• Parasites, Hosts and Diseases
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• v.39 no.2
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• pp.85-118
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• 2001

Studies on Gymnophalloides seoi (Digenea: Gymnophallidae) and human infections are briefly reviewed. This minute intestinal fluke was first discovered from a Korean woman suffering from acute pancreatitis and gastrointestinal troubles. It was described as a new species by Lee, Chai and Hong in 1993. The southwestern coastal village where the patient resided was found to be a highly endemic area, and additional endemic areas have been identified. The parasite is very small, 0.33-0.50 mm long and 0.23-0.33 mm wide. and characterized by the presence of a ventral pit. The first intermediate host remains unknown, but the second intermediate host has been found to be the oyster Crassostrea gigas. Man and the Palearctic oystercatcher Haematopus ostralegus have been shown to be natural definitive hosts , and wading birds including the Dentish plover Charadrius alexandrinus are highly susceptible to experimental infection. Gerbils, hamsters, cats, and several strains of mice were also susceptible laboratory hosts. In experimentally infected mice, the parasites inhabit the small intestine, pinching and sucking the root of villi with their large oral suckers, but they did not invade beyond the mucosa in immunocompetent mice. However, they were found to invade the submucosa in immunosuppressed mice. Human G. seoi infections have been found in at least 25 localities; 23 islands on the Yellow Sea or the South Sea, and 2 western coastal villages. The highest Prevalence was found in a village on Aphaedo. Shinan-fun (49% e99 Positive rate) : other areas showed 0.8-25.3% prevalence. Infected people complained of variable degrees of gastrointestinal troubles and indigestion. The infection can be diagnosed by recovery of eggs in the feces; however, an expert is needed to identify the eggs. Praziquantel, 10mg/kg in single dose, is effective for treatment of human infections. Eating raw oysters in endemic areas should be avoided.

• Korean Journal of Veterinary Research
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• v.50 no.4
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• pp.273-277
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• 2010

The objective of this study was to investigate the infection rate of gastro-intestinal tract parasites on acquired laboratory nonhuman primates, Vervet monkey, Cynomolgus monkey, and Rhesus monkey acquired from Japan and China. These monkeys have been acclimating at an individual housing condition after our legal quarantine period. We examined 133 fecal samples to investigate parasitic infection using direct smear and formalin-ether-sedimentation technique. As a result, total parasitic infection rate was 33.8% (n = 45/133) for all monkeys. Two species of macaques, cynomolgus and rhesus, were infected with Trichuris trichiura (4), Giardia lamblia (4) and Balantidium coli (41). Vervet monkeys, which had been controlled by individual housing system for a long time, were clear for parasitic infection. The protozoan, Balantidium coli was one of the most frequently detected in these monkey colonies. Double infection was noted in only 4 monkeys and involved with Trichuris trichiura and Balantidium coli. Serious clinical symptoms were not observed in the most of the infected monkeys, but the monkeys infected by Giardia lamblia showed intermittent or chronic watery diarrhea. Consequently, the prophylactic anthelmintic treatment and periodic monitoring are essential to preserve the SPF colonies in the laboratory facility.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2006.11a
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• pp.7-16
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• 2006

Poultry products including meat and eggs constitute a major protein source in the American diet and disease - causing pathogens represent major challenges to the poultry industry. More than 95 % of pathogens enter the host through the mucosal surfaces of the respiratory, digestive and reproductive tracts and over the past few decades, the two main mechanisms used to control diseases have been the use of vaccines and antibiotics. However, in the poultry industry, there are mounting concerns over the ability of current vaccines to adequately protect against emerging hyper - virulent strains of pathogens and a lack of suitable, cost effective adjuvants. Thorough investigation of the immunogenetic responses involved in host-pathogen interactions will lead to the development of new and effective strategies for improving poultry health, food safety and the economic viability of the US poultry industry. In this paper, I describe the development of immunogenomic and proteomic tools to fundamentally determine and characterize the immunological mechanisms of the avian host to economically significant mucosal pathogens such as Eimeria. Recent completion of poultry genome sequencing and the development of several tissue-specific cDNA libraries in chickens are facilitating the rapid application of functional immunogenomics in the poultry disease research. Furthermore, research involving functional genomics, immunology and bioinformatics is providing novel insights into the processes of disease and immunity to microbial pathogens at mucosal surfaces. In this presentation, a new strategy of global gene expression using avian macrophage (AMM) to characterize the multiple pathways related to the variable immune responses of the host to Eimeria is described. This functional immunogenomics approach will increase current understanding of how mucosal immunity to infectious agents operates, and how it may be enhanced to enable the rational development of new and effective strategies against coccidiosis and other mucosal pathogens.

