Three major SIV subtypes are prevalent: H1N1 (classical swine H1N1 and avian-like H1N1), H3N2 (triple reassortant H3N2 and human-like H3N2), and H1N2 [2, 7, 8, 9, 10, 11] . Pigs are also susceptible to and show clinical signs when infected with pandemic (H1N1) 2009 virus (referred to hereafter as H1N1pdm) [12] , which emerged in April 2009 in North America [13] , arising at least in part from contemporaneous SIV. To date H1N1pdm has been found in a few swine farms [12, 14, 15] , which further demonstrates a two-way process of both gene and virus trafficking between humans and pigs. Though H1N1pdm has remained antigenically and genetically stable in humans since its emergence, a novel reassortant SIV containing a H1N1pdm-like NA and seven other genes from triple-reassortant H1N2 and European ''avian-like'' H1N1 viruses was identified in early 2010 [16] , and that same year H1N1pdm was shown to be evolving genetically at a faster pace in pigs than it was in humans [12, 15, 17] . Effective control of circulating influenza viruses in swine populations is key to reducing consequent genesis of novel pandemic strains that threaten the health of both humans and animals.