• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.53-58
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• 2002

To better understand the reservoir host range and distribution of hantaviruses in small mammal populations in Korea, a serological survey was conducted on 1,375 wild rodents and 62 insectivores captured in seven provinces during the six-year period, 1995 to 2000. As determined by the indirect immunofluorescent antibody (IFA) test, 90 ($13.1\%$) of 685 Apodemus agrarius, 47 ($13.6\%$) of 345 Apodemus peninsulae, and 4 ($6.5\%$) of 62 Crocidura laciura were seropositive against the Hantaan virus, while 38 ($13.5\%$) of 282 Eothenomys regulus were seropositive against the Puumala virus. Serological evidence for hantavirus infection was not found in 50 Microtus fortis, six Micromys minutus, six Mus musculus, and one Cricetulus triton. Our serological data indicate that hemorrhagic fever with renal syndrome (HFRS)-related hantaviruses are widely distributed in indigenous rodents in Korea. Particularly noteworthy was the high seropositivity rates among Apodemus peninsulae and Eothenomys regulus captured in certain mountainous regions, suggesting that HFRS may be under-reported among nearby residents or among individuals who might visit such areas for recreational or occupational purposes.

• Korean Journal of Veterinary Service
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• v.27 no.4
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• pp.345-354
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• 2004

Two cases of classical swine fever (CSF) disease have broken out in Cheolwon (7 April, 2002). The suspected pig herds were huddled together because of high fever (over $40^{\circ}C$) and showed remarkable decrease of the leukocytes. The staggering gait related to posterior weakness, constipation and lethargy, hyperemia, hemorrhagic lesions (on the skin, muzzle, ears, limbs, tail and inner part of legs) and conjunctivitis with dirty streaks below the eyes were observed. The inflammation in the lung, infarction in the spleen, swelling and hemorrhage in lymph nodes, kidney, intestine, heart and cheese like purulent inflammation of the tonsil were observed. The ulcers of the colon were also detected. Several clinical and laboratory techniques including blood test, histo-pathological examinations, indirect fluorescent antibody (IFA) test and RT-PCR test were applied to diagnose the disease. Inoculation test on PK-15 cell was also performed. The necrosis of the lymphatic cells and infiltration of the vessel circumferential cells in the brain and lymph organs were commonly viewed. The proliferation of the glia cell (gliosis) in the lymph was particular. Cytopathogenic effect (CPE) and specific fluorescent-bright-green areas (with IFA) appeared in PK-15 cells inoculated with suspected blood plasma. The IFA test on the epithelial and mucous membrane cells of tonsil was positive. RT-PCR technique required more working hours and labor than other techniques in this examination but it was useful because of the sensitivity to the CSF viral gene.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.35.1-35.13
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• 2021

Background: African swine fever (ASF) is an infectious viral disease of domestic pigs that presents as a hemorrhagic fever, and for which no effective vaccine is available. The disease has a serious negative social and economic impact on pig keepers. There is limited information on the potential risk factors responsible for the spread of ASF in South Kivu. Objective: The aim of this study was to determine the potential risk factors associated with ASF infection in suspected ASF virus (ASFV)-infected pigs. Methods: We sampled whole blood from 391 pigs. Additionally, 300 pig farmers were interviewed using a structured questionnaire. Viral DNA was detected by using the real-time polymerase chain reaction technique. Results: The majority of pigs sampled, 78% (95% confidence interval [CI], 74.4-82.6), were of local breeds. Over half, 60.4% (95% CI, 55.5-65.2), were female, and most of them, 90.5% (95% CI, 87.6-93.4), were adult pigs (> 1 year old). Viral DNA was detected in 72 of the 391 sampled pigs, indicating an overall infection rate of 18.4% (95% CI, 14.5-22.4). Multivariable logistic regression analysis revealed several risk factors positively associated with ASFV infection: feeding with swill in pen (odds ratio [OR], 3.8; 95% CI, 2.12-6.77); mixed ages of pigs in the same pen (OR, 3.3; 95% CI, 1.99-5.57); introduction of new animals to the farm (OR, 5.4; 95% CI, 1.91-15.28). The risk factors that were negatively (protective) correlated with ASFV positivity were the presence of male animals and the use of an in-pen breeding system. Conclusion: Local pig farmers should be encouraged to adopt proper husbandry and feeding practices in order to increase the number of ASF-free farms.

• Journal of Veterinary Science
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• v.22 no.5
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• pp.71.1-71.12
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• 2021

Background: African swine fever (ASF) is a hemorrhagic fever occurring in wild boars (Sus scrofa) and domestic pigs. The epidemic situation of ASF in South Korean wild boars has increased the risk of ASF in domestic pig farms. Although basic reproduction number (R₀) can be applied for control policies, it is challenging to estimate the R₀ for ASF in wild boars due to surveillance bias, lack of wild boar population data, and the effect of ASF-positive wild boar carcass on disease dynamics. Objectives: This study was undertaken to estimate the R₀ of ASF in wild boars in South Korea, and subsequently analyze the spatiotemporal heterogeneity. Methods: We detected the local transmission clusters using the spatiotemporal clustering algorithm, which was modified to incorporate the effect of ASF-positive wild boar carcass. With the assumption of exponential growth, R₀ was estimated for each cluster. The temporal change of the estimates and its association with the habitat suitability of wild boar were analyzed. Results: Totally, 22 local transmission clusters were detected, showing seasonal patterns occurring in winter and spring. Mean value of R₀ of each cluster was 1.54. The estimates showed a temporal increasing trend and positive association with habitat suitability of wild boar. Conclusions: The disease dynamics among wild boars seems to have worsened over time. Thus, in areas with a high elevation and suitable for wild boars, practical methods need to be contrived to ratify the control policies for wild boars.

