Federal health officials say a dairy worker in Nevada has been infected with a new type of bird flu that’s different from the version that has been spreading in U.S. herds since last year.

The newer variant of avian influenza that recently infected dairy cattle in Nevada has a genetic change that’s thought to help the virus copy itself in mammals — including humans — more easily, according to a new technical brief from the US Department of Agriculture’s Animal and Plant Health Inspection Service.

A dairy worker in Nevada is the state’s first human case of bird flu after the employee was exposed to infected dairy cattle. In a release Monday, the Central Nevada Health District