• Parasites, Hosts and Diseases
• /
• v.32 no.4
• /
• pp.223-230
• /
• 1994

Clonorchiasis is an important parasitic disease of humans in Korea. The present study intended to compare sonographic findings with histopathological changes in experimental clonorchiasis. Eighteen New Zealand white rabbits were infected with metacercariae of Cknorchis sinensis, and examined 4, 10, and 22 weeks post-infection (PI). Four infected rabbits were treated with praziquantel 10 weeks PI and were examined 12 weeks after treatment. Sonography revealed mild to severe dilatation of the intrahepatic ducts (IHDD) and slightly increased periductal echoes in 12 out of 14 rabbits at 4 weeks PI, and all of the animals after 10 and 22 weeks PI and 12 weeks after treatment. The histopathological lesions were duct dilatation, mucosal hyperplasia, and periductal fibrosis, which progressed from 4 weeks to 22 weeks PI and even in treated rabbits. The dilated intrahepatic ducts over 1 mm diameter were detected by sonography. The present results indicate that sonographic findings are well correlated with histopathological lesions in rabbit clonorchiasis except for early phase of light burden of infection. The sonography has a limitation in discriminating residual sequelae of the ducts after praziquantel treatment.

• Journal of agricultural medicine and community health
• /
• v.25 no.2
• /
• pp.441-448
• /
• 2000

This study was performed to investigate the prevalence and its related factors on the Clonorchis sinensis(C.S.) of inhabitants at Goksung-gun, Chollanam-do. After the population was stratified by gender, age, resident area, 651 residents living in eight villages were sampled by cluster sampling method. We interviewed the subjects to survey the various characteristics using the questionnaire, and examined stools to confirm the infection of C.S. from November to December, 1998. The prevalence of C.S. was 19.0%. The factors related with the infection of C.S. were male(adjusted odds ratio, of female=1.71, 95% confidence interval=1.07-2.72), 45-64 year old group(aOR of under 45 year old group=2.16. 95% CI=1.21-3.85), above 65 year old group(aOR of under 45 year old group=2.34, 95% CI=1.31-4.15), basin villagers(aOR of inland villagers=2.34, 95% CI=1.31-4.15), current drinker(aOR of nondrinker=1.83, 95% CI=1.12-2.98), those who took raw fish(aOR of persons who didn't it or take cooked fish=2.09, 95% CI=1.21-3.88) and persons who know the infection status(aQR of the persons who didn't know it=0.57, 95% CI=0.37-0.89). In conclusion, these results suggest that several life styles such as ingestion of raw fish, drinking habit. So we think that it is necessary to set up the efficient management programs for the treatment and prevention of C.S. infection.

• Parasites, Hosts and Diseases
• /
• v.52 no.2
• /
• pp.201-204
• /
• 2014

This study was undertaken to characterize the properties of a 100 kDa somatic antigen from Metagonimus yokogawai. Monoclonal antibodies (mAbs) were produced against this 100 kDa antigen, and their immunoreactivity was assessed by western blot analysis with patients' sera. The mAbs against the 100 kDa antigen commonly reacted with various kinds of trematode antigens, including intestinal (Gymnophalloides seoi), lung (Paragonimus westermani), and liver flukes (Clonorchis sinensis and Fasciola hepatica). However, this mAb showed no cross-reactions with other helminth parasites, including nematodes and cestodes. To determine the topographic distribution of the 100 kDa antigen in worm sections, indirect immunoperoxidase staining was performed. A strong positive reaction was observed in the tegumental and subtegumental layers of adult M. yokogawai and C. sinensis. The results showed that the 100 kDa somatic protein of M. yokogawai is a common antigen which recognizes a target epitope present over the tegumental layer of different trematode species.

• Parasites, Hosts and Diseases
• /
• v.21 no.2
• /
• pp.219-223
• /
• 1983

Echinostomatid eggs were found from a 21year old man, whose native village is Munkyong-gun, Kyongsangnam-do during fecal examination in October 1983. The eggs were detected again one week later concommitantly with the eggs of Clonorchis sinensis. He had no subjective symptoms related with these fluke infections. He was treated with praziquantel ($Distocide^{\circledR}$) 20 mg/kg in single dose and purgated with magnesium salt. One echinostomatid fluke and 4 adults of C. sinensis were collected from the diarrheal stools. After morphological observation, the echinostomatid fluke was identified as Echinostoma hortense Asada, 1926. This is the first record on human E. hortense infection in Korea.

