• Parasites, Hosts and Diseases
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• v.57 no.5
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• pp.537-541
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• 2019

Toxoplasma gondii infection induces parasite infiltration and apoptosis in the spleen. However, dose-dependent parasite infiltration, apoptosis, body weight alternations and survival in mice remain largely unknown. In this study, mice were intraperitoneally infected with 10, 30 or 100 tachyzoites of T. gondii, respectively. Parasite infiltration and apoptosis in the spleen were analyzed on days 3, 7, and 9 post-infection by immunohistochemistry and flow cytometry. Significantly higher levels of T. gondii infiltration and apoptosis in the spleen were found in 30 and 100 tachyzoites infected mice compared to 10 tachyzoites infected mice on days 7 and 9 post-infection. Although 30 and 100 tachyzoites infected mice showed significant body weight loss compared to 10 tachyzoites infected mice, all of the 100, 30, and 10 tachyzoites infected mice died by days 12, 15, and 17, each respectively. Interestingly, T. gondii infiltration in 10 tachyzoites infected mice were limited to capsule area of the spleen on day 9 post-infection. Several areas of parasite infiltrations were found in the 30 tachyzoites infected mice, where noticeable levels of splenic capsule de-adhesion occurred. These results indicated that parasite infiltration and apoptosis in the spleen, as well as body weight loss (survival) are closely correlated with infection dosage. The level of T. gondii infiltration and apoptosis in the spleen and splenic de-adhesion were dependent on the parasite dose.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.567-577
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• 2020

The infection of marine diatom Coscinodiscus wailesii by a parasitic protist from the Yongho Bay of Busan, Korea was observed during the diatom bloom events in 2017 through 2018. The morphological and molecular features suggested that the parasitic nanoflagellate Pirsonia diadema was responsible for the infection. During the study period, the parasite prevalence ranged from 0.3% to 3.3%, and infected C. wailesii cells were observed only at surface seawater temperatures ranging between 10.9 and 19.9℃, although the host population appeared at temperatures above 25℃. The parasite and host system was successfully established as cultures. Using the cultures, we determined the morphological features over the infection cycle, parasite generation time, parasite prevalence as a function of inoculum size, and zoospore infectivity and survival time. The diatom C. wailesii was readily infected by the parasite P. diadema, with a parasite prevalence reaching up to 100% and a zoospore to host inoculum ratio above 20:1. The survival and infectivity of the parasite zoospores decreased with age. While the zoospores could survive up to 88 hours, they quickly lost their ability to infect after 48 hours. These results could lead to a better understanding of the biology and ecology of the parasitoid infecting the giant-sized diatoms in coastal waters.

• Korean Journal of Veterinary Service
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• v.22 no.1
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• pp.71-77
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• 1999

Research results on actual management situation of 16 goat farms and internal parasite infection of 155 goats from January to November in 1997 in southern Kyoungnam area were as follows ; 1. An average number of goats was 93. Among them, 81% were farming the goat as avocation with the income rate less then 50%, Eight-four percent of farms terminated the parasites more than twice a year, and the survey showed the black goats had a high digestive and respiratory disease infection rate. 2. The internal parasite infection rate of the black goat was 96.8% , the goats were infected with 13 types of parasites. Of them, Emeria sp was 87.1%, Ostertagia sp 55.5%, Paraphistanum sp 45.8%, and Moniezia expansa 20%, respectively. 3. On the survey of multiple infection rate, both double and triple infection were 19.4%, more than septuple-infection 15,5%, single infection 13.4%, quintuple infection 12.3 n, sextuple infection 9.0% and quadruple infection 7.7%, respectively. 4. Look over on seasonal infection rate, higher in fall and lower in winter. Especially, Paramishitom sp was higher in summer and winter, both Moniezia expansan and Bonaostom sp were higher in summer. 5. Research on the infection rate of parasites termination period revealed less-than-1-month period had 10-30 infection rate, the infection rate has increased sharply since 3 months passed after the goats were treated with parasite-cid.

