IDPH: State unaffected by H5N1 bird flu in dairy cows Oct 6, 2025 | Population Health, Top Stories Federal officials have deemed Illinois “unaffected” by the H5N1 strain of bird flu in dairy cattle, the Department of Public Health said Friday.To access this content, you must purchase 1 Year Health News Illinois Subscription or 1 Year Group Subscription - Up to 5 Users, or log in if you are a member.