences of larvae were quite low. The average number of larvae per 100 grams of soil was 0.05. When the number of eggs per 100 grams of the soil in 1976 were compared with 1982, pronounced reduction of the number was encountered in all helminth eggs. However, the incidences and the average number of larvae per 100 grams of the soil were so low that it was impossible to compare the data between 1976 and 1982.
parasitology-helminth-nematoda ; Ascarid ; hookworm ; Clonorchis sinensis ; Trichostrongylidae ; Trichuris trichiura ; epidemiology

The present study was undertaken to determine the pattern of infestation with the encysted larvae of digenetic trematodes in freshwater fish collected in both the natural and fish breeding ponds in Kyungpook Province, Korea. The fish collected in the two natural ponds, Nass-chil, and Sa-il, and three fish breeding ponds, Deok-dong, Mo-gok, and Seongryu-tunnel, were examined from July 1980 to August 1981. The data were compared with the results obtained from freshwater fish caught in the river Kumho by Hwang and Choi(1980). Ten species of fish caught in the ponds were examined for the presence of the larval trematodes. Seven species of the larvae, Clonorchis sinensis, Cyathocotyle orientalis, Echinochasmus species, Exorchis oviformis, Metacercaria hasegawai, Metagonimus yokogawai, and Metorchis orientails and two kinds of undetermined cyst A and B were found. The infestitation rate for Clonorchis sinensis metacercaria in the Korean shiner, Gnathopogon atromaculatus collected in the natural ponds was higher than the rate in the river Kumho by Hwang and Choi(1980), but lower in the fish collected in the breeding ponds. By contrast, the infestation rate in the flat bitterling, Paracheilognathus rhombea in ponds was higher, while there was no change of the rate in the southern top-mouthed minnow, Pseudorasbora parva. The intensity of infestation, expressed as the average number of Clonorchis sinensis metacercaria per gram of flesh, were lower than in the bullhead, Coreobagrus brevicorpus, and Gnathopogon atromaculatus in the ponds in 1981. The intensity was higher in Paracheilognathus rhombea, but no fluctuation in the intensity of infestation in Pseudorasbora parva was observed. The infestation rates and densities for the encysted larvae of digenetic trematodes except for Clonorchis sinensis varied from fish to fish. However, it was found that the rate and intensity of the larval trematodes from all the fish in the ponds was lower than from those in the rivers in Kyungpook Province, Korea.
parasitology-helminth-trematoda ; Clonorchis sinensis ; Cyathocotyle orientalis ; Echinochasmus species ; Exorchis oviformis ; Metacercaria hasegawai ; Metagonimus yokogawai ; Metorchis orientails ; Pseudorasbora parva ; Coreobagrus brevicorpus ; Gnathopogon atromaculatus ; Paracheilognathus rhombea ; Carassius carassius ; Coreoperca herzi ; Cyprinus carpio ; Lipomis macrochirus ; Moroco oxycephalus ; Zacco platypus ; epidemiology

School children between 6 to 12 years of age were studied for the presence of Entamoeba histolytica cysts in a period of 6 months, form March to August 1980. Fecal specimens collected form urban and rural children were examined first by the Lugol stained technique and then by the Faust's iron alum hematoxylin method. A total of 731 specimens were examined. Of these 26.9 per cent, 197 specimens, harbored the cysts. The demonstration rate for the cysts by age group varied from 19.6 to 43.5 per cent. The demonstration rate in boys was 24.4 per cent and in girls 29.8 per cent. Similarily, the rate in urban and rural area was 32.4 and 24.1 per cent, respectively. It was found in the present study that there were no significant differences in the age and sex rates of demonstration between urban and rural children but there was a predominance of the small race of Entamoeba histolytica over the large race.
parasitology-protozoa-Entamoeba histolytica ; entamoebiasis-epidemiology ; cyst

This survey was undertaken to determine the recent prevalence of lung fluke, Paragonimus westermani, in the three localities of Wiseong county, Kyungpook Province, Korea and to compare the prevalence among the residents in the same areas between 1924 and 1980. The three localities, Ku-seong, Sam-chun, and Um-ji villages (dong) have been known as the endemic areas of Paragonimus westermani. The surveys were made on the general population. They were examined using intradermal test with Paragonimus westermani antigen, and the diagnosis of paragonimiasis was made depending on the positive intradermal reaction. The sputum examination could not be performed beacause the residents were inaccessible. The prevalence of Paragonimus westermani among the residents in the three communities varied from 1.4 percent to 7.9 per cent, with an average of 4.0 per cent. Whereas, the average reported by Ichinomiya in 1924 was 4.7 percent. There are no significant differences in the sex and age specific rates of infection between 1924 and 1980. With the abundant density of Semisulcospira snails and crayfish in Sam-chun stream and the high rate of infection with Paragonimus westermani among the residents in the village, it is found that Sam-chun village, one of the three localitied in Wiseong county, where Ichinomiya (1924) surveyed, was still the endemic focus of Paragonimus westermani.
parasitology-helminth-trematoda ; Paragonimus westermani ; paragonimiasis ; epidemiology