• Parasites, Hosts and Diseases
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• 제45권2호
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• pp.121-128
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• 2007

Arthrostoma miyazakiense (Nematoda: Ancylostomatidae) is a hookworm species reported from the small intestines of raccoon dogs (Nyctereutes procyonoides) in Japan. Five Korean raccoon dogs (N. procyonoides koreensis) caught from 2002 to 2005 in Jeollanam-do (Province), a southeastern area of South Korea, contained helminth eggs belonging to 4 genera (roundworm, hookworm, whipworm, and Capillaria spp.) and cysts of Giardia sp. in their feces. Necropsy findings of 1 raccoon dog revealed a large number of adult hookworms in the duodenum. These hookworms were identified as Arthrostoma miyazakiense based on the 10 articulated plates observed in the buccal capsule and the presence of right-sided prevulval papillae. Eggs of A. miyazakiense were $60-65{\times}35-40{\mu}m$ (av, $62.5{\times}35{\mu}m$), and were morphologically indistinguishable from those of Ancyiostoma caninum. The eggs were cultured to infective 2nd stage larvae via charcoal culture, and 100 infective larvae were used to experimentally infect each of 3 mixed-bred puppies. All puppies harbored hookworm eggs in their feces on the 12th day after infection. This is the first report thus far concerning A. miyazakiense infections in raccoon dogs in Korea, and the first such report outside of Japan.

• Parasites, Hosts and Diseases
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• 제54권5호
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• pp.555-563
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• 2016

For several years, we have conducted a series of studies on the patterns of ancient parasitism prevailing in the soil of rural and urban areas of past Kingdom of Korea. Actually, during our survey of paleoparasitology in archaeological sites of Korean peninsula, numerous ancient parasite eggs were discovered in the samples from the city districts of Hansung (Joseon) and Buyeo (Baikje), the palace moat at Gyeongju (Silla), shell-midden site at Bonghwang-dong (Silla to Joseon), and the reservoir found in Hwawangsansung fortress (Silla). By the paleoparasitological studies, with respect to parasitism in the high-density populations of ancient towns and cities, we have managed to catch glimpses of the patterns prevalent therein: a serious parasitic contamination of the soil in ancient urban areas, but not in rural areas of the past. Our historical research also proposed the plausible mechanism of parasite infection very serious indeed among urban populations in Korean history. Although city dwelling doubtless has accrued significant benefits for people and populations with agriculture, it can be equally supposed that living in such highly populated areas might have facilitated the spread of parasite infection.

• Parasites, Hosts and Diseases
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• 제57권4호
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• pp.451-456
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• 2019

Adult specimens of Echinochasmus caninus n. comb. (Verma, 1935) (Trematoda: Echinostomatidae) (syn. Episthmium caninum Yamaguti, 1958) were recovered from 11 riparian people who resided along the Mekong River in Khammouane Province, Lao PDR. In fecal examinations done by the Kato-Katz technique, the cases revealed eggs of Opisthorchis viverrini/minute intestinal flukes, hookworms, and in 2 cases echinostome eggs. To recover the adult helminths, praziquantel 30-40 mg/kg and pyrantel pamoate 10-15 mg/kg in a single dose were given and purged with magnesium salts. Various species of trematodes (including O. viverrini and Haplorchis spp.), cestodes, and nematodes were recovered from their diarrheic stools. Among the trematodes, small echinostome flukes (n=42; av. 3.8 specimens per case) of 0.7-1.2 mm in length are subjected in this study. They are morphologically characterized by having 24 collar spines interrupted dorsally and anterior extension of vitellaria from the cirrus sac or genital pore level to the posterior end of the body. Particularly based on this extensive distribution of vitellaria, the specific diagnosis was made as Echinochasmus caninus. The cases were co-infected with various other helminth parasites; thus, clinical manifestations specific for this echinostome infection were difficult to determine. The present paper describes for the first time human E. caninus infections in Lao PDR. Our cases marked the 4-14th human infections with this echinostome around the world following the 3 previous cases reported from Thailand.

• Parasites, Hosts and Diseases
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• 제57권2호
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• pp.135-144
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• 2019

There have been some reports on schistosomiasis of school children in Sudan's Nile River basin area; however, information about the infection status of Schistosoma species and intestinal helminths among village residents of this area is very limited. Urine and stool samples were collected from the 1,138 residents of the Al Hidaib and Khour Ajwal villages of White Nile State, Sudan in 2014. The prevalence of overall schistosomiasis and intestinal helminthiasis was 36.3% and 7.7%, respectively. Egg positive rates were 35.6% for Schistosoma haematobium, 2.6% for S. mansoni, and 1.4% were mixed. The prevalence of schistosomiasis was significantly higher in men (45.6%) than in women (32.0%), in Khou Ajwal villagers (39.4%) than in Al Hidaib villagers (19.2%), and for age groups ${\leq}15$ years old (51.5%) than for age groups >15 years old (13.2%). The average number of eggs per 10 ml urine (EP10) of S. haematobium infections was 18.9, with 22.2 eggs in men vs 17.0 in women and 20.4 in Khou Ajwal villagers vs 8.1 in Al Hidaib villagers. In addition to S. mansoni eggs, 4 different species of intestinal helminths were found in the stool, including Hymenolepis nana (6.6%) and H. diminuta (1.0%). Collectively, urinary schistosomiasis is still prevalent among village residents in Sudan's White Nile River basin and was especially high in men, children ${\leq}15$ years, and in the village without a clean water system. H. nana was the most frequently detected intestinal helminths in the 2 villages.

