Health economics
2026-04-26
9 minute read
12 sources
H5N1 in US Dairy 2024 to 2026: A Slow-Motion Pandemic Stress Test
Two years after the first detection of H5N1 genotype B3.13 in a Texas dairy herd, the outbreak has spread to 17 states, infected at least 70 workers, killed one person, and left the United States one reassortment event away from a pandemic.
On 25 March 2024 the USDA confirmed the first detection of highly pathogenic avian influenza H5N1 in dairy cattle, in a Texas herd presenting with reduced milk production and lethargy. Two years later, the outbreak is the largest mammalian H5N1 event ever recorded. The B3.13 genotype has crossed into 17 states and roughly 1,070 herds, inf...