• Pediatric Infection and Vaccine
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• v.16 no.1
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• pp.54-60
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• 2009

Purpose : Yellow fever, a mosquito-borne viral hemorrhagic fever, is one of the most lethal diseases. Recently there have been an increasing number of Korean children who have travelled to yellow fever endemic zones and were administered yellow fever vaccine (YFV). Therefore, we carried out this study to provide child travelers with safety information of YFV. Methods : This study was conducted at the International Clinic of National Medical Center in Seoul between April 2007 and June 2008 for the evaluation of adverse events of YFV. One hundred twenty-five children received YFV (17-DD) and were prospectively monitored for adverse events through telephone interviews on day 3, 6, 9, 16, 23 and 30 after vaccination. Results : Adverse events were observed in 31 (24.8%) of 125 child travelers who received the YFV. The mean age was 12.5${\pm}$5.0 years. Sixty-six of the child travelers (52.8%) were males. The common adverse events were pain in 11 (8.8%), swelling in 8 (6.4%) and redness in 7 children (5.6%) at the injection site. The systemic adverse events included mild fever in 5 (4.0%), headache in 5 (4.0%), cough in 4 (3.2%), abdominal pain in 3 (2.4%), and vomiting in 2 children (1.6%). Most of the adverse events were detected within 7 days of administration and there were no differences in adverse events by gender or age. All travelers who had complained of symptoms improved spontaneously or following symptomatic treatment. Conclusion : This study showed that YFV is well-tolerated and there were no reports of severe adverse events. Studies are ongoing to clarify the cause and risk factors for rare adverse events.

• Journal of Preventive Medicine and Public Health
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• v.32 no.3
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• pp.269-275
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• 1999

Background : In April 6, 1990, a male researcher who has worked at a research unit at the Basic Research Building of Seoul National University(SNU) College of Medicine admitted to SNU Hospital due to persistent fever. He was diagnosed serologically as hemorrhagic fever with renal syndrome(HFRS). Another female researcher in the same unit was also diagnosed as HFRS at the same hospital several days later. Epidemic investigation of HFRS was conducted to determine the magnitude of the problems since these two cases were strongly suspected to have laboratory-acquired infections of HFRS. Methods : All researchers and employees working at the Basic Research Building(BRB) of SNU College of Medicine as of April 1, 1996 were recruited for the study, information on symptoms of HFRS and history of contact to experimental animals were collected by self-administered questionnaires and serological tests among study subjects were also conducted by indirect immunofluorescent antibody(IFA) to hantavirus. The experimental animals were also serologically tested for infection with hantavirus by IFA. Results : Among 218 surveyed, six researchers and an animal caretaker had hantavirus antibodies above 1:20 in IFA titer. Five of seven sero-positive subjects had antibodies above 1:640 in IFA titer and had shown clinical symptoms compatible to HFRS during Jan. 1 to Apr, 20, 1996. The sero-positive persons had handled animals more frequently than sero-negative persons (OR, 19,68; 95% Cl, 1.11-350.40) and handling animals at the animal quarter at School of Public Health(SPH) had shown consistently higher risk to get infected with hantavirus irrespective of types of animals handled (OR, 4.90-6.37). Sero-positivity of rats of the aniamal quarter at BRB was 30-60%, whereas 80% of rats at SPH tested were shown sero-positivity. Conclusion: There was a epidemic of HFRS in research units of a medical school during the period from Jan. through Apr, Further investigation is needed to determine the extent and the mode of transmission of the laboratory-acquired infection with hantavirus in other research facilities.

• Journal of agricultural medicine and community health
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• v.17 no.2
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• pp.93-102
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• 1992

The epidemic of tsutsugamushi disease, along with hemorrhagic fever with renal syndrome(HFRS) and leptospirosis, has been ingrowing concern as it occupies a considerable proportion of the so-called seasonal febrile illnesses in autumn in Korea. This study was conducted to describe certain epidemiologic characteristics of the reported cases of the tsutsugamushi epidemic in Chollanamdo province in 1991. The findings could be summarized as follows: 1. Among three seasonal febrile illnesses in Autumn, tsutsugamushi disease occupied 91.9 percent of whole serologically confirmed cases. 2. Male-female sex ratio was 1 : 1.8. Majority of cases (77.4% in men, 65.1% in female) were in older age group (>=50 year of age). 3. Date of disease onset were distributed between late September and November. The 67.4% of cases were developed from October 21 to November 10, 1991. 4. The 41.5% of cases were reported from southern maritime districts. Reported dates of index cases and median cases were earliest in inland districts followed by southern maritime and latest in western maritime districts. 5. Most frequently reported clinical symptoms were chill (100%), high fever (100%), headache (81.7%), and skin eruption (70.4%).

• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.540-563
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• 1998

This Study has been carried out to make a recommendation for the next amendment of the Infectious Disease Prevention Act with a specific focus on the kind of notifyable disease. Korean, Japanese, German, U.S, English and French acts on infectious diseases prevention were reviewed, compared with and analized in regards of numbers and kinds of notifyable infectious diseases and their tendency of amendments. An criteria was designed to assess the level of validity of diseases to be designated in the act. Four items, the fatality (greater than 10% or not), the possibility to make a big epidemic, the availability of efficient vaccination and the usefulness of isolation, are used in the assessment. This index is applied to the diseases in Korean and other countries' Infectious Disease Prevention Acts. Results are as follows: 1. The Korean Infectious Disease Preventon Act has a unique way of classifying the notifyable infectious disease, that is, the first, the second and the third class. But the author cannot find the basis of classification. No other countries reviewed have the similar classification. 2. The ten diseases, cholera, plague, yellow fever, diphtheria, typhoid fever, poliomyelitis, rabies, tetanus, malaria, and meningococcal meningitis are designated as the notifyable diseases not only in Korea but also in Japan, Germany, United States, England and france. 3. Thirty seven diseases including small pox, Lassa fever, anthrax, influenza, German measles, Legionellosis, infection with E. coli O157:H7, Q-fever, brucellosis, Lyme disease are designated as legal disease at least one of the above mentioned countries. 4. The Korea has been coped with the change of the infectious disease occurrence for last fifty years in amendment of the Infectious Disease Prevention Act. 5. Japan has a special infectious surveillance system composed of 3,880 clinics throughout the whole country. 6. Germany has classified infectious diseases in five categories which are based on seriousness of disease. Any confirmed death, cases and suspected cases in class I should be reported within 24 hours. But only confirmed death and cases in class II, but not suspected cases, are reportable in Germarny. 7. Plague, bacillary dysentery, pertussis, mumps, Japanese encephaltis and Korean hemorrhagic fevers are diseases with high credits validity index among Korean legal disease. 8. German measles, anthrax, E. coli O157 : H7 infection, Lassa fever, Q-fever, brucellosis are high in validity index among those which are not designated in Korea but designated in other countries. In conclusion, the Korean Infectious Disease Prevention Act has well been coped with the changes of infectious disease occurrence for last fifty years, but the classification basis and the validity of diseases to be designated as legal diseases is worth reevaluating.

• Pediatric Infection and Vaccine
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• v.27 no.2
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• pp.140-146
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• 2020

Dengue fever (DF) is endemic throughout tropical and subtropical regions; however, it is not endemic in Korea. Imported infectious diseases should be suspected when encountering returned travelers with non-specific symptoms such as fever, rash, and headache. Persistent vomiting, abdominal pain, hemorrhagic tendency, hepatic enzyme abnormalities, and proteinuria are risk factors for the development of severe DF in a patient with DF. Severe hyperglycemia is also known to be related to poor prognosis in acute illness, and with certain underlying diseases that present with hyperglycemia, such as diabetes, it is related to the progression of severe DF. We report a DF case with severe hyperglycemia in an adolescent returning from India. Pediatric DF cases reported in Korea were also reviewed.

• Microbiology and Biotechnology Letters
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• v.43 no.1
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• pp.22-30
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• 2015

CSF is a major concern for the swine industry, representing currently the most epizootically dangerous disease to the species. Numerous CSFV isolates with various degrees of virulence have already been isolated worldwide, ranging from low virulent strains that do not result in any apparent clinical signs to highly virulent strains that cause a severe per acute hemorrhagic fever with very high mortality. The molecular epidemiology of CSFVs has proven to be an essential tool for effective disease control and the development of safe and effective vaccines. Therefore, this study cloned and sequenced local CSFV isolates, and conducted a phylogenetic analysis based on the E2 glycoprotein encoding sequences.The RNA was extracted from PK15 cell culture passaged CSFV isolates, the cDNA prepared, and the complete E2 gene amplified with a product size of 1186 bp. The gelpurified PCR product was cloned into a pGEMT easy vector and the positive clone commercially sequenced. Aligning the nucleotide (1119 bp) and amino acid (373) sequences with 29 reference strains revealed nucleotide and amino acid sequence identities of 82.60-97.80% and 88.70-98.70%, respectively, indicating a higher mutation rate of the field CSFV strains. The phylogenetic analysis based on the complete E2 amino acid sequences also revealed a reliable differentiation of all the analyzed strains into specific genetic groups and subgroups, plus the local isolate (CSFV-E2) was found to cluster with the CSFV subgroup 2.2. Thus, the full-length E2 cds proved to be most suitable for a reliable and statistically significant phylogenetic analysis of CSFV isolates.