1.PCR Detection and Molecular Characterization of Pentatrichomonas hominis from Feces of Dogs with Diarrhea in the Republic of Korea.
Yun Ah KIM ; Hye Youn KIM ; Shin Hyeong CHO ; Hyeong Il CHEUN ; Jae Ran YU ; Sang Eun LEE
The Korean Journal of Parasitology 2010;48(1):9-13
Pentatrichomonas hominis is considered a commensal protozoan in the large intestine of a number of mammalian hosts, such as cats, dogs, and non-human primates. The resulting infections, which can induce diarrhea, have been attributed to opportunistic overgrowth of P. hominis. This study was performed to confirm the P. hominis infection and its molecular characterization from the feces of puppies with diarrhea. Fecal samples were obtained from 14 German shepherd puppies with diarrhea over 1 week (7 females and 7 males, 2-9 months of age) residing on a dog farm in August 2007. Species-specific PCR assay identified P. hominis 18S rRNA genes in 3 of the 14 puppies (1 female and 2 males; 1 aged 2 months and 2 aged 9 months). This phylogenetic analysis established that P. hominis belonged to the 1st clade, which is comprised of Bos taurus and Felines.
Animals
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Base Sequence
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Cluster Analysis
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DNA, Protozoan/chemistry/genetics
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DNA, Ribosomal/chemistry/genetics
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Diarrhea/parasitology/*veterinary
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Dog Diseases/*parasitology
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Dogs
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Feces/*parasitology
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Female
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Genes, rRNA
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Male
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Molecular Sequence Data
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Phylogeny
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Polymerase Chain Reaction/methods
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Protozoan Infections, Animal/*parasitology
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RNA, Protozoan/genetics
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RNA, Ribosomal, 18S/genetics
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Republic of Korea
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Sequence Analysis, DNA
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Sequence Homology
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Trichomonadida/*classification/genetics/*isolation & purification
2.Seasonal Prevalence of Mosquitoes, Including Vectors of Brugian Filariasis, in Southern Islands of the Republic of Korea.
Hyeng Il CHEUN ; Shin Hyeong CHO ; Hee Il LEE ; E Hyun SHIN ; Jong Soo LEE ; Tong Soo KIM ; Won Ja LEE
The Korean Journal of Parasitology 2011;49(1):59-64
A survey of mosquitoes, including the vector status of Brugia malayi filariasis and their relative larval density, was conducted from 2002 to 2005 at several southern remote islands of Jeollanam-do (province), Gyeongsangnam-do, and Jeju-do, Korea, where filariasis was previously endemic. Overall, a total of 9 species belonging to 7 genera were collected. Ochlerotatus togoi (formerly known as Aedes togoi), Anopheles (Hyrcanus) group, and Culex pipiens were the predominant species captured at all areas. Oc. togoi larvae were most frequently collected at salinity levels <0.5% during June and July, with densities decreasing sharply during the rainy season in August. The most likely explanation for the eradication of filariasis in these areas is suggested to be an aggressive treatment program executed during the 1970s and the 1990s. However, high prevalence of the vector mosquitoes may constitute a potential risk for reemerging of brugian filariasis in these areas.
Animals
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Brugia malayi/parasitology
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Culicidae/*classification/growth & development/parasitology
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Humans
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Insect Vectors/*classification/growth & development/parasitology
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Population Density
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Prevalence
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Republic of Korea
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Seasons
3.PCR Diagnosis of Entamoeba histolytica Cysts in Stool Samples.
Joung Ho MOON ; Shin Hyeong CHO ; Jae Ran YU ; Won Ja LEE ; Hyeng Il CHEUN
The Korean Journal of Parasitology 2011;49(3):281-284
Amebiasis is a protozoan disease caused by Entamoeba histolytica and a potential health threat in areas where sanitation and hygiene are inappropriate. Highly sensitive PCR methods for detection of E. histolytica in clinical and environmental samples are extremely useful to control amebiasis and to promote public health. The present study compared several primer sets for small subunit (SSU) rDNA and histone genes of E. histolytica cysts. A 246 bp of the SSU rDNA gene of pure cysts contained in phosphate-buffered saline (PBS) and in stool samples was successfully amplified by nested PCR, using the 1,147-246 bp primer set, of the primary PCR products which were pre-amplified using the 1,147 bp primer as the template. The detection limit of the nested PCR using the 1,147-246 primer set was 10 cysts in both groups (PBS and stool samples). The PCR to detect histone gene showed negative results. We propose that the nested PCR technique to detect SSU rDNA can be used as a highly sensitive genetic method to detect E. histolytica cysts in stool samples.
