Equine influenza virus: a jumping virus that races with Thoroughbred horses and greyhounds.

This research article discusses the complexities surrounding the control of the Equine Influenza Virus (EIV), an impactful respiratory disease in horses, also noting its recent interspecies jump to dogs. The author, Dr. Janet Daly, reviews different approaches to studying EIV, discusses significant outbreaks, explores the virus’s evolution and transmission, and emphasizes the importance of diverse research disciplines for managing infectious diseases.

Equine Influenza Virus (EIV)

• EIV, a significant respiratory disease in horses, was first isolated in 1956, and has two subtypes: H7N7 and H3N8, with the latter being currently active.
• Despite the availability of continuous updates for commercial vaccines, and more than 50 years since its first isolation, EIV remains a challenge to control for veterinarians, researchers, and the horse community.
• Adding to the difficulty, the virus recently made a horse-to-dog interspecies jump, thereby creating a new respiratory pathogen for dogs – the Canine Influenza Virus (CIV).

Review of EIV

• Dr. Janet Daly’s comprehensive review discusses the ongoing challenges in controlling equine influenza as well as the available tools and techniques.
• The review encompasses a range of disciplines like classical virology, epidemiology, immunology, evolutionary biology, and mathematical modeling used to study EIV over the years.
• Through comparison of EIV outbreaks in Newmarket in 2003 and Australia in 2007, the review shows both the power and limitations of epidemiological surveillance, vaccination policies, and intervention measures.
• Daly’s review discusses viral strains’ specific interferon induction responses and their impact on disease outcomes, emphasizing the innate immune response’s importance in controlling infection in influenza.

EIV Evolution and Transmission

• The review explores the evolution of EIV, charting how and when distinct lineages have appeared and their geographical distributions. However, she notes the need for complete genomic sequences for better understanding the EIV’s evolutionary dynamics.
• A significant part of the review focuses on the interspecies transmission of EIV, discussing key events that led to CIV’s isolation and the role of viral receptors in dogs’ respiratory tracts in the viral emergence.
• The review emphasizes the importance of understanding the interspecies transmission mechanisms of EIV, especially given the valuable insights they can provide into the molecular aspects that led to the recent pandemic of the human influenza virus originating in pigs.

Summary

• In conclusion, the review by Daly stimulates thoughts on past and future EIV research and the broad range of tools available to tackle the issue.
• The article highlights the importance of integrating various basic disciplines into a consistent, comprehensive framework to minimize the burden caused by infectious diseases.