• Parasites, Hosts and Diseases
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• 제58권3호
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• pp.257-265
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• 2020

The outbreak of human toxoplasmosis can be attributed to ingestion of food contaminated with Toxoplasma gondii. Toxoplasmosis recently increased in domestic and stray dogs and cats. It prompted studies on the zoonotic infectious diseases transmitted via these animals. Sero- and antigen prevalences of T. gondii in dogs and cats were surveyed using ELISA and PCR, and B1 gene phylogeny was analyzed in this study. Toxoplasmosis antibodies were measured on sera of 403 stray cats, 947 stray dogs, 909 domestic cats, and 2,412 domestic dogs collected at nationwide regions, Korea from 2017 to 2019. In addition, whole blood, feces, and tissue samples were also collected from stray cats (1,392), stray dogs (686), domestic cats (3,040), and domestic dogs (1,974), and T. gondii-specific B1 gene PCR was performed. Antibody prevalence of stray cats, stray dogs, domestic cats, and domestic dogs were 14.1%, 5.6%, 2.3%, and 0.04%, respectively. Antigen prevalence of these animals was 0.5%, 0.2%, 0.1%, and 0.4%, respectively. Stray cats revealed the highest infection rate of toxoplasmosis, followed by stray dogs, domestic cats, and domestic dogs. B1 gene positives were 5 of stray cats, and identified to high/moderate pathogenic Type I/III group. These findings enforce that preventive hygienic measure should be strengthened at One Health level in dogs and cats, domestic and stray, to minimize human toxoplasmosis infections.

• Asian Pacific Journal of Cancer Prevention
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• 제17권5호
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• pp.2565-2571
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• 2016

A cross-sectional survey was conducted among 730 participants from 4 rural districts of Nakhon Ratchasima province, Thailand, with a reported high incidence of liver fluke infection. This study was aimed to examine and evaluate the nutritional status in relation to Opisthorchis viverrini infection. Participants were purposive selected from Chum Phuang, Mueang Yang, Bua Yai, and Kaeng Sanam Nang districts. Stool samples were prepared by Kato Katz technique and then assessed by microscopy. Anthropometry was evaluated according to the body mass index from weight and height. Descriptive statistics and Spearman rank correlation coefficients were used to evaluate the association between the nutritional status and O. viverrini infection. Of 1.64% infected with O. viverrini the highest proportions were found in age groups ${\geq}61$ and 41-50 years old, Mueang Yang district. The majorities of participants had normal weight (32.2%), followed by class II obesity (28.1 %), class I obesity (21.8%), underweight (10.3%), and class III obesity (8.63%). Nutritional status with class II obesity (rS=0.639, p<0.01) and class I obesity (rS=0.582, p<0.05), had moderately statistical significant correlations with O. viverrini infection. Meanwhile, normal weight (rS=0.437, p<0.05) and class III obesity (rS=0.384, p<0.05) demonstrated lower statistical significance. These findings raise the possibility that infection with O. viverrini may contribute to fat deposition and thereby have long-term consequences on human health. Further studies are needed to better understand whether O. viverrini contributes directly to fat deposition and possible mechanisms.

• 한국환경보건학회지
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• 제2권1호
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• pp.1-4
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• 1975

The law prohibits use of human excreta without proper treatment since 1968 in Korea, but the rate of infection of parasitic diseases is high among all ages of people. An examination of parasitic eggs in soil and vegetables was performed from April to September, 1974, soil samples were collected near toilet, at gardens, at vegetable farms with excreta used and not used, and strawberry farms in Shindong myon, Chunseong-gun, Kangwon province, and vegetables collected were cabbage, young radish, lettuce, Welshonion, spinach and strawberry. Main findings are as follows 1. Positive samples of Ascaris lumbricoides are 18 out of 25(64%) in the soils near toilet, 9 out of 28(3.2%) in the garden soils and 8 out of 18(44%) in the soils of vegetable farms. 2. Trichocephalus trichiurus and Enterobius vermicularis were detected in 8 soil samples respectively Trichostrongylus orientalis 7(25%) and Ancylostoma duodenale 3(11%) out of in the soils near toilets. 3. Parasitic egg negatives are 62(55%) out of 112 soil samples. 4. Ascaris lumbricoides is found in 11 roots(48%) of cabbage and young radish out of 23 respectively, 14 lettuce(34%) out of 41,4 Welsh onion(40%) out of 10,3 spinach(33%) out of 9, and 2 strawberry(11%) out of 18. 5. Ancylostoma duodenale positives are 2 roots of cabbage(9%) out of 23, 4 young radish (17%) out of 23, and 7 lettuce(17%) out of 41, and negatives of parasitic eggs on vegetables are 62 roots(51%) out of 124 samples.

