The Role of Pigs in Interspecies Transmission

Publisher Website
Google Scholar
Abstract
Pigs are an important host in influenza virus ecology since they are susceptible to infection with both avian and human influenza A viruses, often being involved in interspecies transmission, facilitated by regular close contact with humans or birds. This cross-species transfer of viruses to pigs can lead to co-infections with subsequent opportunities for genetic reassortment of influenza A viruses, and as a result ‘new’ or previously unrecognised viruses can emerge. Pigs are known to be susceptible to influenza A viruses of most haemagglutinin subtypes although only three serotypes, H1N1, H3N2 and H1N2, predominantly infect pigs worldwide. The changing epidemiology of influenza in poultry and humans has direct implications for the circulation of viruses in pigs. Significantly H9N2 is increasingly being detected in pigs in Asia together with occasional spillover of H5N1 highly pathogenic avian influenza from avian species. The apparent natural selection and persistence of viruses containing mixtures of avian, swine and human influenza virus genes demonstrates the importance of optimal gene constellations that permit efficient replication and intraspecies transmission. The genesis of new influenza virus strains principally through reassortment but also by host adaptation does present theoretical opportunities for the production of pandemic strains in pigs, so their potential role in interspecies transmission remains important.

This publication has 0 references indexed in Scilit: