The CDC has confirmed 71 human cases of H5N1 avian influenza in the United States as of early 2026, with 2 fatalities. This is the largest cluster of human H5N1 cases ever recorded in the country.
The dairy farm angle
Unlike historical H5N1 outbreaks which primarily affected poultry workers, the 2026 US cluster has emerged from dairy farms. The virus appears to have established itself in cattle herds, with workers contracting it through direct contact with infected animals.
Why this is concerning
H5N1 historically has a very high case fatality ratio — around 50-60% globally since 2003. The current US outbreak shows a much lower CFR of under 3%, which suggests either the strain is less virulent or detection is catching milder cases.
What virologists are watching
The key question is sustained human-to-human transmission. So far, all confirmed cases trace back to direct animal contact. If a single case appears in someone with no animal exposure, that changes the calculus significantly.
The dairy products question
Pasteurization effectively destroys H5N1 in milk. Pasteurized commercial dairy products remain safe. Raw milk from infected herds has detectable viral RNA but no confirmed infectious virus has been recovered from properly processed dairy.
Personal risk for non-farmers
If you don't work with cattle or poultry, your individual risk is negligible. The virus does not currently spread between people. Continue with normal hygiene practices and consume only pasteurized dairy products.
Stay informed via our H5N1 disease page.