The equine influenza outbreak in Newmarket, England has caused a major disruption in the horse racing industry across the UK. With 174 yards being tested for the virus after cases were detected in stables in Cheshire and Newmarket, the racing community is facing its biggest shutdown since the foot and mouth outbreak in 2001. The outbreak has led to the suspension of races as veterinarians work tirelessly to contain the spread of the virus.
Veterinary Clinician Jeremy Allen is at the forefront of this battle, swabbing Polo Ponies to test for Equine Influenza. The samples are being sent to the ‘Animal Health Trust’, a leading testing lab that first confirmed the recent outbreak. The NEH, the largest and most state-of-the-art equine hospital in Europe, is playing a crucial role in providing personalized high-quality veterinary care and emergency services to horses from around the world. Their team of equine veterinary specialists, nurses, interns, and yard staff are working round the clock to offer services like MRI scans, x-rays, and arthroscopic surgeries to the affected horses.
Scientists have long been puzzled about the origins of the 1918 influenza pandemic, the deadliest in modern history. While it was initially believed to have emerged in pigs, genomic sequencing in 2005 revealed that the virus was primarily avian in origin. Recent evidence has challenged the traditional “mixing vessel” hypothesis, suggesting that horses may have played a crucial role in the transmission of the virus to humans.
A new hypothesis put forth by medical historian Martin Furmanski and virologist Pablo Murcia proposes that horses served as an intermediate host for a prepandemic avian-origin virus before 1918. This theory is supported by biological evidence showing that horses exhibit both α2,3 and α2,6 sialic acids, making them susceptible to both avian and human influenza viruses. Additionally, historical records of a large epizootic of equine influenza in North America in 1915 align with the timeline of the 1918 pandemic.
During World War I, a massive mobilization of horses in the US created ideal conditions for viruses to spread and mutate. Over two million animals were transported across the country and overseas, providing ample opportunities for the virus to adapt and reassort. The close contact between humans and horses in military camps like Camp Funston in Kansas further facilitated the transmission of the virus.
While conclusive evidence is still lacking, the historical and biological clues present a compelling case for the role of horses in the origin of the 1918 pandemic. Understanding how pandemic viruses emerge is crucial for predicting and preventing future outbreaks. The recent spread of H5N1 among dairy cattle underscores the importance of monitoring unexpected mammalian hosts like horses for influenza viruses.
In conclusion, the 1918 influenza pandemic may have had its origins in a horse stable, highlighting the complex interplay between biology, human behavior, and historical circumstances in the emergence of pandemics. By studying these factors, we can better prepare for and mitigate the impact of future outbreaks.