• Parasites, Hosts and Diseases
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• 제49권4호
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• pp.441-443
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• 2011

This survey was performed to investigate and compare egg positive rates (EPRs) of Enterobius vermicularis among preschool children in 3 Korean localities (Chuncheon-si, Inje-gun, and Paju-si) in 2008. A total of 7,048 preschool children were examined. Overall, the total EPR was 4.0%; the EPR was the highest in Chuncheon-si (5.6%), followed by Inje-gun (4.5%) and Paju-si (3.4%). The EPR of boys (4.9%) was higher than that of girls (3.1%). The EPR significantly increased with age, with the highest observed in 5~7-year-olds. These findings demonstrate that E. vermicularis infection is widely prevalent among preschool children in Chuncheon-si, Inje-gun, and Paju-si, Republic of Korea.

• Parasites, Hosts and Diseases
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• 제58권5호
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• pp.589-592
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• 2020

Cyclospora cayetanensis is an apicomplexan protozoan and is one of the most common pathogens causing chronic diarrhea worldwide. Eight stool samples with diarrheal symptom out of 18 Korean residents who traveled to Nepal were obtained, and examined for 25 enteropathogens including 16 bacterial species, 5 viral species, and 4 protozoans in stool samples as causative agents of water-borne and food-borne disease. Only C. cayetanensis was detected by nested PCR, and 3 PCR-positive samples were sequenced to confirm species identification. However, the oocysts of C. cayetanensis in fecal samples could not be detected by direct microscopy of the stained sample. As far as we know, this is the first report of a group infection with C. cayetanensis from a traveler visiting Nepal, and the second report of a traveler's diarrhea by C. cayetanensis imported in Korea.

• Parasites, Hosts and Diseases
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• 제59권3호
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• pp.257-263
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• 2021

Human gnathostomiasis is a parasitic disease caused by Gnathostoma nematode infection. A rapid, reliable, and practical immunoassay, named dot immuno-gold filtration assay (DIGFA), was developed to supporting clinical diagnosis of gnathostomiasis. The practical tool detected anti-Gnathostoma-specific IgG4 in human serum using crude extract of third-stage larvae as antigen. The result of the test was shown by anti-human IgG4 monoclonal antibody conjugated colloidal gold. The sensitivity and specificity of the test were both 100% for detection in human sera from patients with gnathostomiasis (13/13) and from healthy negative controls (50/50), respectively. Cross-reactivity with heterogonous serum samples from patients with other helminthiases ranged from 0 (trichinosis, paragonimiasis, clonorchiasis, schistosomiasis, and cysticercosis) to 25.0% (sparganosis), with an average of 6.3% (7/112). Moreover, specific IgG4 antibodies diminished at 6 months after treatment. This study showed that DIGFA for the detection of specific IgG4 in human sera could be a promising tool for the diagnosis of gnathostomiasis and useful for evaluating therapeutic effects.

