On Feb. 8, 2023, as bird flu continues to circle the globe, a new report suggested that the highly pathogenic avian influenza (HPAI) A(H5N1) virus spread between farmed mink in Spain last October. The virus also may have been transmitted between seals in coastal New England last summer.

The events mark the first large H5N1 outbreaks potentially driven by mammal-to-mammal transmission. The outbreaks, along with the virusﾒ ongoing transmission in wild birds and poultry and increasing infections in wild mammals, have renewed concerns that H5N1, first identified in the mid-1990s, could be poised for spillover into humans.