• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.37-42
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• 2017

Getah virus (GETV) infection causes sporadic outbreaks of mild febrile illness in horses and reproductive failure in pigs. In this study, we established a reverse transcription polymerase chain reaction (RT-PCR) method to detect GETV from suspected virus-infected samples. The reaction conditions were optimized and validated by using RNA extracted from GETV propagated in cell culture. A GETV-specific GED4 primer set was designed and used to amplify a 177 bp DNA fragment from a highly conserved region of the E1 glycoprotein gene in the GETV genome. RT-PCR performed with this primer set revealed high sensitivity and specificity. In the sensitivity test, the GED4 primer set detected GETV RNA at the level of $10^{2.0}\;TCID_{50}/mL$. In the specificity test, the GED4 primer set amplified only a single band of PCR product on the GETV RNA template, without non-specific amplification, and exhibited no cross-reactivity with other viral RNAs. These results suggest that this newly established RT-PCR method is useful for accurate identification of GETV infection in animals.

• Journal of Preventive Medicine and Public Health
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• v.49 no.1
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• pp.1-17
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• 2016

The Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak in South Korea in 2015 has drawn public attention regarding the legal regulation of infectious disease control in Korea. This paper discusses the interpretive and legislative concerns regarding the Infectious Disease Prevention and Control Act, its ordinance and enforcement regulations, as well as public statements from the relevant administrative agency. Future improvements are also proposed.

• Journal of Life Science
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• v.22 no.6
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• pp.794-798
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• 2012

Paratuberculosis (Johne's disease), a chronic wasting disease caused by Mycobacterium avium subspecies paratuberculosis (MAP), is a major cause of economic loss in the cattle industry. In Korea, national monitoring of breeding stock for MAP has been implemented. In this study, we report the results of serological testing to determine the prevalence of MAP in breeding stock of Korean native and dairy cattle during 2008 and 2009. A total of 3,927 serum samples were submitted (3,692 Korean native cattle and 235 dairy cattle) to Animal Disease Diagnostic Division, Animal, Plant and Fisheries Quarantine and Inspection Agency. The samples were classified into four different age groups for MAP; group 1 (${\leq}2$ year, n = 1,509), group 2 (>2 years to ${\leq}3$ years, n = 486), group 3 (>3 years to ${\leq}4$ years, n = 441), and group 4 (>4 years, n = 1,491). Overall seroprevalence of MAP in this study was 0.5% (21/3,927), which was much lower than that of conventional cattle (1.2-16.4%) in Korea. Also, the seroprevalence was determined by age groups: three of group 1 (0.2%), two of group 2 (0.4%), three of group 3 (0.7%), and 13 of group 4 (0.9%) were seropositive for MAP, respectively. Although seropositive samples were found in all age groups, the seroprevalence tended to increase with age. Our study showed that the seroprevalence of MAP in pure-bred breeding dairy cattle (0%) was lower than that in pure-bred breeding Korean native cattle (0.6%).

• Korean Journal of Veterinary Service
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• v.41 no.3
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• pp.203-210
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• 2018

Pasteurella multocida is an opportunistic organism that plays a significant role in porcine respiratory disease complex (PRDC). In the current study, we provide nationwide information of P. multocida isolates from pneumonic lungs of slaughter pigs by determining their prevalence, subspecies, biovars, capsular types, virulence-associated genes, and minimum inhibitory concentrations. P. multocida was the second most frequently confirmed (19.2%) bacterial pathogen and most of the isolates (88.9%) showed simultaneous infection with other respiratory pathogens, especially Mycoplasma hyopneumoniae (63.3%, P<0.001) and porcine circovirus type 2 (53.3%, P=0.0205). Of 42 isolates investigated, 41 (97.6%) were identified as P. multocida subspecies multocida, and only one isolate was identified as subspecies septica (biovar 5). All the isolates were capsular type A and the most prevalent biovar was biovar 3 (40.5%), followed by biovar 2 (31.0%). Comparing virulence-associated genes and biovars, all biovar 2 isolates exhibited $hgbB^-pfhA^+$ (P<0.001); all biovar 3 (P=0.0002) and biovar 13 (P=0.0063) isolates presented $hgbB^+pfhA^-$. Additionally, all biovar 2 (P=0.0037) isolates and most of biovar 3 (P=0.0265) isolates harbored tadD. P. multocida showed the highest resistance levels to oxytetracycline (73.8%), followed by florfenicol (11.9%). Continuous monitoring is required for surveillance of the antimicrobial resistance and new emerging strains of P. multocida in slaughter lines.