• Parasites, Hosts and Diseases
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• v.46 no.2
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• pp.77-82
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• 2008

Fishborne zoonotic metacercariae have not been reported from brackish water and marine fish from Vietnam waters although these parasites are common in the country's freshwater fish. Both wild-caught and cultured grouper (Epinephelus coioides and Epinephelus bleekeri), and mullet (Mugil cephalus) from brackish and marine waters located in Khanh Hoa province in central coastal Vietnam were examined, and found positive for zoonotic trematode metacercariae. From grouper, Heterophyopsis continua and Procerovum varium were recovered. The prevalence of H. continua ranged from 2.0 to 6.0% and that for P. varium ranged from 11.6 to 15.8%. Mullet were infected with Pygidiopsis summa and H. continua; both of these species are new records for Vietnam. The prevalence of P. summa in mullet was generally high, ranging from 17.6 to 75.5%, and was significantly higher than the prevalence of H. continua (2.5 to 32.4%). There were no significant differences in the prevalence of metacercariae between grouper from natural or cultured habitats, indicating that the highest risk of infection occurs in the wild-caught state prior to their placement in culture. Further, there was no difference in metacercarial prevalence between the 2 species of grouper. Infected wild-caught seed were only observed from January to October. Monthly variation in prevalence suggests seasonal variation in mullet infections occurs in this region with the highest transmission taking place from October to December. Basic investigations on the ecology and epidemiology of these intestinal flukes need to be carried out to determine their significance as a public health problem and the aspects of their biology that may be vulnerable to control interventions.

• Journal of fish pathology
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• v.15 no.3
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• pp.105-110
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• 2002

Thirty five catfish (Silurus asotus) cultured in a fish farm of Jungeup and 222 wild goby (Acanthoguobius flavimanus) caught from the estuary of Mankyoung River, Chonbuk province of Korea were examined the prevalence of myxosporidian infestation. A lot of white spherical myxosporidian cysts in the intestinal epithelium of catfish and the muscle of goby were easily found. The cysts in size were 56 × 73 (42-77 × 59-93 ㎜) in catfish and 2.43 × 0.95 ㎜ in goby. The infection rate (%) were 88.4 in catfish and 89.4 in goby. The Myxosporidians from the intestine of catfish and from the musculature of goby were identified as Myxoborus miyairii and Henneguya tridentigeri on the basis of the shape and structure of the spores under a light microscope. imensions (㎜) of fresh spores of Myxoborus miyairii: length, 11.0-12.0; width, 5.0-6.0; thickness, 3.5-4.0; polar capsule: length, 5.0-5.5; thickness, 1.5-2.0; polar filament: length, 40-45. Dimensions ($\mu{m}$) of fresh spore of Henneguya. tridentigeri: length, 10.0-12.0; width 6.0-8.0; thickness, 4.8; polar capsule: length, 4.6; thickness, 2.6; iodinophilic vacuole: 2.8 × 2.4. No significant pathological change was found from the infected fish. This is the first report on M. miyairii and H. tridentigeri from fish species in Korea.

• Journal of Microbiology and Biotechnology
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• v.27 no.8
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• pp.1401-1408
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• 2017

Petiveria alliacea L. (Phytolacaceae) is a medicinal plant with a broad range of traditional therapeutic properties, including the treatment of dysentery and intestinal infections caused by protozoan parasites. However, its effects against Entamoeba histolytica have not been reported yet. We investigated the antiamoebic activity present in the leaves of P. alliacea Antiamoebic activity was evaluated in methanolic and aqueous extracts, as well as in the hexanic, methanolic, and EtOAc fractions. The P. alliacea methanolic extract showed a better antiamoebic activity than the aqueous extract with an $IC_{50}=0.51mg/ml$. Likewise, the hexanic fraction was the most effective fraction, showing a dose-dependent activity against E. histolytica, with an $IC_{50}=0.68mg/ml$. Hexanic subfraction 12-19 showed the highest antiamoebic activity at 0.8 mg/ml, producing 74.3% growth inhibition without any toxicity in mammal cells. A major component in subfraction 12-19 was identified as isoarborinol, which produced 51.4% E. histolytica growth inhibition at 0.05 mg/ml without affecting mammal cells. The P. alliacea leaf extract has antiamoebic activity that can be attributed to a major metabolite known as isoarborinol.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.11
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• pp.4593-4596
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• 2015

Background: Opisthorchis viverrini (OV) infection is the main risk factor for cholangiocarcinoma and is often found in Northeastern Thailand. The prevalence of OV infection and the incidence of cholangiocarcinoma are major public health problems in this region. Objectives: The objectives of this study were to identify factors associated with OV infection among people in Nong Khai Province in order to develop a prevention programme in the community. Materials and Methods: The data were collected in July 2013. Stool specimens were examined for intestinal parasites within hours after collection using a normal saline wet preparation and the modified Kato-Katz technique. A case-control study was conducted to collect information about demographic data, the habit of eating unsafely prepared fish, the safe disposal of waste food, and the practice of defaecating in fields. Structured questionnaires were used to interview 351 participants (117 cases and 234 controls) in a random selection of 30 villages across Nong Khai Province. Multiple logistic regression was used to identify risk factors for OV infection. Results: In the multivariate analysis, the results showed that the factors which had a statistically significant association with OV infection were the habit of consuming unsafely prepared fish ($OR_{adj}=5.17$, 95%CI=2.49-10.74), the similar habit of family members ($OR_{adj}=3.25$, 95%CI=1.63-6.49), a history of O. viverrini infection ($OR_{adj}=5.64$, 95%CI=2.10-15.18), a history of taking praziquantel ($OR_{adj}=5.66$, 95%CI=3.11-10.29), and the unsafe disposal of waste food ($OR_{adj}=2.1$, 95%CI=1.10-3.80). Conclusions: The findings of this study highlight the features on which a community programme should focus in order to reduce the prevalence of opisthorchiasis and incidence of bile duct cancer.