DNA Primers/genetics
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DNA, Protozoan/genetics
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DNA, Ribosomal/genetics
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Entamoeba histolytica/genetics/*isolation & purification
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Entamoebiasis/*diagnosis
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Histones/genetics
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Humans
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Molecular Diagnostic Techniques/*methods
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Parasitology/*methods
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Polymerase Chain Reaction/*methods
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Protozoan Proteins/genetics
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Sensitivity and Specificity
4.Successful Control of Lymphatic Filariasis in the Republic of Korea.
Hyeng Il CHEUN ; Yoon KONG ; Shin Hyeong CHO ; Jong Soo LEE ; Jong Yil CHAI ; Joo Shil LEE ; Jong Koo LEE ; Tong Soo KIM
The Korean Journal of Parasitology 2009;47(4):323-335
A successful experience of lymphatic filariasis control in the Republic of Korea is briefly reviewed. Filariasis in the Republic of Korea was exclusively caused by infection with Brugia malayi. Over the past several decades from the 1950s to 2006, many investigators exerted their efforts to detection, treatment, and follow-up of filariasis patients in endemic areas, and to control filariasis. Mass, combined with selective, treatments with diethylcarbamazine to microfilaria positive persons had been made them free from microfilaremia and contributed to significant decrease of the microfilarial density in previously endemic areas. Significant decrease of microfilaria positive cases in an area influenced eventually to the endemicity of filariasis in the relevant locality. Together with remarkable economic growth followed by improvement of environmental and personal hygiene and living standards, the factors stated above have contributed to blocking the transmission cycle of B. malayi and led to disappearance of this mosquito-borne ancient disease in the Republic of Korea.
Animals
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Brugia malayi/isolation & purification
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Diethylcarbamazine/therapeutic use
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Elephantiasis, Filarial/diagnosis/*drug therapy/*epidemiology/parasitology
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Endemic Diseases
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Filaricides/therapeutic use
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Humans
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Republic of Korea/epidemiology
5.Prevalence of Clonorchiasis in Southern Endemic Areas of Korea in 2006.
Shin Hyeong CHO ; Ki Yeon LEE ; Byung Chul LEE ; Pyo Yun CHO ; Hyeong Il CHEUN ; Sung Tae HONG ; Woon Mok SOHN ; Tong Soo KIM
The Korean Journal of Parasitology 2008;46(3):133-137
This study was performed to investigate prevalence of clonorchiasis among the inhabitants living in villages along the 4 major rivers, Nakdong-gang (= river), Seomjin-gang, Youngsan-gang, and Guem-gang in southern Korea. From January to December 2006, a total of 24,075 stool samples (1 sample per an inhabitant) were collected in 23 localities and examined by the formalin-ether sedimentation technique. Of the inhabitants examined, 3,441 (14.3%) were found to harbor various types of intestinal parasite eggs, cysts or larvae. Numbers of infected people were 2,661 (11.1%) for Clonorchis sinensis, 431 (1.8%) for heterophyids, 226 (0.9%) for Entamoeba spp., 57 (0.2%) for Giardia lamblia, 30 (0.1%) for Trichuris trichiura, and 18 (0.07%) for echinostomes. Prevalence rates of clonorchiasis according to the river basin were 17.1% in Nakdong-gang, 11.2% in Seomjin-gang, 5.5% in Youngsan-gang and 4.6% in Guem-gang. Of the 2,661 C. sinensis egg-positive cases, 57.7% was male. The present findings suggest that clonorchiasis is still highly prevalent among inhabitants in the riverside areas of southern Korea, and it is necessary to implement a systematic control program in the endemic areas.
Adolescent
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Adult
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Age Distribution
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Aged
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Aged, 80 and over
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Animals
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Clonorchiasis/*epidemiology
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Clonorchis sinensis
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Endemic Diseases
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Feces/parasitology
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Female
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Humans
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Korea/epidemiology
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Male
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Middle Aged
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Parasite Egg Count
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Prevalence
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Rivers
6.Prevalence of Clonorchis sinensis Infection among Residents along 5 Major Rivers in the Republic of Korea.
