The Hongcheon river system flows down through the Hongcheon area of Kangwon-do, and reaches to the Cheongpyeong Dam in Kyonggi-do. Stool specimens from the inhabitants residing along the Hongcheon river basin were examined to detect infection rate of Metagonimus sp., and the intermediate hosts were collected to detect larval stages. The results obtained were as follows: Thirty-nine (33 males and 6 females) out of 529 (314 males and 215 females) inhabitants were infected with Metagonimus sp., showing a total positive rate of 7.4 per cent. In eight areas surveyed, the specimens from Kulji-ri of Bukbang-myon at the middle part of the river showed the highest positive rate of 26.9 per cent (14 positives out of 52) (males; 38.2per cent). The specimens from Mogog-ri of Seo-myon at the downstream of the river showed a positive rate of 10.4 per cent (13 positives out of 125) (males;12.6 per cent). The positive rates in other regions were less than 10 per cent. The density of the first intermediate host, Semisulcospira sp., was the highest in Kulji-ri of Bukbang-myon (10-20 snails per m(2)), and the infection rate of Metagonimus cercariae in the snails was 10.7 per cent(13 positives out of 121 snails). The infection rate of Metagonimus metacercariae in Zacco platypus, the fresh water fish favorably eaten raw by the inhabitants, was 68.2 per cent (30 positives out of 44 fishes), and most metacercariae were detected under the scales (89.9 per cent). Adult flukes were obtained from the small intestine of a rat, 15 days after infection with the metacercariae obtained from Z. platypus. These adult flukes were identified to be the same srecies as those obtained from human hosts. By this survey, new endemic areas of Metagonimus infection were discovered along the Hongcheon river basin and the main source of infection was the fresh water fish, Z. platypus.
parasitology-helminth-termatoda ; Metagonimus sp. ; epidemiology ; metacercaria ; Zacco platypus

An epidemiological study on Metagonimus yokogawai infection was performed in Samcheok-gun, Kangwon province during the period from November 1983 to October 1984. Formalin-ether concentration technique and Stoll's dilution egg counting method were employed to figure out the prevalence and infection intensity of M. yokogawai infection. The results are summarized as follows: The prevalence of M. yokogawai infection was 13.3 percent among 1,172 examined ; 18.0 percent (114 out of 632) in male and 7.8 percent (42 out of 540) in female. The prevalence rates were different by stream; 15.5 percent in Ohsip-chon (stream), 11.8 percent in Maeup-chon and 1.6 percent in Gagok-chon. Along the basin of Oship-chon; 8.2 percent at the lower reaches in Samcheok-eup, 25.9 percent at the middle reaches in Miro-myon and 6.2 percent at the upper reaches in Dogeoe-eup, respectively. By age group, the highest rate (18.3-20.2 percent) was observed in 30-49 years of age (male : 24.1-28.7 percent, female 11.2-13.2 percent). By social strata, the positive rate was 15.0 percent (120 out of 799) in general inhabitants and 9.7 percent (36 out of 373) in school children. Intensity by EPG count in feces was 419 in average; the light infection (less than 400 EPG) was 70.4 percent, moderate infection (401-1,000 EPG) 19.4 percent and heavy infection (more than 1,001 EPG) 10.2 percent respectively. All the 67 sweetfish (length 10.3-18.5 cm) which were caught from Ohsip-stream were infected with metacercariae of M. yokogawai and the number of metacercariae detected were 382 per fish in average (323 in June and 382 in September). Experiences of intake of raw fresh-water fish [Plecoglossus altivelis and Leuciscus (Tribolodon) sp.] were present in 50.3 percent (354 out of 704) of the inhabitants along Ohsip-stream according to questionnaire study. The results of this survey indicated that the middle reaches of Ohsip-stream in Miro-myon, Samcheok-gun is the endemic region for M. yokogawai infection.
parasitology-helminth-trematoda ; Metagonimus yokogawai ; epidemiology ; metagonimiasis ; human ; Plecoglossus altivelis ; Leuciscus sp.

