"Swine flu" strain has passed from humans to
A new study of the strain of influenza A responsible for the 2009 H1N1 pandemic—pdm09—shows that the virus has passed from humans to swine about 370 times since 2009, and subsequent circulation in swine has resulted in the evolution of pdm09 variants that then jumped from swine to humans. Alexey Markin of the U.S. Department of Agriculture-Agricultural Research Service and colleagues present these findings in the open-access journal PLOS Pathogens.
Source: eurekalert.org