Avian Influenza Outbreak Spreads to Mammals on Illinois Farm

A highly pathogenic avian influenza outbreak that decimated a backyard flock in Illinois has spread to a domestic cat and wild rats, according to analysis by the University of Illinois and the University of Missouri. Researchers confirmed the mammals were infected with the same H5N1 subtype found in the poultry, likely through scavenging carcasses.

Viral genomic sequencing revealed nearly identical sequences across all three species, with mammalian-adaptation mutations detected in the samples. Experts suggest that wild rats, which live close to livestock and feed, may serve as an overlooked link in virus transmission between wild birds and domestic environments.

Editor's note: The brief effectively summarizes the key findings of the H5N1 transmission study, including the specific animal hosts and the significance of the genomic findings.