The prevalences of the fluke belonging to genus Metagonimus have been reported along the upper stream of inhabitants by several workers since 1980, however the taxonomical problems of the fluke was not yet settled. The larval flukes; cercaria and metacercaria as well as their intermediate hosts, and adult were studied in order to identify the Metagonimus in the areas. The results obtained are summarized as follows: The snails, Semisulcospira globus were collected from the three different localities along the upper stream of the River. The cercariae were found from 125(7.2%) out of 1,730 snails by natural emerging method, and were identified into 5 species including Metagonimus sp. (3.7%), Pseudexorchis major(1.4%), Cercaria nipponensis (0.9), Cercaria incerta (0.6%) and Cercaria yoshidae(0.6%). Cercariae of Metagonimus species had four to five oral spines on its anterior of the first line. The cercariae of Metagonimus were experimentally exposed to goldfish. Infection rate was 22.9% out of 105 goldfish, and the encysted metacercariae were found in fins(86.7%) and on scales (13.7%) of the fishes, but not in their muscle, head or visceral organs. Seven species of fish were caught in the Daecheong reservoir and the upper stream. Infestations with metacercaria of Metagonimus were found 100% in Opsariichtys bidens and the parasitized numbers of the metacercariae were observed from 250 to 2,400 per fish. In the upper stream, Zacco temmincki, Z. platypus and Pseudogobio esocinus were infected 100% with the metacercaria, on the other hand, the fishes caught in the reservoir showed the lower infestation rates, and a few metacercariae found in the fishes Carassius carassius and Cyprinus carpio in the reservoir and the stream. The majority of metacercariae was detected only on the scales of fishes. In order to know the infectivity and the distribution patterns in the intestine of hosts, rats and dogs were infected with the metacercariae obtained from O. bidens and Z. platypus. In addition the metacercariae obtained from Z. temmincki, P. esocinus and goldfish were given to the rats. The recovery rates of the worms in the small intestine of dogs were higher (63.3-65.8%) than those of the rats (3.5-31.6%). The flukes were found mostly in the middle and the lower part of small tntestine of the rats and the dogs, but no worm was collected in the upper part of the intestine of rats. The size of adult flukes varied by the hosts. In the adult flukes, oral sucker was smaller than ventral sucker, and the right and left testes were located diagonally, the uterine tubules circled around the upper left testis. The average egg size was 29.1 x 17.7 micro-meter. According to the above results, the flukes belonging to genus Metagonimus distributed along the Geum River was concluded to be identical with Miyata type of M. yokogawai as that Saito had proposed.
parasitology-helminth-trematoda ; Metagonimus sp. ; epidemiology ; cercaria ; metacercaria ; Zacco temmincki ; Zacco platypus ; Pseudogobio esocinus ; Opsariichtys bidens ; Carassius carassius ; Cyprinus carpio

Recent patterns of infection with digenetic larval trematodes in fresh-water and brackish-water fish were studied in three locations of the river Taewha during the period from April to October 1988, and compared with the data reported previously in the same river. Of 16 species of fish examined, the encysted larvae of Cyathocotyle orientalis were found most frequently from 9 species of fresh-water fish. The metacercariae of Echinochasmus sp., Metacercaria hasegawai and Metagonimus yokogawai were found 8 species, those of Clonorchis sinensis from 7 species, and Exorchis oviformis and Metorchis orientalis from 5 species of fish. The infection rates of fish with C. sinensis metacercariae were not lower than those reported in 1980, wheres their intensity of infection was found lowered in 3 species, Coreobagrus brevicorpus, Gnathopogon atromaculatus, and Puntungia herzi. The infection rates of 3 species of fish with M. yokogawai metacercariae were lower than the results in 1982, while the rate was higher in 2 species, Zacco platypus, and Z. temmincki, and rather stationary in Plecoglossus altivelis. The intensity of infection in several species of fish appeared rather higher than in 1980. the encysted larvae of C. orientalis, Echinochasmus sp., E. oviformis and Metacercaria hasegawai showed variations in infection rates of fish in 1980 and in the present study. It was found that the rate of infection with digenetic larval trematodes in fresh-water fish was still relatively high in the river Taewha, and the metacercarial burden in the fish varied greatly by different fish in 1980 and in the present study.