• Korean Journal of Veterinary Service
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• v.46 no.1
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• pp.35-45
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• 2023

Pathogenic Escherichia coli is the cause of a wide range of diseases in pigs, including diarrhea, edema disease, and septicemia. Diarrhea caused E. coli may result in significant economic losses, making pathogenic E. coli an important pathogen for the swine industry. This study investigated the prevalence of virulence factor genes, antimicrobial resistance phenotypes, and resistance genes in E. coli isolated from feces of piglets in Korea between 2017 and 2020. As a result, 119 pathogenic E. coli isolates were obtained from 601 fecal samples. The F4 adhesin gene and the STb enterotoxin gene were commonly present in E. coli isolated from diarrhea samples. The dominant virulotypes of isolates from diarrhea samples were STb, Stx2e, and F4:LT:STb. More than 80% of the screened isolates were resistant to ampicillin, sulfisoxazole, chloramphenicol, or tetracycline. To confirm the resistance mechanisms for β-lactam or quinolone, we investigated the genotypic factors of resistance. Each of the ceftiofur-resistant E. coli produced an extended-spectrum β-lactamase encoded by bla_CTX-M-14, bla_CTX-M-27, and bla_CTX-M-55. And all ciprofloxacin-resistant E. coli harbored mutations in quinoloneresistance-determining-regions. In addition, some of the ciprofloxacin-resistant E. coli contained the plasmid-mediated-quinolone-resistance genes such as qepA, qnrB1, or qnrD. This study has confirmed that the F4 fimbria and the STb enterotoxin are the most predominant in pathogenic E. coli isolated from piglets with diarrhea in Korea and there is a great need for responsible and prudent use of antimicrobials to treat colibacillosis.

• Korean Journal of Veterinary Research
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• v.63 no.4
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• pp.37.1-37.7
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• 2023

Canine respiratory coronavirus (CRCoV) is a significant pathogen that causes respiratory diseases in dogs, collectively known as a canine infectious respiratory disease. The virus is highly contagious and exhibits high seroprevalence worldwide. Currently, bovine coronavirus (BCoV) enzyme-linked immunosorbent assay (ELISA) kits are used to detect CRCoV antibodies. However, BCoV-ELISA kits cannot differentiate between infections caused by BCoV and those caused by CRCoV. In this study, we evaluated the hemagglutination inhibition (HI) test for CRCoV by comparing it with the virus neutralization (VN) test. Subsequently, we evaluated the seroprevalence of CRCoV in 383 dog serum samples collected from South Korea utilizing the HI test. The HI test for CRCoV showed a strong correlation with the VN test (R = 0.83, p < 0.001). The analysis of seroprevalence revealed that 52.2% (95% confidence interval [CI], 47.2%-57.1%) of the Korean dog serum samples were positive. The seroprevalence exhibited varied with age, with a positivity rate of 43.9% in dogs under 1 year of age and 66.7% in dogs aged 3 to 5 years (odds ratio, 2.54; 95% CI, 1.43-4.59). In conclusion, the HI test to monitor CRCoV antibody proved to be closely related to the VN test. Furthermore, over half of the dogs in Korea tested positive for CRCoV antibodies. These findings contribute to a better understanding of the sero-epidemiology of CRCoV.

• Korean Journal of Veterinary Research
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• v.64 no.1
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• pp.3.1-3.8
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• 2024

Canine distemper virus (CDV), canine adenovirus type 2 (CAV-2), canine parvovirus (CPV), and canine parainfluenza virus 5 (CPIV-5) are the major viral pathogens in dogs. Despite the availability of vaccines for dogs against these 4 viral pathogens, investigations of antibodies against these pathogens have rarely been reported in South Korea. In this study, we investigated the recent incidence of viral diseases in dogs and conducted sero-surveillance for CDV, CAV-2, CPV, and CPIV-5 in Korean dogs. The most frequently diagnosed canine viral disease in Korean dog samples from 2000 to 2022 was CPV infection, which accounted for 48.7% (464/953) of the cases. A total of 400 dog serum samples collected between 2019 and 2022 were screened for the presence of virus-neutralizing antibodies against CDV, CAV-2, CPV, and CPIV-5. The overall seropositivity rates for CDV, CAV-2, CPV, and CPIV-5 were 83.8%, 77.8%, 99.3%, and 82.0%, respectively. The protection rate against CPV was the highest (98.3%) and that against CAV-2 was the lowest (44.8%) in dog sera. Male and female dogs showed no significant differences in seropositivity rates. CDV and CPIV-5 seropositivity increased with age in dogs, and the highest incidence and seropositivity rates of CPV indicated that Korean dogs have been continuously exposed to wild CPV, and that CPV is a pathogen that urgently requires attention among canine viral diseases.

• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1960-1965
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• 2015

Rabbit hemorrhagic disease virus (RHDV) is highly contagious and often causes fatal disease that affects both wild and domestic rabbits of the species Oryctolagus cuniculus. A highly pathogenic RHDV variant (RHDVa) has been circulation in the Korean rabbit population since 2007 and has a devastating effect on the rabbit industry in Korea. A highly pathogenic RHDVa was isolated from naturally infected rabbits, and the gene encoding the VP60 protein was cloned into a baculovirus transfer vector and expressed in insect cells. The hemagglutination titer of the Sf-9 cell lysate infected with recombinant VP60 baculovirus was 131,072 units/50 μl and of the supernatant 4,096 units/50 μl. Guinea pigs immunized twice intramuscularly with a trial inactivated RHDVa vaccine containing recombinant VP60 contained 2,152 hemagglutination inhibition (HI) geometric mean titers. The 8-week-old white rabbits inoculated with one vaccine dose were challenged with a lethal RHDVa 21 days later and showed 100% survival rates. The recombinant VP60 protein expressed in a baculovirus system induced high HI titers in guinea pigs and rendered complete protection, which led to the development of a novel inactivated RHDVa vaccine.

• Health Policy and Management
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• v.33 no.1
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• pp.65-74
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• 2023

Background: The government should find ways to improve the effectiveness of the policies to control the incidence and mortality of the infectious disease. The purpose of this study is to find out whether the trust in the government's ability to respond to coronavirus disease 2019 (COVID-19) affects the quarantine and hospitalization rate, incidence and mortality rates of COVID-19 and quarantine rules compliance in each region of Korea. Methods: The subject of this study is 250 regions (si·gun·gu) in Korea, and the 2020 Community Health Survey data from the Korea Disease Control and Prevention Agency (KDCA) was used for the trust in the government's ability to respond to COVID-19, quarantine and hospitalization rate and quarantine rules compliance. For the incidence and mortality of COVID-19 and community factors, data was obtained from KDCA and Korean Statistical Information Service. Path analysis was used to find out the degree of inter-variable influence, and community factors (socio-demographic factors, community health factors, and health behavior factors) were used as control variables. Results: The regional disparity in key variables showed that the late pandemic period cumulative incidence and mortality of COVID-19 were large, while the early pandemic period quarantine and hospitalization rate and quarantine rules compliance were small. Path analysis showed that when community factors were controlled, the trust in government was statistically significant in all of the late pandemic period cumulative incidence (p=0.024) and mortality (p=0.017), and quarantine rules compliance (p=0.011). Conclusion: This study revealed that the higher the trust in the government's ability to respond to COVID-19, the lower the COVID-19 mortality and the higher the quarantine rules compliance at the regional level in Korea. This suggests that when the government implements healthcare policies to control infectious diseases, it is necessary to consider trust to improve policy compliance and control the mortality of the disease and maintain high trust through several effective methods.

• Korean Journal of Veterinary Research
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• v.43 no.2
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• pp.311-314
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• 2003

Pacheco's disease (PD) is a highly contagious, acute disease of psittacines caused by a herpesvirus. Five 56-day-old dead parakeets (Neophema bourkii) were submitted to the National. Veterinary Research & Quarantine Service for diagnosis. At necropsy, principle lesions were seen in the pancreas, which were hard, whitish, nodular and atrophic resulting in distortion of the duodenal loop. Histologically, lymphocytic pancreatitis with eosinophilic intranuclear inclusions syncytium-formed acinar epithelium was prominent. In the brain, marked focal gliosis and perivascular lymphocytic cuffing were observed. On the electron microscopy examination, various forms of viral particles were found in both the nucleus and cytoplasm of acinar epithelium of pancreas, identified as a herpesvirus. These results were suggested that the cases were diagnosed as PD in the parrakeet.