• Parasites, Hosts and Diseases
• /
• v.37 no.2
• /
• pp.77-83
• /
• 1999

To ascertain residual sonographic and histopathological findings of clonorchiasis after treatment, the present study evaluated sonographic findings in rabbits which were infected with 500 metacercariae of C.sinensis every 6 months for 18 months after treatment with praziquantel. The sonographic findings were analyzed in terms of intrahepatic bile duct dilatation and periductal echogenicity, and histopathological findings were observed after the last sonographic examination. Compared with the sonographic findings before treatment, dilatation of the intrahepatic bile ducts became mild to some degree in four of the seven cases and increased periductal echogenicity resolved in four of them. The histopathological specimens after 18 months showed that periductal inflammation has almost resolved but moderate dilatation of the intrahepatic ducts and mucosal hyperplasia persisted. The periductal fibrosis minimally resolved. The log-lasting sonographic findings in cured clonorchiasis make sonography less specific.

• Parasites, Hosts and Diseases
• /
• v.45 no.2 s.142
• /
• pp.139-144
• /
• 2007

We investigated a small-scale serological survey to screen tissue-parasitic helminthiases of North Koreans as one of research programs for re-unification of Korea. Soil-transmitted helminthiases were found highly prevalent among North Korean residents at the border with China. ELISA using 4 tissue-parasitic helminth antigens was applied to 137 residents living in Cheongjin-shi, Hamgyeongbuk-do, North Korea and 133 female refugees in South Korea in 2004-2005. Among a total of 270 samples, 31 (11.5%), 25 (9.3%), and 11 (4.1%) were positive for specific IgG antibodies to antigens of Clonorchis sinensis, Taenia solium metacestode, and sparganum, respectively. The overall positive rate was 21.5%; 38.2% in males and 15.8% in females. The present finding suggests that tissue parasites, such as C. sinensis, T. solium metacestode and sparganum are highly prevalent in some limited areas of North Korea. These foodborne tissue-parasitic helminthiases should be considered for future control measures of parasitic diseases in North Korea.

• Parasites, Hosts and Diseases
• /
• v.27 no.3
• /
• pp.187-196
• /
• 1989

The effects of gamma irradiation on the survival and development of C. sinensis metacercariae were studied to evaluate the feasibility of irradiation as a control measure for clonorchiasis. Pseudorasbora parve were collected at an endemic river of clonorchiasis and were used for irradiation of the fluke in three schemes. The first (Scheme 1) was irradiation of the isolated metacercariae from the fish followed by infection to experimental rats. The second (Scheme 2) was irradiation of the fish, and then the metacercariae were isolated and in(ected to rats. The third (Scheme 3) was irradiation on the rat livers after infection with normal metacercariae. Irradiation doses varied from 5 to 100 Gy for Schemes 1 and 2, and 10 to 25 Gy for Scheme 3. The rats were sacrificed 2 to 6 weeks after infection. In Scheme 1, the metacercariae irradiated at 50 Gy failed to survive in the rats after 2 or 6 weeks. However, 1 to 44% of the metacercariae irradiated at 5∼30 Gy survived. The estimated LD50 of Scheme 1 was 16.5 Gy. The flukes irradiated in Scheme 2 survived better than those in Scheme 1. The average worm recovery rate in 50 Gy was 28%(7∼39% individually). Increasing the dose up to 100 Gy brought a remarkably low survival rate of an average 1%(0∼3% individually). The LD50 of Scheme 2 was 47.5 Gy. Worm recovery rates in the 10 Gy group of Scheme 3 were 21∼39%, and those in the 25 Gy group were 2% and 34%. Although the metacercariae were irradiated, all of the recovered worms were morphologically normal. Only the worms irradiated with 10 Gy or 25 Gy after 9 days from infection in Scheme 3 showed underdeveloped testes and seminal receptacle. The present results suggest that irradiation of the fish by 100 Gy could be adopted as a control measure for clonorchiasis.