parasitology-helminth-trematoda ; Cyathocotyle orientalis ; Echinochasmus sp. ; Metacercaria hasegawai ; Metagonimus yokogawai ; Clonorchis sinensis ; Exorchis oviformis ; Metorchis orientalis ; Coreobagrus brevicorpus ; Gnathopogon atromaculatus ; Puntungia herzi ; Zacco platypus ; Z. temmincki

This study was undertaken to evaluate the present status of intestinal helminthic infections in Koreans, from April 1967 through May 1969. The nationwidely collected stool specimens and scotch-tape anal swabs from primary schoolchildren, middle school students, draftees to army recruitment camp, soldiers and inhabitants of various parts of Korea were examined. The methods employed were Kato's cellophane thick smear technique and formalin-ether sedimentation technique in 40,581 for the prevalence rate of various intestinal helminths, scotch-tape anal swab technique in 8,585 for the prevalence rate of Enterobius vermicularis and by Stoll's dilution egg counting technique in 1,174 for the evaluation of the worm burden of some helminths. The results are as follows. Result of stool examination: The positive rate of intesinal helminthes of any kind was 90.5% among 40,581. In rural people, it was 92.3% in average in contrast to 85.0% in Seoul inhabitants. The infection rate of A. lumbricoides in 40,581 was 58.2%. It was higher in rural people 62.9% than in Seoul inhabitants and highest in 5-9 year-old group by age. The infection of Trichocephalus trichiurus showed the highest prevalence rate in Koreans and it was 74.5%. No remarkable difference was observed between Seoul inhabitants(72.2%) and rural people(75.2%). The tendency of higher prevalence rate with the older age group was observed. The infection rates of hookworm and Trichostrongylus orientalis in 40,581 examinations by cellophane thick smear were 5.1% and 5.8% respectively. But in 4,949 examinations for which refined cellophane thick smear technique and formalin-ether sedimentation technique were employed, the infection rates were turned out 17.6% in hookworm and 15.9% in T. orientalis. Although rural people showed higher infection rate of hookworm(18.8%) than Seoul inhabitants(13.8%), the reverse was true in T. orientalis infection rate(14.5% : 20.3%). Both kinds of infections were tend to be higher with the increase of age. The infection rates of Clonorchis sinensis and Metagonimus yokogawai were 4.7% and 0.4% respectively. In both kinds of infections male showed higher infection rates than female and the tendencies of higher infection rate in the older age group were observed. The provinces which showed the higher infection rate of C. sinensis were South and North Kyongsang Do and North Cholla Do, all of which are provinces of southern part of Korea. Some endemic foci of M. yokogawai were noticed in South Kyongsang Do and South Cholla Do. The infection rate of Taenia spp. by applying only the stool examination was 0.7% throughout the survey. No sex difference in infection rate of Taenia spp. was noticed, but in older age group it was increased. Cheju Do, the island of extreme southern part of Korea seemed the most endemic area and South and North Cholla Do were next in ranking of Taenia infection rate. The ova of Hymenolepis nana were observed in 0.2% and all of them were under the age of 20 except only one caes. The infection rate seemed higher in female (0.3%: 0.1%). No geographical difference was noticed except 1.1% of schoolchilderen and students of Cheju Do. Result of Scotch-tape anal swab technique for E. vermicularis infection. The infection rate of E. vermicularis in 8,585 urban and rural schoolchildren and rural inhabitants was 46.6%. Female (57.9%) had definitely higher infection rate than male (41.4%). The infection rate was significantly higher in rural people than Seoul schoolchildren. The exteme example was 79.7% in schoolchildren of South Cholla Do. Result of worm burden examination by Stoll's dilution egg-counting technique: Among 1,174 examinations, countable(E.P.G.> 100) cases of A. lumbricoides were 745(63.5%) and the mean E.P.G. was 9,723. The mean E.P.G. in Seoul inhabitants was 5,835 in contrast to 10,820 in rural people. The age group of 5-9 showed the heaviest mean E.P.G., 11,337. 70.6% of 745 cases were less than 10,000 in E.P.G. which means light infection. Countable cases by Stoll's technique for T. trichiurus ova were 63.5% and mean E.P.G. was 649. No difference between Seoul and rural inhabitants was observed. Grade I and II in which E.P.G. is less than 5,000 involve 99.3% of positive cases. 