Epidemiological characteristics of 2002 outbreak of classical swine fever in Korea |
Choi-Kyu Park, Jae-Young Song, Sung-Hwan Wee, Eune-Sub Lee, Hachung Yoon, Oun-Kyeong Moon, Eun-Jin Choi, Hyang-Mi Nam |
National Veterinary Research and Quarantine Services |
2002년 한국에서 발생한 돼지콜레라의 역학적 특성 |
박최규, 송재영, 위성환, 이은섭, 윤하정, 문운경, 최은진, 남향미 |
국립수의과학검역원 |
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Abstract |
This paper described the epidemiological characteristics of 2002 outbreak of classical swine fever (CSF) in Korea. A total of thirteen CSF-infected farms could be classified into two clusters according to the location and time of outbreak. Two farms located in the same county of Gangwon province and 11 farms located in several different districts of Incheon metropolitan/Gyeonggi province were identified as CSF-infected from April 16 to 30 and from October 7 to December 21 in 2002, respectively. As the result of epidemiological analysis, the two clusters of outbreaks were turned out to be independent epidemics which had different sources of virus introduction. Three farms were found to have been infected primarily; one located in Cheolwon county of Gangwon province and two located in Kangwha county of Incheon metropolitan area. The most likely factors of virus introduction into these primary infected farms were considered to be direct or indirect contact by foreign workers and/or owners of the infected farms who had come back from traveling in China before outbreaks. This was supported by the genetic typing of CSF viruses isolated from the pigs of infected farms. All the virus isolates of 2002 outbreak were found to be genetic type 2, whereas the viruses isolated before 2000 were type 3 and the reference strains, such as attenuated live vaccine virus (LOM strain) and high virulent challenge virus (ALD strain), were type 1. Accordingly, we concluded that the 2002 CSF outbreak must have been caused by a newly introduced virus from overseas and the type 3 virus must have been eradicated after the last outbreak of 1999 by the national CSF eradication campaign which were implemented since 1996. Based on the combined analysis of epidemiological data and genetic typing, the transmission routes of classical swine fever virus were found to be the movement of vehicles (60%) and persons (10%), neighbourhood spread (20%) and unknown (10%). It is expected that the analyzed data and findings of classical swine fever outbreak epidemic could be very useful to establish the disease control and eradication program for the country in the future. |
Key Words:
classical swine fever (CSF), epidemiology, transmission, Korea |
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