Swine influenza is a respiratory infectious disease in pigs caused by Orthomyxoviridae influenza virus A. As a multihost pathogen, the virus can infect humans, birds, and pigs and has pandemic potential due to rapid mutation rate. This study investigated the seroprevalence of influenza A antibodies in pigs in Chungbuk Province to overview its temporal and spatial distribution. From March to November 2021, blood samples collected for swine fever and foot-and-mouth disease antibody tests from swine farms located in Cheongju, Jincheon, Jeungpyeong, and Goesan within the jurisdiction of the Chungbuk Animal Health Laboratory were used. Blood samples from both sows and growing pigs were collected. Additionally, three farms participating in the Expendable Disease Guidance Support Project were chosen to investigate the seroprevalence status by parity of sows and age of piglets. A total of 468 sows and 1,519 growing-finishing pigs were employed in this study. The results showed that Jincheon had the highest seropositivity rate, suggesting that more effort should be made in biosecurity to prevent mechanical transmission, given the close proximity of farms. The analysis of antibody levels in farms targeted by the Expendable Disease Guidance Support Project could suggest that once the virus enters a farm, it spreads throughout the entire pig population regardless of age. Farms that were positive in the first half of the year remained positive in 86% of cases in the second half, suggesting continuous infection within the farm unless depopulation or all-in-all-out practices are implemented. Moreover, 67% of farms that were negative in the first half remained negative in the second half, and farms managed by the same person showed identical antibody change patterns, indicating that the swine influenza virus can be transmitted by humans or vehicles. The results highlight the need for further analysis of biosecurity systems and geographical risk factors.

서 론
재료 및 방법
    공시재료
    검사방법
    통계분석
결 과
    월별 항체 양성률
    지역별 항체 양성률
    소모성 질병 지도지원 사업 농가 항체 양성률
    농가별 항체 보유 현황 변화
고 찰
감사의 글
REFERENCES

• Jin-Young Park(Chungbuk Province Veterinary Service Laboratory, Cheongju 28153, Korea)
• Seongjoo Yoon(Department of Aviation Services, Cheongju University, Cheongju 28503, Korea)
• Kyung-Duk Min(Laboratory of Veterinary Epidemiology, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea) Corresponding author
• Beom-Jun Lee(Laboratory of Veterinary Public Health, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea) Corresponding author