91 cases (7.9%) in 1,174 were positive for hookworm ova by Stoll's technique and mean E.P.G. was 501. All cases were in Grade I and II which were less than 5,000 in E.P.G. Trichostrongylus orientalis was positive only in 25 cases (2.1%) by Stoll's technique and mean E.P.G. was 340. No cases were found to have more than 5,000 in T. orientalis E.P.G. The mean E.P.G. of Clonorchis sinensis among the referred cases of clonorchiasis to Department of Parasitology, Seoul National University, was 9,416. On the other hand mean E.P.G. of C. sinensis was 21,376 among cases in the hyperendemic area of Kimhae, South Kyongsang Do, and 3,073 in cases from other various localities. Among referred clonorchiasis cases to our Department, 21.6% were turned out to have the E.P.G. more than 10,000. The cases who have the E.P.G. more than 10,000 in hyperendemic area, Kimhae were 40.7% and in other various localities were 9.1%
parasitology-helminth-nematoda-trematoda-cestoda ; epidemiology ; Ascaris lumbricoides ; Trichocephalus trichiurus ; Trichostrongylus orientalis ; Clonorchis sinensis ; Metagonimus yokogawai ; Taenia sp. ; Hymenolepis nana ; Enterobius vermicularis

This study was conducted to evaluate prevalence of intestinal helminthic infections and skin tests and Paragonimus and Clonorchis in tuberculosis(TB) patients in Korea. Stool examinations by formalin-ether technique and intradermal tests were carried out in 2 areas; Masan TB hospital and Kong-Ju TB hospital. The positive rate of intestinal helminths of any kind was 51.7 percent among 329 patients in Masan hospital, but 18.1 percent among 215 patients in Kong-Ju hospital. The infection rates of Trichocephalus trichiurus and Clonorchis sinensis were 20.7 percent and 17.6 percent respectively in Masan hospital patients, but the infection rates of T. trichiurus and C. sinensis were 6.5 percent and 6.0 percent respectively in Kong-Ju hospital patients. In skin tests, positive reactions to Paragonimus and Clonorchis antigens were 22.0 percent and 37.6 percent respectively in Masan hospital patients. On the contrary, Kong-Ju hospital patients showed the positive rates of 15.2 percent for Paragonimus and 27.2 percent for Clonorchis respectively.
parasitology-helminth-trematoda ; Ascaris lumbricoides ; Trichuris trichiura ; hookworm ; Trichostrongylus orientalis ; Clonorchis sinensis ; Paragonimus westermani ; Metagonimus yokogawai ; Taenis sp. ; Hymneolepis nana ; epidemiology ; skin test

The author reported in the previous pager on his observation of sudden death of Clonorchis sinensis cercaria before penetration into the body of fry such as Cyprinus carpio and Carassius auratus. And in these studies, the reason behind the fact was investigated and it was found that the mucous substances on the surface of a certain fishes have a strong wormicidal effect to the larva of C. sinensis. When cercariae of C. sinensis were immersed into the mucous substance of gold fish for three minutes 36 seconds to 4 minutes 20 seconds, into that of Aplocheilus latipes for 4 minutes 30 seconds to 5 minutes 20 seconds, into that of Cyprinus carpio for 5 minutes 15 seconds to 6 minutes l6 seconds, and into that of Carassius auratus for 5 minutes 20 seconds to 7 minutes 30 seconds, it was observed that they were all killed. No wormicidal effect against C. sinensis could be observed with the mucous substance obtained from Pseudorasbora parva, Misgurnus anguillicaudatus and Ophicephalus argus. No wormicidal effect against Metagonimus sp. cercaria is observed with the mucous substance obtained from Cyprinus carpio, Carassius auratus. The wormicidal effect of the mucous substances obtained from gold fish was destroyed when heated over 60 C. The movements of metacercaria of C. sinensis stopped after 10 minutes application of the mucous substance obtained from Cyprinus carpio and they were killed within 30 minutes. When the adult worms collected from the bile duct of experimentally infected rabbits for 20 to 60 days, were immersed into mucous substance from Cyprinus carpio, they were killed between 25 minutes and 35 minutes. No wormicidal effect could be observed with the mucous substance obtained from dead Cyprinus carpio, Carassius auratus, gold fish, when applied to the adult worms and larvae of C. sinensis.