• Journal of Environmental Health Sciences
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• v.3 no.1
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• pp.22-26
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• 1976

Korea Parasite Eradication Association alleged in its seasonal spring report in 1975 that 36.8 percent of primary, middle and high school students in Seoul area are infected with parasites. Such a high rate of infection is a result of having used raw excrement for manure. Soil is, therefore, to a large extent infected with parasite eggs. In order to present helpful reference materials for preventing parasite infection in the area where human feces have been used for manure, soil in Seoul area and the suburban districts is sampled at random and then the rate of infection in various areas and the variation of infection rate in the same area are studied. The results are as follows 1) The parasite infection rates the according to districts are, Sootaik-ri 39.9%, Chamsil-dong14.2%, Songpa-dong 13.2%, Sageun-dong 12.8% Chayang-dong 11.4%, Sungsoo-dong 8.5%. The above figures show that the rate becomes higher as the area is farther from the urban and residential districts and nearer to the rural area. 2) The rates of detected parasites according to their kinds are as follows Ascaridae 55.9%, Ancylostomatidae 19.9%, Trichocephalus 13.5%, Trichostrongylus 5.7%, Tenia 3.9%, Enterobius 1.1% 3) The monthly variation of infection rate in the same districts, in the case of Sageun-dong, is, August 25.7%, July 18.9%, June 16.2%, September 15.3% April 12.6%, May 11.3%. The above shows that the infection rate of soil is comparatively higher in the summer season.

• Parasites, Hosts and Diseases
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• v.61 no.1
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• pp.89-93
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• 2023

Parasite infection rates estimated by examining ancient coprolites can provide insights into parasitism in Joseon society. Using newly discovered Joseon period cases is essential to regularly update the parasite infection rates and reinforce the reliability of our previous estimations. In the present study, we investigated parasite infections in Joseon coprolites newly isolated from the cities of Euijeongbu, Gumi, and Wonju. We then updated the overall parasite infection rates of Joseon period samples (n= 30) as follows: 86.7% (26/30) for Trichuris trichiura, 56.7% (17/30) for Ascaris lumbricoides, 30.0% (9/30) for Clonorchis sinensis, and 30.0% (9/30) for Paragonimus westermani. The parasite infection rates in the Joseon society, estimated through coprolite examination, were very similar to those determined previously despite the addition of new cases to the existing data pool.

• Journal of Naturopathy
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• v.11 no.2
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• pp.136-142
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• 2022

Background: We are necessarily considering changes in the parasite infection rate and methods in Korea from 1970 to the present from the perspective of natural healing. Purposes: This study was to investigate how the difference in the rate of reduction in infection rate has changed and progressed to the present. Methods: A literature review was conducted. Results: Until the 1970s, Korea had one of the highest parasite infection rates. The Parasitic Disease Prevention Act was enacted to control the infection rate in 1966. From 1969, the nationwide national parasite management project was conducted for all students twice a year to treat all parasitic eggs until 1995. In addition, the government commissioned the Korean Association for Parasite Eradication (KAPE) to conduct a national parasite infection survey eight times, from 1971 to 2012, every two years. As a result, the overall egg positive rate of parasite was 84.3% in 1971 but decreased to 2.6% in 2012. In addition, Ascaris lumbricoides, Paragonimus westermani, Taenia spp., and intestinal protozoa were significantly reduced nationwide. Conclusions: Successful control in Korea is judged to have achieved a successful effect by systematically managing national economic growth, social consensus on parasite eradication, improved professional parasite prevention guidelines, and supply of effective anthelminthics.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.413-418
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• 2003

This survey of endoparasite infections among stray cats in Korea has been carried out during November 1995 to October 1997. A total of 215 stray cats were collected from SeoulㆍGyeonggi (54), Gangwon (38), Chungchong (34), Jeonla (38), and Gyeoungsang (51) areas. The positive rate of endoparasites was 184 (85.6%) cats among 215. Of isolated parasites, nematodes were the most often detected parasites especially Toxocara cati (102 cats), Ancylostoma tubaeformae (9 cats). The next most often detected parasites were cestodes (60/215; 27.9%) sepecially Spirometra erinaecei (34 cats), Taenia taeniaformis (26 cats). Opisthorchis tenuicollis was found in bile duct (9 cats) and Isospora spp. were identified in 41 cats (19.1 %). In mixed parasite infection, the rate of infections of nematodes, trematodes and protozoas was 3.3%, nematodes and cestodes with 8.8%, nematodes and protozoa with 4.2%, cestodes and protozoa with 1.9%. In parasitic infection by a considering age category, age from 2 to 4 years had the highest infection (92.3%), 1-2 years were 87.6%, over 4 years was 80.0%. 79.6 percents of the stray cats in SeoulㆍKyounggi areas were ranked the 1st in parasite infection. The next was Kyoungsang 76.5%, Kangwon 65.8%, Cholla 63.2% and Chungchong 61.8% in order. Considering age categories from birth to greater than 4 years, parasite infections were most prevalent in cats 2 to 4 years old; other ages seemed to have no effect on prevalence of parasitism. Also sex seemed to have no effect on prevalence of parasitism. In endoparasite infection, nematode and cestode infections were most frequently found, trematode infections were low, coccidiosis was showed very often.