• Parasites, Hosts and Diseases
• /
• v.56 no.4
• /
• pp.335-339
• /
• 2018

This study was conducted to investigate the prevalence of intestinal parasites among students from Goseonggun, Gangwon-do and Hadong-gun, Gyeongsangnam-do as typical low and high endemic counties. From May to July 2017, a total of 2,033 fecal samples were collected at 27 elementary, 10 junior high, and 8 high schools from 2 counties and examined by the Kato-Katz technique for egg-positive surveys (Collection rate: 37.02% [2,033/5,492]). Of the participants examined, 13 (0.64%) were found to harbor eggs of 3 parasitic species, Trichuris trichiura, Clonorchis sinensis and Metagonimus yokogawai. Based on the regional distribution, the egg-positive rate in Goseong-gun was 0% (0/550) and that in Hadong-gun was 0.88% (13/1,483). The positive rates for C. sinensis, M. yokogawai, and T. trichiura in Hadonggun were 0.20% (3/1,483), 0.61% (9/1,483), and 0.07% (1/1,483), respectively. The present survey showed that the prevalence of parasitic infection among students is currently very low even in remote, previously endemic areas, and the present status of parasitic diseases can be summarized as some transmission of fish/food-borne trematodes. Thus, it is necessary to carefully, continuously monitor the trematode infection status, particularly of C. sinensis and M. yokogawai.

• Parasites, Hosts and Diseases
• /
• v.57 no.3
• /
• pp.273-281
• /
• 2019

The infection status of digenetic trematode metacercariae (DTM) was investigated in fishes from 2 representative visiting sites of migratory birds in Gyeongsangnam-do, the Republic of Korea (Korea). A totaly 220 freshwater fishes (7 species) were collected from Junam-jeosuji (reservoir), and 127 fishes (7 species) were also collected from Woopo-neup (swamp) in June and October 2017. As the control group, total 312 fish (22 spp.) from Yangcheon in Sancheong-gun, Gyeongsangnam-do were also collected in June and October 2017. All fishes collected in 3 sites were examined with the artificial digestion method. In the fishes from Junam-jeosuji, more than 4 species, i.e., Clonorchis sinensis, Echinostoma spp., Diplostomum spp. and Cyathocotyle orientalis, of DTM were detected and their endemicy was very low, 0.70. More than 6 species, i.e., C. sinensis, Echinostoma spp., Metorchis orientalis, Clinostomum complanatum, Diplostomum spp. and C. orientalis, of DTM were found in the fishes from Woopo-neup, and their endemicy was low, 5.16. In the fishes from Yangcheon, more than 8 species, i.e., C. sinensis, Metagonimus spp., Centrocestus armatus, C. complanatum, C. orientalis, M. orientalis, Echinostoma spp., and Diplostomum spp., of DTM were detected, and their endemicity was relatively high, 95.48. The percentages of avian trematode metacercariae (ATM) were 99.6% and 94.7% in fishes from Junam-jeosuji and Woopo-neup whereas it was 74.1% in the control site, Yangcheon. The above findings suggested that migratory birds partly affect in endemicity of DTM in the fish in the 2 visiting sites in Gyeongsangnam-do, Korea.

• Parasites, Hosts and Diseases
• /
• v.34 no.2
• /
• pp.95-106
• /
• 1996

The infestation rates and abundances of human infecting metacercariae (Clonorchis sinensis, Metcgonimus spry. , Centrocestus crmatus, Echinostoma hortense, Echinochusnus japonicw, Clinostomum complanctum) in freshwater fish were investigated at the three river areas - Taewhagang (river), Hyongsangang (river), Nakdonggang (river) - in Kyongsang-do and at four streams - Yonpungchon, Munsanchon, Kyonganchon, and Konjiamchon- in Kyonggi-do, Korea in 1994-1995. The fish caught at Taewhagang were heavily infested with metacercariae of Clonorchis sinensis and Centrocestw armctus. At Hyongsangang, Zncco platypus and Z. temmincki were moderately infested with metacercariae of C. crmctus. Chomanpo, at the basin of Nakdonggang, was still endemic for C. sinensis. In the fish caught at four streams of Kyonggi-do, metacercariae of C. sinensis exhibited the highest infestation rate and intensity out of 6 species of metacercariae. The infestation intensity of C. sinensis metacercariae in fish flesh was markedly different according to each division of flesh. The cause of this difference was conjectured as a result of larval behavior. The metacercariae of C. omnt5 were found in almost all parts, except scales and fins, of fish. The infestation rates and intensities of C. sinensis and C. armntus metacercariae in Taewhagang greatly increased as compared with those of previous reports . RhinoBobius bmnneus and Aconthorhone5 macropterus are newly recorded intermediate hosts of Echinostonn hortense. The reason of large differences from previous data was discussed and the standard method of metacercaria examination was proposed.