parasitology-helmith-trematoda-Clonorchis sinensis, Metagonimus sp. ; Cyprinus carpio ; Carassius auratus ; Aplocheilus latipes ; Pseudorasbora parva ; Misgurnus anguillicaudatus ; Ophicephalus argus ; gold fish ; mucous substance

The authors examined 3,169 fecal specimens from inhabitants of seven localities such as City, Eups and Myons in Cheju Do on July 1970 with cellophane thick smear technique. The results were analysed and summarized as follows: The overall egg positive rate of helminths was 82.2% and it was attributed to high rates of soil-transmitted helminths as in case of other parts in Korea. The infection rates of each species were; A. lumbricoides 44.3%, T. trichiurus 65.6%, hookworm 1.5%, T. orientalis 0.8%, C. sinensis 0.2%, P. westermani 0.4%, M. yokogawai 0.9%, Taenia sp. 12.7% and H. nana 1.4%. The infection rates of soil-transmitted helminths were relatively lower than those of mainland Korea especially in case of hookworm and T. orientalis. The proportion of unfertilized ova passers among the Ascaris infected case was 22.1%. The ova of heterophyids, most probably Metagonimus yokogawai were detected in lower percentage but discovered throughout the localities surveyed and in all age groups. It is certainly presumed that Metagonimus infection is autochthonous. The most interesting results were obtained in Taenia sp. infection and the higher rates were shown in rural area than in urbanized areas. The positive rates were within 5% in childhood and adolescence but abruptly increased up to 36.4 % in adults.
parasitology-helminth-nematoda-trematoda-cestoda ; Ascaris lumbricoides ; Trichuris trichiura ; hookworm ; Trichostrongylus orientalis ; Clonorchis sinensis ; Paragonimus westermani ; Metagonimus yokogawai ; Taenia sp. ; Hymenolepis nana

Helminthic zoonoses are of significant importance to the public health and to the socioeconomic consequences especially in lost-meat, animal products and animal labor. For past several decades in Korea, it has been recognized that endoparasitic infections among domestic animals are extremely common and many of the helminth parasites of man have been acquired from, or are shared with domestic animals. However, there was no survey of a nationwide scale on the prevalence of animal helminthiasis; and control measures are also not satisfactory. Furthermore, because of the remarkable increase in the demand, number of domestic animals and pets is rapidly increasing in these days. Therefore, an extensive study on zoonotic helminths was carried out from July 1980 throughout August 1981 to understand the present status and parasite-host relationship from the epidemiological viewpoont. A total of 13,685 fecal specimens of cattles, sheeps, pigs, dogs and cats was collected from 26 localities in the country. The specimens were examined by formalin-ether centrifugal sedimentation technique. The results are summarized as follows: Of 13,685 specimens examined, 9,808(71.7 percent) were positive for helminth parasites. The positive rates were 99.0 percent in cattles, 86.5 percent on sheeps, 85.4 percent in pigs, 35.4 percent in dogs, 15.1 percent in cats. Single infection showed the highest rate (60.0 percent), and double infection(27.5 percent), triple(8.1 percent), quadruple(2.8 percent), quintuple(1.5 percent) and hexad(0.1 percent) were in decreasing order. In the present study, 18 species zoonotic helminths were found: 11 nematodes, 6 trematodes and 1 cestode. According to province, Cheju revealed the highest rate 84.8 percent, then Kyungnam 77.5 percent, Jeonnam 75.6 percent, Jeonpuk 75.4 percent, Kyonggi 75.2 percent, Chungnam 71.7 percent, Chungpuk 70.6 percent and Kangwon 64.2 percent were in decreasing order and Busan and Seoul showed 70.4 percent and 58.1 percent, respectively. Rural