Precautions for People Attending Fairs with Swine

As late summer is fair season across the country, Friday,  the Centers for Disease Control (CDC) has issued interim precautions for people when interacting with swine.  The number of cases of infection with H3N2v viruses with the M gene from the 2009 H1N1 virus detected in the United States since July 2011 has risen and now totals 29 [Hawaii (1), Indiana (7), Iowa (3), Ohio (10), Maine (2), Pennsylvania (3), Utah (1), and West Virginia (2)]. Twenty-three of these cases reported swine contact prior to illness onset. Among those 29 cases, 19 cases were associated with fairs where swine were present. Most human cases of the virus infection resulted in signs and symptoms of influenza  and all cases have recovered fully.

The USDA reports  swine influenza surveillance, indicates this swine H3N2 virus with the pandemic M gene  (thus the designation H3N2v) has been detected in swine in a number of U.S. states. It is possible that acquisition of the M gene from the 2009 H1N1 virus may allow H3N2v viruses to be more transmissible from pigs to people and from person-to-person. Keep in mind, swine are the “mixing vessel” for avian , human, and swine influenza viruses.