• Parasites, Hosts and Diseases
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• v.51 no.3
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• pp.357-361
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• 2013

Several epidemiological surveys have reported the prevalence of Toxoplasma gondii infection in stray cats in Korea, but little information is available on T. gondii infection in household cats. The aim of the present study was to assess the prevalence and risk factors of T. gondii infection among household cats reared in Seoul, Korea. A total of 474 blood samples were collected from clinically healthy household cats. All samples were tested using ELISA and PCR. The risk factor analysis was based on a questionnaire filled out by the owners. The overall positive rate for ELISA and PCR assays was 2.2% (10/437) and 2.1% (10/474), respectively. With regard to the origin of cats, the positive rates among cats adopted from the animal shelter and veterinary clinic for stray cats were significantly different (P<0.05). Our study demonstrated that the positive rate of T. gondii infection in household cats was low and that this low prevalence was assumed to be associated with keeping the cats indoors and restriction of eating raw food and uncooked meat. Therefore, we suggest that the owners check the origin of the cats prior to adoption to prevent infection of other animals, including humans.

• The Korean Journal of Malacology
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• v.21 no.1
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• pp.33-40
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• 2005

Occurrence and prevalence of Marteilioides chungmueasis have been reported in several waters around Tongyeong but no report has been made for Pukman bay. Therefore, we investigated that the prevalence and infection intensities in Pukman Bay at the inside and the outside areas which are hydrographically divided by tidal current. Furthermore, various environmental parameters were investigated in order to elucidate effective parameter for parasitic infection. Infection rates of Marteilioides chungmuensis in adult oysters were ranged 3.3-20.0% at the inside area during September 2002 through January 2003, and 3.3-30.9% at the outside area during August 2002 through January 2003. External manifestation of infected oyster consisted of abnormal egg masses with nodular appearance in the soft tissue. Histopathological symptoms included massive hemocytic infiltration within or around the follicle wall and atrophic epithelium of digestive diverticula. For the environmental parameters, comparative study made differences between two side of the Bay during the infection period: inside > outside for SS while inside < outside for chlorophyll-a. A positive relationship was observed between chlorophyll-a and infection period, which might indicate the difference in food availability between two areas. The prevalence of ovarian parasite Marteilioides chungmuensis, therefore, was highly associated with food availability. Pearson's correlation analysis was made between environmental parameters and infection prevalence. Significance was observed in water temperature (p < 0.05), suspended solids (p < 0.01) and chlorophyll-a (p < 0.05). A principle component analysis showed that infection of the ovarian parasite, Marteilioides chungmuensis, exhibited effects of seasonality (component I = 55.2%) and chemical/physical environmental factors (component II = 24.4%). These results clearly indicate that the infection of ovarian parasite, M. chungmuensis in the Pacific oyster Crassostrea gigas is closely associated with seasonality and food availability.

• Journal of Environmental Health Sciences
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• v.3 no.1
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• pp.17-21
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• 1976

Korea Parasite Eradication Association alleged in its seasonal report spring/1975 that 36.8 percent of primary, middle and high school students in Seoul area are infected with parasites. For the purpose of a comparative study between the high rate of parasite infection among Korean students and that of parasite eggs attached to vegetables which perform intermediary role in carrying the eggs to human body, such vegetables as lettuce, Korean cabbage, young radish, green onion, cabbage which are on sale at several markets in Seoul city are sampled at random for study. The infection rate of parasitic eggs and larvae on vegetables is studied twice while the detaching mean while removing rate of eggs and larvae in proportion to the number of washing them is studied three times. Every 300 grams of vegetables is taken at random for examination and every one of them is washed with a hard brush and then the kinds of parasite eggs and the ratio of eggs attached to them are studied.