• Parasites, Hosts and Diseases
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• 제59권2호
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• pp.167-171
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• 2021

Haemonchosis remains a significant problem in small ruminants. In this study, the assay of recombinase polymerase amplification (RPA) combined with the lateral flow strip (LFS-RPA) was established for the rapid detection of Haemonchus contortus in goat feces. The assay used primers and a probe targeting a specific sequence in the ITS-2 gene. We compared the performance of the LFS-RPA assay to a PCR assay. The LFS-RPA had a detection limit of 10 fg DNA, which was 10 times less compared to the lowest detection limit obtained by PCR. Out of 24 goat fecal samples, LFS-RPA assay detected H. contortus DNA with 95.8% sensitivity, compared to PCR, 79.1% sensitivity. LFS-RPA assay did not detect DNA from other related helminth species and demonstrated an adequate tolerance to inhibitors present in the goat feces. Taken together, our results suggest that LFS-RPA assay had a high diagnostic accuracy for the rapid detection of H. contortus and merits further evaluation.

• Parasites, Hosts and Diseases
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• 제60권3호
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• pp.187-193
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• 2022

The positive rate of Clonorchis sinensis is the highest among intestinal parasites in the Republic of Korea (Korea). More than 1.2 million people were at risk of C. sinensis infection in Korea in 2012. An intensive control program is being implemented for residents of the 5 major river basins to reduce helminthic infections, including C. sinensis infection. This study evaluated the continuous intensive control program for parasitic diseases including clonorchiasis in areas near the 5 major river basins in Korea over the past 10 years (2011-2020). A total of 335,020 fecal samples (one sample per resident) prepared by the modified sedimentation technic were microscopically examined. Those who expelled helminth eggs were treated with anthelmintics through local health centers and re-examined 3 months later. The overall positive rate of helminths egg was 7.1%. The annual positive rates were dramatically decreased from 14.4% (2011) to 5.9% (2020). The egg positive rate was highest in C. sinensis (5.3%), followed by heterophyid flukes (1.5%) and Trichuris trichiura (0.2%). The prevalence of C. sinensis was significantly higher in males (7.6%) than in females (3.7%), and the highest in the 50-59 years (7.0%) age group. Our results are beneficial to establish prevention and control policies against helminthiases including clonorchiasis in endemic areas in this country.

• Parasites, Hosts and Diseases
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• 제62권1호
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• pp.98-116
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• 2024

Epigenetic writers including DNA and histone lysine methyltransferases (DNMT and HKMT, respectively) play an initiative role in the differentiation and development of eukaryotic organisms through the spatiotemporal regulation of functional gene expressions. However, the epigenetic mechanisms have long been suspected in helminth parasites lacking the major DNA methyltransferases DNMT1 and DNMT3a/3b. Very little information on the evolutionary status of the epigenetic tools and their role in regulating chromosomal genes is currently available in the parasitic trematodes. We previously suggested the probable role of a DNMT2-like protein (CsDNMT2) as a genuine epigenetic writer in a trematode parasite Clonorchis sinensis. Here, we analyzed the phylogeny of HKMT subfamily members in the liver fluke and other platyhelminth species. The platyhelminth genomes examined conserved genes for the most of SET domain-containing HKMT and Disruptor of Telomeric Silencing 1 subfamilies, while some genes were expanded specifically in certain platyhelminth genomes. Related to the high gene dosages for HKMT activities covering differential but somewhat overlapping substrate specificities, variously methylated histones were recognized throughout the tissues/organs of C. sinensis adults. The temporal expressions of genes involved in eggshell formation were gradually decreased to their lowest levels proportionally to aging, whereas those of some epigenetic tool genes were re-boosted in the later adult stages of the parasite. Furthermore, these expression levels were significantly affected by treatment with DNMT and HKMT inhibitors. Our data strongly suggest that methylated histones are potent epigenetic markers that modulate the spatiotemporal expressions of C. sinensis genes, especially those involved in sexual reproduction.

