I am sure many of your remember the “swine flu” epidemic back in the ‘70s.  What you may not know is that many viruses can cross species lines.  The reservoirs for many diseases may be animals: examples include Ebola and possibly HIV.  Unlike some respiratory viruses, the influenza A virus can cross species lines.  Swine play a significant role in the transmission of influenza virus.  Not only can they transmit the common influenza virus known by its scientific name, H1N1, but they may also transmit influenza viruses that have mutated to a different genetic type.  These variant viruses would not have been covered by the flu vaccine for the year and, therefore, people are more susceptible to infection.

However, the H1N1 strain is the easiest to cross from swine to human. This association with influenza transmission and swine association has recently been studied and reported. North Carolina is the second largest swine producing state in the U.S.  Researchers found that the incidence of influenza like illness (ILI) occurred earlier in counties with more swine farms, especially when H1N1 was the predominant strain of the season. In Ohio and Michigan cases of a genetic variant influenza virus caused significant infection and serious disease in patients who were exposed and had direct exposure to swine barns.  For the general population, county fairs are a concern, and for that reason public precautions include limiting the time swine are on the fairgrounds and the time you spend in the barns, hand washing, and limiting eating and drinking in swine barns.