• Journal of Life Science
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• v.9 no.5
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• pp.570-574
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• 1999

Investigate the epidemics for influenza outbreaks. The outbreak pattern of the internal patients housed in the 10 designated hospitals was monitered to investigate and the characteristics of the virus isolates are as follows. 232 strains of influenza virus was isolated from the oral specimen of 1,320 respiratory disease patients in Pusan from Oct. 1998 to Jun. 1999. Among these isolates, 222 strains were A-type and the rest were B-type. The outbreak pattern for sex-and age-groups is as follows. The male outbreak was similar to the female outbreak: male outbreak, 47.4% and female outbreak, 52.5%. Most of the patients were less than 10 years old. The monthly influenza outbreak was consistent from Dec. 1998 to Apr. 1999. and The 113 strains from the A-type isolates were A/ Sydney/05/97(H3N2)-like, the 109 strains were A/Beijing/262/95(H1N1)-like, and all of the 10 B-type isolates were B/Harbin/07/94-like.

• Journal of Preventive Medicine and Public Health
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• v.41 no.3
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• pp.153-158
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• 2008

Objectives : This study describes a plan that was designed to prevent a measles outbreak that showed a changed outbreak pattern. This study is based on the epidemiological investigation of a measles outbreak in a preschool in Incheon, Korea, 2006. Methods : The subjects were 152 students at a preschool where a measles outbreak occurred. A questionnaire survey was conducted and serological testing for measles-specific IgM was preformed. Results : Of the fifteen confirmed, identified cases, eleven patients had been vaccinated with one dose, one patient had received two doses and three patients were unvaccinated. The three unvaccinated cases consisted of one 5-year-old child, one 3-year-old child and one 16-month-old infant. For the cases with one dose of the vaccination, there were 11 cases, which consisted of six 5-year-old children, two 4-year-old children, two 3-year-old children and one 2-year-old child. The case with two doses of the vaccination was one 4-year-old child. The attack rate of measles was 100% in the 0-dose group, 11.2% in the 1-dose group and 2.0% in the 2-dose group. The vaccine's efficacy was 88.8% in the 1-dose group and 98.0% in the 2-dose group. The vaccine effectiveness for the 2-dose group was higher than that of the 1-dose group. Conclusions : High coverage with a 2-dose vaccination should be maintained, and the vaccination should be given at the suitable time to prevent a measles outbreak with a changed outbreak pattern.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.803-810
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• 1998

Pullorum disease caused by Salmonella pullorum, has been considered as one of the most important diseases in both clinically and economically in poultry industry since it had been firstly reported in 1925 in Korea. This disease is still problem in the industry in this country even though several attempts have been made to eradicate the disease. As one of the trials to solve the problem, we investigated the pattern of the outbreak of the disease, isolated the causative agent, S pullorum and tested biochemical properties, antimicrobial susceptibility and plasmid profiles of the isolates. Outbreak of the disease based on the species was the highest in layer followed by in Korean native chick, and broiler. Daily mean mortality in vertical transmission (0.90%) was higher than that in horizontal (0.14%). There was no seasonal difference in the outbreak. Also, biochemical properties and antimicrobial susceptibility pattern of the isolates were same. However four different plasmid profiles of the isolates were observed. These results suggested that S pullorum isolates were different in the genotype while they were same in phenotypes.

• Korean Journal of Remote Sensing
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• v.20 no.5
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• pp.307-313
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• 2004

The trajectories of 8 autonomous profiling floats deployed in the Kuroshio Extension region in February 2001 are used to depict the circulation pattern at the surface and 2000db. The corresponding sea surface topography maps created from satellite altimeter and dynamic height climatology were compared with the tracks of nearly coincident floats and were found to agree well in most cases except for the period June 5 to 16 2001. It is shown that over the period the conspicuous breakaway of the floats from an expected path is possibly associated with the abnormal path of the Kuroshio Extension such as an outbreak event, as revealed by AVHRR infrared and SeaWiFS chlorophyll-a images and cruise data in cross sections.