• Parasites, Hosts and Diseases
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• 제21권1호
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• pp.105-110
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• 1983

대구시내의 비륭 시장에서 엽채류 등 상치 열무 및 배추를 구입하여 기생충란과 유충의 부착상을 1982연 7월부터 1983연 6월까지 1연간에 걸쳐서 조사하여 이(1969)와 최·이(1972)의 조사성적과 비교하였다. 율소엽은 단단한 솔로 세척하여 부착된 기생충의 종유, 부착률 및 채소 200g당 기생충란의 평균 부착수를 조사하였다. 채소엽에서 4종의 기생기란 회충, 모양선충, 구직및 간흡충란과 2종의 유충 기충의 사상 및 간상유충을 찾아 볼 수 있었다. 이 중 회충란의 부착률은 4.2%로서 가장 높았으며 다음은 구충란으로서 3.6%였다. 채소 2009당 회충란의 부착수는 열무 0.6f권, 상치 및 배추는 각각 0.3개였고 기충의 사상발충은 열무 0.4%, 상치 0.3개, 배추 0.1개였으며 간상유충은 열무 0.2%, 상치 0.1%, 배추 0.05개로서 간상유충보다 사상유충이 많이 부착되어 있었다. 이(1969)와 최·이(1972)의 조사성적에서는 채소 200g당 회충란의 부착수는 열무 7.5%, 상치 3.1%, 배추 0.5개였는데 비하여 이번 조사성속에서는 열무 0.6개, 상치 및 배추는 각각 0.3개로서 심히 감소되었음을 나타내었다.

• Parasites, Hosts and Diseases
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• 제55권4호
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• pp.439-444
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• 2017

The ability of nematodes to manipulate the immune system of their host towards a Th2 and T regulatory responses has been proposed to suppress the inflammatory response. Clinical trials have proposed a useful effect of helminth infections on improvement of inflammatory disorders. In this study, we investigated the immunomodulatory effect of Syphacia obvelata infection to induce intestinal tolerance in C57BL/6 mice. Mice were infected through the cagemates with self-infected BALB/c mice. Four weeks post-infection, expression levels of $IFN-{\gamma}$, $TNF-{\alpha}$, IL-17, and IL-10 were assessed in the supernatant of mesenteric lymph node (MLN) culture. $Foxp3^+Treg$ were measured in MLN cells by flow cytometry. In the S. obvelata-infected group, the percentage of Tregs ($5.2{\pm}0.4$) was significantly higher than the control ($3.6{\pm}0.5$) (P<0.05). The levels of IL-10 ($55.3{\pm}2.2$ vs $35.2{\pm}3.2$), IL-17 ($52.9{\pm}3.8$ vs $41{\pm}1.8$), $IFN-{\gamma}$ ($44.8{\pm}4.8$ vs $22.3{\pm}2.3$) and $TNF-{\alpha}$ ($71.1{\pm}5.8$ vs $60.1{\pm}3.3$) were significantly increased in infected mice compared to the control group (P<0.05). The above results showed the potential effects of S. obvelata to induce intestinal tolerance. Therefore, it seems that S. obvelata may increase the immunological suppressive function in the intestinal tract.

• Parasites, Hosts and Diseases
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• 제28권2호
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• pp.109-114
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• 1990

한국 가톨릭의사협회는 남미 에꽈돌국 과야스주의 해안 지방인 빨말 본당에서 운영하는 "빠띠마 성녀 기념 본당 진료소"의 의료사업을 지원하고 있다. 그 사업의 하나로 이 지역 메스띠조인의 보건 실태를 관찰하고 앞으로의 중점 보건 사업을 파악하기 의하여 1989년 8월 6일부터 8월 19일까지 주민 진료와 합께 대변검사를 실시하고 기생충 감염 실태를 조사하였다. 이 지역은 동부 태평양에 연한 해안 어촌 마을인 빨말(본당), 아양게, 함벨리(공소)와 해안에서 떨어져 있고 목축을 주업으로 하는 바빌 데세초, 리오세꼬, 밤빌꼬자오, 마난띠 알 데 꼴론체 및 세비자 등 공소마을로 구성되어 있고 주민은 모두 약 20,000명으로 추산된다. 대변검사는 직접 도말법(요드염색 후) 1매와 셀로판후층도말법 1매를 각각 검경하여 장내 원충 포낭 및 윤충 충란 배출을 검사하였다. 검사 대상자는 진료소를 찾은 주민이며 빨말 본당 지역의 주민 160명을 포함한 해안 마을 주민 226명과 내륙 공소 마을 주민 99명 등 모두 325명이었다. 대변검사 결과 충란 및 포낭 양성률이 66.1%이었고 윤충 충란 양성률은 38.2%, 원충 포낭 양성률은 56.1%이었다. 기생충별 양성률은 회충 18.1%, 편충 19.4%, 구충 0.6%, 왜소조충 3.7%, 유구 및 무구조충 1.8%, 이질아메바 19.4%, 대장아메바 28.6%, 소형아매바 5.5%, 요드아메바 1.5%, 람블편모충 11.1%, 킬로마스틱 스메니리 0.6%이었다. 이상의 결과를 종합하여 보면 이 지역에서 가장 중요한 기생충 감염은 이질 아메바와 람블편모충이며 따라서 위생적인 식수를 마련하는 것이 가장 중요한 보건사업이라고 판단되었다. 목축을 주로 하는 내륙 마을중에는 조충증과 유구낭미충증이 유행하는 지역이 있었다.