Replication of avian influenza viruses in equine tracheal epithelium but not in horses

Abstract

We evaluated a hypothesis that horses are susceptible to avian influenza viruses by in vitro testing, using explanted equine tracheal epithelial cultures, and in vivo testing by aerosol inoculation of ponies. Results showed that several subtypes of avian influenza viruses detectably replicated in vitro. Three viruses with high in vitro replication competence were administered to ponies. None of the three demonstrably replicated or caused disease signs in ponies. While these results do not exhaustively test our hypothesis, they do highlight that the tracheal explant culture system is a poor predictor of in vivo infectivity.

Equine Influenza

“…Other subtypes of low-pathogenicity AIV can replicate in explanted equine trachea but were similarly undetectable when experimentally administered into horses (Chambers et al 2013). However, highly pathogenic H5N1 AIV was isolated from moderately diseased donkeys in Egypt (Abdel-Moneim et al 2010), and a similar unconfirmed report came from Pakistan (A Khan, King Edward Medical University, Lahore, pers.…”