Publications by authors named "Hyeng Il Cheun"

Article Synopsis
  • * Researchers followed up on 83 patients diagnosed with LF from 2002 to 2010; 52 tested negative, while others were either untraceable or deceased.
  • * Symptoms like leg and arm edema observed in patients were linked to other diseases, indicating no evidence of LF's re-emergence in Korea.
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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.

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We investigated an October 2014 outbreak of illness caused by Shigella sonnei in a daycare center in the Republic of Korea (South Korea). The outbreak strain was resistant to extended-spectrum cephalosporins and fluoroquinolones and was traced to a child who had traveled to Vietnam. Improved hygiene and infection control practices are needed for prevention of shigellosis.

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Microsporidia are eukaryotic organisms that cause zoonosis and are major opportunistic pathogens in HIV-positive patients. However, there is increasing evidence that these organisms can also cause gastrointestinal and ocular infections in immunocompetent individuals. In Korea, there have been no reports on human infections with microsporidia to date.

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Objectives: This study aims to develop a high-sensitivity antibody diagnostic kit that will enable a rapid and accurate detection of Cryptospofidium parvum and Giardia lamblia in patients with diarrhea.

Methods: The cultivated C. parvum oocysts and G.

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Objectives: To identify the pathogen of the diarrhea outbreak in a village in Jeollabuk province in Korea in April 2010.

Methods: DNA extraction was performed from the 120 L of collected water, which was centrifuged at 10,000 x g for 30 min. PCR reactions were conducted in a total of 25 ul, which included PCR premix (GenDEPOT, Barker, TX, USA), 2 ul (∼100 ng) of extracted DNA, and 10 pmol of each primer.

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Objectives: Until the early 2000s, lymphatic filariasis would commonly break out in the coastal areas in Korea. Through steady efforts combining investigation and treatment, filariasis was officially declared eradicated in 2008. This study surveyed the density of vector species of filariasis in past endemic areas, and inspected filariasis DNA from collected mosquitoes for protection against the reemergence of filariasis.

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There are approximately 20 known species of the genus Cryptosporidium, and among these, 8 infect immunocompetent or immunocompromised humans. C. hominis and C.

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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.

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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.

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Objectives: The prevalence of Clonorchis sinensis infection was investigated among residents of the five major river basins, that is, Hangang, Nakdonggang, Seomjingang, Yeongsangang, and Geumgang River basins in Korea.

Methods: From January to December 2007, a total of 31,268 stool samples were collected from 29 localities and examined by the formalin-ether sedimentation technique.

Results: Intestinal parasite eggs and/or protozoan cysts were detected from 2957 (9.

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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.

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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.

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Cryptosporidiosis is a diarrheal illness caused by apicomplexa parasite Cryptosporidium spp. In this study, to examine the overall infection status of Cryptosporidium spp. in individuals residing in southern parts of Korea, eight counties around Yeongsan, Seomjin and Nakdong River valleys was surveyed.

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Clonorchis sinensis, the Chinese liver fluke, is the causative agent of clonorchiasis as well as liver and biliary diseases. The excretory-secretory products (ESPs) of the parasites play important roles in host-parasite interactions. In this study, we have investigated the proteome of ESPs obtained from C.

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Cryptosporidium parvum is an intracellular protozoan parasite that causes cryptosporidiosis in mammals. In this study, we identified a gene encoding mitochondrial iron-superoxide dismutase of C. parvum (Cp-mtSOD) and characterized biochemical properties of the recombinant protein.

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To investigate Cryptosporidium infection among healthy people, we collected stool samples from 150 healthy individuals in Gokseong, Muan, and Imshil Counties, southwest Korea, where neighbors on both an animal farm and a river respectively. In 12 of 150 samples, Cryptosporidium oocysts were detected by means of modified acid-fast staining. The bovine genotype, Cryptosporidium parvum, was identified by PCR/RFLP and 18S rRNA sequencing.

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We report on the first case of human babesiosis in Korea. The intraerythrocytic parasite (KO1) in the patient's blood mainly appeared as paired pyriforms and ring forms; but Maltese cross forms were not seen, and the parasite showed morphological features consistent with those of the genus Babesia sensu stricto. The sequence of the 18S rRNA gene of KO1 was closely related to that of Babesia spp.

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To establish the rapid detection method of airborne bacterial spores, we examined Bacillus anthracis spores by real-time PCR. One hundred liters of air were trapped on a filter of an air monitor device. After it was suspended in PBS, spores of B.

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Bacillus anthracis enters the body as an endospore, and encapsulation and toxin production occur after germination. Capsule is proposed to be an antiphagocytic factor, and toxin induces cytokine production for systemic shock. The dep gene, adjacent to the cap region for the encapsulation, degrades the high-molecular weight capsule (H-capsule) to the lower-molecular weight capsule (L-capsule), which releases into the culture supernatant.

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