area showed slightly higher rate (74.7 percent) than urban area (68.5 percent), and rates of mountainous area (70.4 percent) and plain area (71.1 percent) are very similar. According to animal, helminths species and positive rates appeared in: Cattles: 6 nematodes and 3 trematodes; Strongyles 26.4 percent, Neoascaris vitulorum 24.1 percent, Trichuris ovis 12.0 percent, Nematodirus sp. 6.3 percent, Srongyloides papillosus 5.1 percent, Capillaria bovis 0.02 percent, Paramphistomum sp. 41.5 percent, Fasciola hepatica 33.2 percent and Eurytrema pancreaticum 29.7 percent. Sheeps: 3 nematodes and 2 trematodes: Strongyles 33.0 percent, S. papillosus 26.9 percent, Nematodirus sp. 14.6 percent, F. hepatica 31.7 percent and E. pancreaticum 19.6 percent. Pigs: 5 nematodes and 2 trematodes: Strongyles 43.1 percent, Ascaris suum 29.0 percent, Metastrongylus apri 20.3 percent, Trichuris suis 14.0 percent, Strongyloides ransomi 12.1 percent, Clonorchis sinensis 1.4 percent and Paragonimus westermani 0.9 percent, Dogs: 4 nematodes and 3 trematodes and 1 cestode: Toxocara canis 14.4 percent, Trichuris vulpis 9.5 percent, Ancylostoma caninum 8.0 percent, Toxascaris leonina 4.0 percent, C. sinensis 2.4 percent, Metagonimus yokogawai 1.3 percent, P. westermani 0.8 percent and Spirometra sp. 0.9 percent, Cats: 2 nematodes, and 3 trematodes and 1 cestode: Toxocara cati 7.7 percent, Ancylostoma tubaeforme 3.1 percent, C. sinensis 1.9 percent, P. westermani 1.4 percent, M. yokogawai 1.2 percent and Spirometra sp. 0.7 percent.
parasitology-helminth-nematoda-trematoda-cestoda ; cattle ; sheep ; pig ; dog ; cat ; epidemiology ; zoonosis ; Fasciola hepatica ; Eurytrema pancreaticum ; Paramphsitomum sp. ; Neoascaris vitulorum ; Trichuris ovis ; Strongyloides papillosus ; Nematodirus sp. ; Capillaria bovis ; Clonorchis sinensis ; Paragonimus westermani ; Ascaris suum ; Trichuris suis ; Strongyloides ransomi ; Metastrongylus apri ; Spirometra sp. ; Metagonimus yokogawai ; Toxocara canis ; Toxocara leonina ; Ancylostoma caninum ; Trichuris vulpis ; Ancylostoma tubaeforme ; Strongyles

A survey on the prevalence of intestinal parasites was performed during the period from April to June of 1969, to evaluate the present status of parasitic infections in ROK Army soldiers. Stool specimens of 1,0l2 soldiers were collected from a camp located in Won-Ju area, and examined by the method of formalin-ether sedimentation technique. For protozoan cysts, examined slide was stained with Lugol's iodine solution and for eggs of Enterobius, the Graham's scotch cellulose tape anal swab technique was applied. The results obtained in this survey were as follows: Of the 1,012 soldiers examined, 95.0 percent were found infected by one or more intestinal parasites and 28.7 percent were found positive for protozoan cysts. The positive rates of each parasites were; A. lumbricoides 61.0 percent, T. trichiurus 73.4 percent, hookworm 17.5 percent, T. orientalis 9.5 percent, E. vermicularis 0.1 percent (from stool specimen), C. sinensis 8.8 percent, M. yokogawai 1.1 percent, Taenia sp. 1.0 percent (from stool), H. nana 0.3 percent and E. histolytica 7.4 percent. E. coli 12.6 percent, E. nana 5.9 percent, I. buetchlii 0.7 pecent, G. lamblia 6.1 percent, and C. mesnili 0.8 percent. From the anal swabs, eggs of Enterobius were recovered in 2.6 percent, and eggs of Taenia sp. showed positive rate of 1.5 percent.
parasitology-helminth-trematoda-nematoda-cestoda-protozoa ; epidemiology ; Ascaris lumbricoides ; Trichuris trichiurus ; hookworm ; Trichostrogylus orientalis ; Enterobius vermicularis ; Clonorchis sinensis ; Metagonimus yokogawai ; Taenia sp. ; Hymenolepis nana ; Entamoeba histolytica ; Entamoeba coli ; Endolimax nana ; Iodamoeba buetchlii ; Giardia lamblia ; Chilomastix mesnili