The recent appearance of the H5N1 bird flu in pigs does raise viral reassortment concerns. Here's what we know about this highly pathogenic avian influenza virus so far.

The sales suspension comes as human cases of dangerous H5N1 bird flu have risen across the country. The Centers for Disease Control and Prevention says there were 55 cases across seven states as of Friday. The majority of the cases are in California.

H5 bird flu, a type of avian influenza, has infected dozens of people in the U.S., and spread to seven states and Canada this year.As concern grows over whether it could lead to another pandemic or lockdown,