EHV survives for 48 hours on bedding
The research looked at the persistence of EHV-1 on a range of materials and under different environmental conditions
VIABLE equine herpes virus (EHV-1) lingered on a range of environmental materials for 48 hours, a study has found.
Researchers from the Center for Companion Animal Studies, Colorado State University, found that the virus’s persistence, on a range of materials, was likely to represent a transmission risk.
For the study, published in the Equine Veterinary Journal, the virus was applied to leather, polyester/cotton fabric, bedding materials – shavings and straw – and plastic, and left in different environmental conditions; 4°C, indoors and outdoors.
They found that although there were “significant reductions” in concentration in the first three hours, viable virus was still recovered after 48 hours.
“Barrier precautions should be used to prevent spread of EHV-1 from unrecognised environmental reservoirs,” the study concluded.
Researcher Brandy A
Burgess, an associate professor of epidemiology and infection control, and director of infection control at the University of Georgia’s veterinary teaching hospital, told H&H EHV-1 can be a challenge to manage.
“So it’s something we want to understand more about, and about how to manage it,” she said.
She added that many horses can shed the virus without showing signs, so measures to mitigate spread should help decrease the risk of outbreaks.
“Another thing to note is that this was the virus by itself,” she
said. “In nature, it would be shed in saliva or mucus, which protects it, so we’d expect it to last longer.”
Dr Burgess said materials that are fibrous or porous – so cannot be scrubbed clean and disinfected – can harbour the virus, so the message is “don’t share”.
“We shouldn’t share any tack, brushes or buckets, not just because of this but because of anything that can be spread,” she said. “You shouldn’t walk through a facility and pet other horses; you’re at a competition, not a zoo; keep your hands to yourself.”
Sealing wooden surfaces will make them easier to clean, and bedding should be changed between horses.
“What we’re trying to do is simple; to disrupt the chain of transmission,” she said.
David Rendle, chair of the British Equine Veterinary Association health and medicines committee, told H&H the study provides useful information on EHV’s ability to survive.
“But it is always difficult to extrapolate the results of studies of this type to a field setting,” he said. “The situation with EHV is further complicated by large numbers of horses carrying the virus without showing any signs of infection and acting as a reservoir for disease. Horses with signs of infection with herpes virus remain the most likely source of infection for other horses.
“But this study highlights the importance of disinfection and biosecurity in general in preventing the spread of EHV.”