• Parasites, Hosts and Diseases
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• 제52권6호
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• pp.691-694
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• 2014

The purpose of this study was to conduct a survey of Dirofilaria immitis infection among stray cats in Korea using nested PCR. We included 235 stray cats (121 females and 114 males) and evaluated each for the presence of feline heartworm infection. Blood samples were collected from 135 cats in Daejeon, 50 cats in Seoul, and 50 cats from Gyeonggi-do (Province). Of the 235 DNA samples, 14 (6.0%) were positive for D. immitis. The prevalence of infection in male cats (8/114, 7.0%) tended to be higher than that in female cats (6/121, 5.0%), but the difference was not statistically significant. In each location, 8, 2, and 4 cats were positive for infection, respectively, based on DNA testing. No significant differences in the prevalence were observed among the geographic regions, although the rate of infection was higher in Gyeonggi-do (8.0%) than Daejeon (5.9%) and Seoul (4.0%). We submitted 7 of the 14 D. immitis DNA-positive samples for sequencing analysis. All samples corresponded to partial D. immitis cytochrome c oxidase subunit I gene sequences with 99% homology to the D. immitis sequence deposited in GenBank (accession no. FN391553). To the best of our knowledge, this is the first survey using nested PCR to analyze the prevalence of D. immitis in stray cats in Korea.

• Parasites, Hosts and Diseases
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• 제51권6호
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• pp.621-627
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• 2013

Paragonimiasis is a food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Vietnam, research on Paragonimus and paragonimiasis has been conducted in northern and central regions of the country. Using a combination of morphological and molecular methods, 7 Paragonimus species, namely P. heterotremus, P. westermani, P. skrjabini, P. vietnamensis, P. proliferus, P. bangkokenis, and P. harinasutai, have been identified in Vietnam. Of these, the first 3, P. heterotremus, P. westermani, and P. skrjabini, are known to infect humans in other countries. However, in Vietnam, only P. heterotremus, found in some northern provinces, has been shown to infect humans. Even nowadays, local people in some northern provinces, such as Lai Chau and Yen Bai, are still suffering from P. heterotremus infection. In some provinces of central Vietnam, the prevalence and infection intensity of P. westermani metacercariae in freshwater crabs (the second intermediate hosts) are extremely high, but human cases have not been reported. Likewise, although P. skrjabini was found in Thanh Hoa Province, its pathogenicity to humans in Vietnam still remains uncertain. The results of molecular phylogenetic analyses of Vietnamese Paragonimus species provides new insights on the phylogeny and taxonomy of the genus Paragonimus. Comprehensive molecular epidemiological and geobiological studies on the genus in Vietnam and adjacent countries are needed to clarify the biodiversity and public health significance of the lung flukes.

• Parasites, Hosts and Diseases
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• 제24권2호
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• pp.209-212
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• 1986

The present study was undertaken to evaluate the present status of intestinal parasitic infection in Seoul area, Korea. During the period from June 1985 to July 1986, a total of 5,251 stool samples were collected in Department of Clinical Pathology, Hanyang University Hospital and examined by formalin-ether sedimentation technique once for helminth ova and protozoan cysts. The results were summarized as follows: 1. The overall egg positive rate of intestinal helminthes was 2.53%; and 1.43% for Clonorchis sinensis, 0.7% for Trichuris trichiura, 0.13% for Metagonimus yokogawai, 0.06% for hookworm, and 0.02% for Ascaris lumbricoides, Diphyllobothrium latum and Hymenolepis nana, respectively. 2. The overall cyst positive rate of intestinal protozoa was 1.07%. Cyst positive rate was 0.06% for Entamoeba histolytica and 0.13% for Giardia lamblia, respectively. 3. Higher prevalence of intestinal parasitic infection was observed in male and in $21{\sim}50$ year-old groups. 4. The highest prevalence of Clonorchis sinensis infection was observed in 40th age group (3.4%), and male (2.3%) was more infected than female (0.7%) in general.

• 응용통계연구
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• 제18권1호
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• pp.27-41
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• 2005

『전국 장내 기생충 감염실태조사』를 위해 새로운 표본설계를 하였다. 2000년 인구 주택총조사의 10% 표본조사자료를 조사모집단으로 사용하였고, 조사의 특성상 각종 기생충의 감염율이 아주 낮은 관계로 통상적인 분석방법 대신에 상대위험도과 오즈비를 사용하였다. 표본배정은 네이만 배정의 절충형을 사용하였다. 또한 전국 단위와 특성별 추정이 가능하도록 하였고 추정의 정확성을 측정하기 위해 추정량의 분산식을 유도하였다.