• Journal of Preventive Medicine and Public Health
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• v.44 no.4
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• pp.185-189
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• 2011

Objectives: In 1995, an outbreak survey in Gozan-dong concluded that an association between fiberglass exposure in drinking water and cancer outbreak cannot be established. This study follows the subjects from a study in 1995 using a data linkage method to examine whether an association existed. The authors will address the potential benefits and methodological issues following outbreak surveys using data linkage, particularly when informed consent is absent. Methods: This is a follow-up study of 697 (30 exposed) individuals out of the original 888 (31 exposed) participants (78.5%) from 1995 to 2007 assessing the cancer outcomes and deaths of these individuals. The National Cancer Registry (KNCR) and death certificate data were linked using the ID numbers of the participants. The standardized incidence ratio (SIR) and standardized mortality ratio (SMR) from cancers were calculated by the KNCR. Results: The SIR values for all cancer or gastrointestinal cancer (GI) occurrences were the lowest in the exposed group (SIR, 0.73; 95% CI, 0.10 to 5.21; 0.00 for GI), while the two control groups (control 1: external, control 2: internal) showed slight increases in their SIR values (SIR, 1.18 and 1.27 for all cancers; 1.62 and 1.46 for GI). All lacked statistical significance. All-cause mortality levels for the three groups showed the same pattern (SMR 0.37, 1.29, and 1.11). Conclusions: This study did not refute a finding of non-association with a 13-year follow-up. Considering that many outbreak surveys are associated with a small sample size and a cross-sectional design, follow-up studies that utilize data linkage should become standard procedure.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.248-253
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• 2011

KFDA compiles the statistical data of food poisoning outbreaks two or more persons since 2002 in Korea and release them to the public on the web. There is a gap of outbreak number between the real situation and the reports. To reduce the gap, addition of sporadic individual case of food poisoning may be one of the solution method. The statistical data of Japan where food consumption pattern is similar to Korea, were used in this study to compare the ratio and the pattern between the outbreak cases two or more persons and individual cases. By doing so, the data of Japan regarding to outbreak cases two or more persons will be comparable to that of Korea. The data of 2002 and 2003 in Japan showed that sporadic individual cases were 43.3% in the total food poisoning cases. The individual cases occurred highly in unknown places (90-92.3%) and home (6.2-8.5%) whileas the outbreaks two or more persons occurred mostly in the place of restaurants (46.6-50.l%) and inns (9.2-9.8%). The food-borne pathogens attributed to the individual cases were C. jejuni (51.9%), Salmonella spp. (35.3%), and V. parahaemolyticus (9.8%) while those to the outbreak cases two or more persons were norovirus (31.3%), Salmonella spp. (20.8%), C. jejuni (15.5%) in Japan. The data of 2002-2009 between Korea and Japan showed the outbreak case report rate was 1:1.5 based on the total population number.

• Journal of Veterinary Clinics
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• v.34 no.2
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• pp.146-151
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• 2017

Six major outbreaks of highly pathogenic avian influenza (HPAI) occurred from 2003 to 2016 in Korea. Epidemiological investigations of each outbreak revealed that migratory birds were the primary source of the HPAI virus. During the last five years, the geographic transmission pattern of domestic HPAI seems to have extended from local to nationwide; therefore, it is necessary to identify specific locations in which poultry farms are at elevated risk for HPAI outbreak to enable targeted surveillance and other mitigation strategies. Here, a geographical information system (GIS)-based analysis was used to identify geographic areas at high risk for future HPAI incidents in Korea based on historical outbreak data collected between December 2003 and April 2016. To accomplish this, seven criteria were used to identify areas at high-risk for HPAI occurrence. The first three criteria were based on defined spatial criteria buffering of 200 bird migration sites to some defined extents and the historical incidence of HPAI outbreaks at the buffering sites. The remaining criteria were based on combined attribute information such as number of birds or farms at district levels. Based on the criteria established for this study, the most-likely areas at higher risk for HPAI outbreak were located in Chungcheong, Jeolla, Gyeonggi, and Gyeongnam provinces, which are densely populated poultry regions considered major poultry-production areas that are located along bird migration sites. The proportion of areas at risk for HPAI occurrence ranged from 4.5% to 64.9%. For the worst criteria, all nine provinces, including Jeju Island, were found to be at risk of HPAI. The results of this study indicate that the number of poultry farms at risk for HPAI outbreaks is largely underestimated by current regulatory risk assessment procedures conducted for biosecurity authorization. The HPAI risk map generated in this study will enable easy use of information by policy makers to identify surveillance zones and employ targeted surveillance to reduce the impact of HPAI transmission.

