title: Comparative pathology of pigs infected with Korean H1N1, H1N2, or H3N2 swine influenza A viruses.
abstract: BACKGROUND
  The predominant subtypes of swine influenza A virus (SIV) in Korea swine population are H1N1, H1N2, and H3N2. The viruses are genetically close to the classical U.S. H1N1 and triple-reassortant H1N2 and H3N2 viruses, respectively. Comparative pathogenesis caused by Korean H1N1, H1N2, and H3N2 SIV was evaluated in this study.
  
  
  RESULTS
  The H3N2 infected pigs had severe scores of gross and histopathological lesions at post-inoculation days (PID) 2, and this then progressively decreased. Both the H1N1 and H1N2 infected pigs lacked gross lesions at PID 2, but they showed moderate to severe pneumonia on PID 4, 7 and 14. The pigs infected with H1N1 had significant scores of gross and histopathological lesions when compared with the other pigs infected with H1N2, H3N2, and mock at PID 14. Mean SIV antigen-positive scores were rarely detected for pigs infected with H1N2 and H3N2 from PID 7, whereas a significantly increased amount of viral antigens were found in the bronchioles and alveolar epithelium of the H1N1infected pigs at PID 14.
  
  
  CONCLUSIONS
  We demonstrated that Korean SIV subtypes had different pulmonary pathologic patterns. The Korean H3N2 rapidly induced acute lung lesions such as broncho-interstitial pneumonia, while the Korean H1N1 showed longer course of infection as compared to other strains.
authors.forename: Kwang-Soo
authors.initials: KS
authors.lastname: Lyoo
authors.forename: Jeong-Ki
authors.initials: JK
authors.lastname: Kim
authors.forename: Kwonil
authors.initials: K
authors.lastname: Jung
authors.forename: Bo-Kyu
authors.initials: BK
authors.lastname: Kang
authors.affiliation: Viral Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea. sds1@kribb.re.kr.
authors.forename: Daesub
authors.initials: D
authors.lastname: Song
mesh_terms: D000818:Animals; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification / Q000502:physiology*; D057221:Influenza A Virus, H1N2 Subtype / Q000302:isolation & purification / Q000502:physiology*; D053122:Influenza A Virus, H3N2 Subtype / Q000302:isolation & purification / Q000502:physiology*; D008168:Lung / Q000473:pathology / Q000821:virology; D009976:Orthomyxoviridae Infections / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D056910:Republic of Korea; D013552:Swine; D013553:Swine Diseases / Q000473:pathology* / Q000821:virology