Influenza A virus infections in swine: pathogenesis and diagnosis.

摘要: Influenza has been recognized as a respiratory disease in swine since its first appearance concurrent with the 1918 "Spanish flu" human pandemic. All influenza viruses of significance are type A, subtype H1N1, H1N2, or H3N2 viruses. infect epithelial cells lining surface tract, inducing prominent necrotizing bronchitis and bronchiolitis variable interstitial pneumonia. Cell death is due to direct virus infection insult directed by leukocytes cytokines innate immune system. The most virulent consistently express following characteristics infection: (1) higher more prolonged replication, (2) excessive cytokine induction, (3) replication lower tract. Nearly all viral proteins contribute virulence. Pigs susceptible both avian viruses, which often results gene reassortment between these endemic receptors on tract major determinants from other hosts. polymerases, especially PB2, also influence cross-species infection. Methods diagnosis characterization that have improved over years, driven availability new technologies necessity keeping up changes virus. Testing oral fluids pigs for antibody recent development allows efficient sampling large numbers animals.