• Journal of Preventive Medicine and Public Health
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• v.34 no.2
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• pp.131-140
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• 2001

Objectives : During March-May, 2000, a measles outbreak occurred at Youngduk, Korea. This county is divided into two areas with different historical and socioeconomic background. The outbreak occurred in one of these areas. We conducted a comparative epidemiologic study on the two areas in order to evaluate the factors related to the epidemic. Materials and Methods : We selected two groups, grades 3 and 5 in a primary schools in each area. We investigated outbreak-related factors using parent-questionnaires, the vaccination history from the student's health record and the records concerning the recent measles-outbreak from the local health center. Serologic test on measles-IgG and -IgM antibody was done. Results : The infection rate was 31.5% for the epidemic area and 3.7% for non-the epidemic area according to clinical or serological criteria (p<0.001). No difference was seen in the measles vaccination rate, residence at the time of vaccination or past measles infection history between the two areas. In the epidemic area, the attack rate for the 4-6 year-old MMR booster group(20.5%) was higher than the non-booster group(32.4%), but was not found significantly. Vaccine efficacy was 29.6% in the epidemic area and 87.0% in the non-epidemic area (p<0.001). The IgG level and positive rate were significantly different between the two areas (median 10727 IU/ml, 98.9% in epidemic area; median 346 IU/ml, 85.9% in the non-epidemic area, p<0.001). However, the IgG level and positive rate between the measles-cases and non-cases were not significantly different. Conclusions : This outbreak took place in mostly vaccinated children. These results suggest that a reduction of herd immunity for immunity failure after vaccination may be one of the feasible factors related to the outbreak pattern in the two areas. The results of the IgG level and positive rate suggest that re-establishment of a normal value for IgG level and of a qualitative method for IgG are needed.

• Korean Journal of Veterinary Service
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• v.32 no.4
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• pp.315-323
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• 2009

Foot-and-mouth disease (FMD) virus exists in seven serotypes and is known to be a highly contagious disease that is hard to eradicate from the world. The O, A, Asia1 and SAT2 serotypes commonly infected cattle, sheep and goats during 2007~2009 throughout the world. In particular, the outbreak of the Asia1 serotype in China appeared in all areas from 2005 and is still present. Surprisingly, in 2009, Taiwan reported the first outbreak of the type O serotype since 2001. Then type A appeared in China for the first time since the early 1960s. The virus shows a close relationship to the viruses from Southeast Asia suggesting one or more recent introductions into China in the OIE reports. Recently the subtype of A/Iran05 spread to nearby countries exhibiting genomic evolution. The use of molecular epidemiology is an important tool in understanding and consequently controlling the FMD virus. The phylogenetic analysis with VP1 gene was especially useful for molecular epidemiological studies and showed the same pattern which matches with serotype classification. This paper describes basic information about the disease, and the serotype-specific characteristics and evolution to perform molecular epidemiological analysis. Furthermore, we show the importance of the genetic evolution on the FMD serotypes in global surveillance and molecular epidemiology of FMD for outbreak investigation.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.85-87
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• 2013

An outbreak of Staphylococcus aureus infections occurred in a university with an enrollment of 80 students in the city of Daejon, Republic of Korea. All nine S. aureus isolates from patients (n = 7), staff members (n = 1), and the fried chicken served as the lunch (n = 1) harbored the enterotoxin A gene and showed an identical antibioticresistant profile, PFGE banding pattern (STAS16.001), and sequence type, ST 6. These results suggested that the outbreak was associated with eating the fried chicken that had been handled by an infected staff member. This case report demonstrated a practical approach to identifying the source and transmission of an infection.