The ongoing outbreak of Swine Flu / novel influenza A (H1N1) highlights one of the many serious public health risks that industrial food animal production (IFAP) poses on a global scale. It is known that pigs are “mixing vessels” for influenza viruses (for swine, avian and human flu), and it is believed that the last two flu pandemics, in 1957 and 1968, broke out when avian flu and human flu viruses mixed genetically with pig viruses to create a new flu virus that was transferred back to people. It has also been suggested that the 1918 Spanish Flu originated from pigs (Chasing the Fickle Swine Flu, March 7, 2003, Science).
Insufficient evidence is available to definitively determine whether the current swine flu outbreak originated from IFAP swine operations. However, through analyses of genome sequences generated by the Centers for Disease Control and Prevention (CDC) from current virus isolates, Columbia University researchers have proposed two swine-related genetic ancestors of the current virus. Of these, one that accounts for six of the eight genetic segments of the virus has been identified as the H3N2 virus, a triple reassortment of swine, avian and human virus first isolated in pigs on a North Carolina swine operation in August of 1998. (Evolution of Swine H3N2 Influenza Viruses in the United States, Journal of Virology, September 2000) The other two segments are believed to be from swine viruses of Eurasian origin (Trifonov, 2009). Read More >