12.12.2024

A new study published in Emerging Infectious Diseases investigates the spillover of Influenza A(H5N1) infections in horses, with a focus on findings from Mongolia. Avian influenza viruses (AIVs) of the H5N1 subtype are well-known for their high pathogenicity in birds and their potential to affect various mammalian species. Recent surveillance has revealed a concerning rise in H5N1 infections among mammals, challenging the previously held belief that these viruses primarily act as dead-end hosts outside avian populations.
The study presents evidence of H5N1 infections in horses based on serological surveys conducted between July 2021 and October 2023.
Serum samples were collected from 10 horses across 24 herds in Mongolia, demonstrating that horses are susceptible to H5N1 viruses. Some samples showed serological evidence of infection, suggesting that these infections are likely subclinical, which complicates detection efforts. Furthermore, the research highlights ecological conditions in North America that may facilitate reassortment between equine influenza virus (EIV) and H5N1. This risk is heightened by the high density of horses and the endemic presence of EIV in the region.