A dairy worker in Nevada has been confirmed to be infected by a new bird flu strain found to be spreading among cows in the state last week. That strain of the H5N1 bird flu virus, called D1.1 by scientists,

A newer variant of H5N1 bird flu that recently infected dairy cattle in Nevada has a genetic change thought to help the virus infect mammals – including humans – more easily, according to a new brief from the USDA’s Animal and Plant Health Inspection Service.