Young Il JEONG ; Hee Eun SHIN ; Sang Eun LEE ; Hyeng Il CHEUN ; Jung Won JU ; Jung Yeon KIM ; Mi Yeoun PARK ; Shin Hyeong CHO
The Korean Journal of Parasitology 2016;54(2):215-219
Clonorchis sinensis is currently the most important parasite affecting public health problems in the Republic of Korea. We investigated the prevalence of C. sinensis infection among residents living along 5 major rivers in Korea. A total of 42,562 individual stool samples were collected from 37 localities and examined using the formalin-ether sedimentation technique. Helminth eggs were detected in 4,052 (9.5%) residents and 3,586 (8.4%) were infected with C. sinensis. The egg positive rate of C. sinensis in Nakdong, Seomjin, Geum, Yeongsan, and Han River was 11.7%, 9.9%, 6.5%, 3.1%, and 1.0%, respectively. The overall prevalence of clonorchiasis by sex was 11.2% in males and 6.2% in females. The age-prevalence was the highest in the 50-59 years band. It has been reconfirmed that the endemicity of clonorchiasis is higher in southern areas of Korea, especially along Nakdong and Seomjin Rivers. A combination of continuous control programs with health education initiatives is urgently required in these highly endemic areas of clonorchiasis in Korea.
Clonorchiasis
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Clonorchis sinensis*
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Eggs
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Female
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Geum
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Health Education
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Helminths
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Humans
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Korea
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Male
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Ovum
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Parasites
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Prevalence*
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Public Health
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Republic of Korea*
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Rivers*
7.Infection Status of Hospitalized Diarrheal Patients with Gastrointestinal Protozoa, Bacteria, and Viruses in the Republic of Korea.
Hyeng Il CHEUN ; Shin Hyeong CHO ; Jin Hee LEE ; Yi Young LIM ; Ji Hye JEON ; Jae Ran YU ; Tong Soo KIM ; Won Ja LEE ; Seung Hak CHO ; Deog Yong LEE ; Mi Seon PARK ; Hye Sook JEONG ; Doo Sung CHEN ; Yeong Mi JI ; Mi Hwa KWON
The Korean Journal of Parasitology 2010;48(2):113-120
To understand protozoan, viral, and bacterial infections in diarrheal patients, we analyzed positivity and mixed-infection status with 3 protozoans, 4 viruses, and 10 bacteria in hospitalized diarrheal patients during 2004-2006 in the Republic of Korea. A total of 76,652 stool samples were collected from 96 hospitals across the nation. The positivity for protozoa, viruses, and bacteria was 129, 1,759, and 1,797 per 10,000 persons, respectively. Especially, Cryptosporidium parvum was highly mixed-infected with rotavirus among pediatric diarrheal patients (29.5 per 100 C. parvum positive cases), and Entamoeba histolytica was mixed-infected with Clostridium perfringens (10.3 per 100 E. histolytica positive cases) in protozoan-diarrheal patients. Those infected with rotavirus and C. perfringens constituted relatively high proportions among mixed infection cases from January to April. The positivity for rotavirus among viral infection for those aged < or = 5 years was significantly higher, while C. perfringens among bacterial infection was higher for > or = 50 years. The information for association of viral and bacterial infections with enteropathogenic protozoa in diarrheal patients may contribute to improvement of care for diarrhea as well as development of control strategies for diarrheal diseases in Korea.
8.Follow-up Study of Patients Previously Diagnosed with Lymphatic Filariasis in Korea.
Hyeng Il CHEUN ; Hee Eun SHIN ; Da Won MA ; Sung Hee HONG ; Tae Yun KIM ; Sang Eun LEE ; JungWon JU ; Yun Kyu PARK ; Tong Soo KIM ; Shin Hyeong CHO
Osong Public Health and Research Perspectives 2017;8(6):421-424
OBJECTIVES: Korea was an endemic area for lymphatic filariasis (LF), caused by the nematode parasite Brugia malayi, until the 1970s. The World Health Organization recognized Korea as LF-free in June 2008. However, it is necessary to confirm that patients that have had LF in the past still test negative, to prevent the re-emergence of LF in Korea. METHODS: We followed up a total of 83 patients who had been diagnosed with LF between 2002 and 2010 in endemic LF areas. RESULTS: Fifty-two of the 83 subjects were negative for LF, whereas 31 subjects had re-located to a different city or province, were dead, or were unaccounted for. Most subjects with negative test results still exhibited edema in the legs or the arms, and some complained of redness and swelling in the legs or ankle joints. However, we found that these symptoms were due to diseases other than LF. CONCLUSION: In this follow-up study, we did not find any evidence indicating the potential re-emergence of LF in Korea.
Ankle Joint
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Arm
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Brugia malayi
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Edema
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Elephantiasis, Filarial*
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Follow-Up Studies*
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Humans
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Korea*
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Leg
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Parasites
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World Health Organization