Pandemic 2009 influenza A(H1N1) virus, which spread to more than 200 countries worldwide, has undergone genetic reassortment in pigs over the last year and a half, report researchers from Hong Kong and China. This reassortment, they say, should serve as a warning that increased surveillance of swine is vital for minimizing consequences should a variant influenza strain emerge that poses a risk to human and animal health.
Mike Mitka. H1N1 Influenza Virus Reassorting in Pigs, Poses Unknown Risk to Human Health. JAMA. 2010;304(6):626–627. doi:10.1001/jama.2010.1056