• Parasites, Hosts and Diseases
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• v.54 no.4
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• pp.503-507
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• 2016

The genus Spirometra belongs to the family Diphyllobothriidae and order Pseudophyllidea, and includes intestinal parasites of cats and dogs. In this study, a plerocercoid labeled as Spirometra mansonoides from the USA was examined for species identification and phylogenetic analysis using 2 complete mitochondrial genes, cytochrome c oxidase I (cox1) and NADH dehydrogenase subunit 3 (nad3). The cox1 sequences (1,566 bp) of the plerocercoid specimen (USA) showed 99.2% similarity to the reference sequences of the plerocercoid of Korean Spirometra decipiens (GenBank no. KJ599679), and 99.1% similarity in regard to nad3 (346 bp). Phylogenetic tree topologies generated using 4 analytical methods were identical and showed high confidence levels with bootstrap values of 1.00, 100%, 100%, and 100% for Bayesian inference (BI), maximum-likelihood (ML), neighbor-joining (NJ), and maximum parsimony (MP) methods, respectively. Representatives of Diphyllobothrium and Spirometra species formed a monophyletic group, and the sister-genera status between these species was well supported. Trapezoic proglottids in the posterior 1/5 region of an adult worm obtained from an experimentally infected cat were morphologically examined. The outer uterine loop of the uterus coiling characteristically consisted of 2 complete turns. The results clearly indicated that the examined Spirometra specimen from the USA matched to S. decipiens very well, and indicated possible presence of the life cycle of this species in this region.

• Parasites, Hosts and Diseases
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• v.54 no.6
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• pp.703-710
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• 2016

The trichomonad species Tritrichomonas foetus and Pentatrichomonas hominis were recently detected in the feces of dogs with diarrhea. However, little information is available on the prevalence and pathogenicity of these parasites in the canine population. Therefore, the aim of this study was to determine the prevalence and molecular characterization of trichomonads infecting pet dogs in Anhui and Zhejiang provinces, east China. In total, 315 pet dogs, with or without diarrhea, from 7 pet hospitals were included in this epidemiological survey. Microscopy and PCR detected P. hominis in 19.7% (62/315) and 31.4% (99/315) of fecal samples, respectively. T. foetus infection was detected in 0% (0/315) of samples with microscopy and in 0.6% (2/315) with PCR. The prevalence of P. hominis was significantly higher in young dogs (${\leq}12months$) than in adult dogs (>12 months), and was significantly higher in diarrheic dogs (50.6%) than in non-diarrheic dogs (24.3%; P<0.05). Infection with T. foetus did not correlate with any risk factors evaluated in this study. A sequence analysis of the P. hominis PCR products showed minor allelic variations between our sequences and those of P. hominis strains from other hosts in different parts of the world. Type CC1 was the most common strain in dogs in east China. The internal transcribed spacer 1 (ITS1)-5.8S rRNA gene sequences from the 2 T. foetus isolates detected in this study displayed 100% identity and were homologous to the sequences of other strains isolated from domestic cats in other countries.

• Journal of Preventive Medicine and Public Health
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• v.51 no.2
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• pp.109-120
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• 2018

Objectives: This study aimed to investigate the current status of infectious disease research in North Korea by analyzing recent trends in medical journals from North Korea in comparison with research from South Korea. Methods: Three medical journals (Preventive Medicine, Basic Medicine, and Chosun Medicine) were analyzed from 2012 to 2016. Articles on tuberculosis (TB), malaria, and parasitic diseases were selected and classified by their subtopics and study areas. Two medical journals published in the South Korea were selected for a comparative analysis of research trends. Results: Of the 2792 articles that were reviewed, 93 were extracted from North Korea journals. TB research in North Korea was largely focused on multi-drug resistant TB and extrapulmonary TB, whereas research in South Korea more frequently investigated non-tuberculous mycobacteria. Research on parasitic diseases in North Korea was focused on protozoan and intestinal nematodes, while the corresponding South Korea research investigated various species of parasites. Additionally, the studies conducted in North Korea were more likely to investigate the application of traditional medicine to diagnosis and treatment than those conducted in South Korea. Conclusions: This study presents an analysis of research trends in preventive medicine in North Korea focusing on infectious diseases, in which clear differences were observed between South and North Korea. Trends in research topics suggest a high prevalence of certain parasitic diseases in North Korea that are no longer widespread in South Korea. The large proportion of studies examining traditional medicine implies a lack of affordable medicine in North Korea.