Bluetongue farm virus warning for sheep and cattle as midges blown into UK

  • By Malcolm Prior and Lucy Vladev
  • BBC News Rural Affairs Team

Image source, The Pirbright Institute

Legend, Infected culicoides midges from northern Europe can infect livestock with a single bite

A new strain of an animal disease that could have a devastating impact on farmers appears set to spread across England, experts have warned.

The government has said there is a “very high probability” that the bluetongue virus will be spread more widely by infected midges from northern Europe.

There have been 126 cases on cattle and sheep farms in England. The virus does not affect people or food safety.

Farmers are calling for the rapid development of a vaccine against this strain.

Last week, a vaccine received emergency approval in the Netherlands, where more than 6,000 cases of the new strain, known as BTV-3, have been recorded.

Image source, Phil Harrison/BBC

Legend, Farmer Roger Dunn had an outbreak on his farm in late 2023

But a Department for Environment, Food and Rural Affairs (Defra) spokesperson said any vaccine must go through “full marketing authorization” in the UK before it can be released. available.

The virus can cause the loss of around 30% of a flock of sheep, although the mortality rate is lower in cattle.

The disease causes damage to the tongue and mucous membranes, swallowing problems, lameness and stiffness, affecting animal welfare and leading to reduced milk yields.

Kent farmer Roger Dunn, who runs 400 cattle and 1,200 sheep, had an outbreak of bluetongue shortly before Christmas, despite a control zone with movement restrictions already in place.

Legend, Bluetongue affects ruminants, including sheep, causing serious illness and even death.

The spread of the virus was contained on the farm through the slaughter of six cattle, for which he was compensated, and the virus did not spread to sheep. But Mr Dunn knows the impact could have been much worse.

“When you could lose 30 to 40 percent of your business, that’s a big worry,” he told the BBC.

“These are all purebred Sussex cattle, which is years and years of breeding. You could lose a lot of bloodlines because of this. You could lose your entire herd to this if it becomes a serious outbreak , so it can be quite devastating. And, with the whole movement thing and everything else, it becomes a nightmare.

He added that because his farm is in an area known for bluetongue, some buyers are “very hesitant” to buy shares from him.

Midges “everywhere”

Cattle farmer David Barton, who chairs the National Farmers’ Union (NFU) livestock board, said farmers were “keen to protect their livestock” but questions remained over the vaccine approved in the Netherlands.

He said: “As this is a brand new vaccine, there are still some unanswered questions, including how much the vaccine will cost, how it will be rolled out and what support the government can offer to roll it out quickly and efficiently. “.

Last year’s outbreak was the first in the UK since 2007. Bluetongue can affect ruminants, such as sheep, cattle, goats and deer, as well as camelids such as llamas and alpaca.

The first case of the new strain was discovered in November and since then there have been 119 cases in cattle and seven cases in sheep in Kent, Norfolk and Suffolk. The most recent case was confirmed on March 8.

Experts at the Pirbright Institute’s Virus Research Center are currently studying exactly how culicoides midges spread the disease.

Scientists at the institute raise colonies of midges to study how some types carry the virus and others don’t.

Image source, The Pirbright Institute

Legend, Dr. Marion England studies tens of thousands of midges and how they carry bluetongue.

Meanwhile, midge traps placed on 18 farms across the country each provide tens of thousands of biting insects overnight for scientists to study and act as an early warning system for the presence of midges likely to transmit the virus.

Dr Marion England, who oversees national culicoides midge surveillance, explained: “The temperature at which midges become active is lower than the temperature at which the virus can be transmitted, so knowing that midges are operational takes a bit of time. time. later, we could see transmission of bluetongue. »

But she warned that with midges “everywhere” it would be difficult to control the spread of the virus.

Dr England told the BBC: “It only takes one midge bite to transmit the virus, so an infected midge can bite an animal once and that animal will have a fully developed infection.”

Dr Carrie Batten, head of the national bluetongue reference laboratory, warned farmers to be “vigilant” and monitor their livestock for any clinical signs to help the institute detect an outbreak as quickly as possible. as soon as possible and to take the necessary measures.

“As it is an insect-borne disease, it is very easy to increase the number of positive animals in the field,” Dr Batten said.

She added that the laboratory was already looking to scale up its response to be able to test around 2,000 agricultural samples per day and provide farmers with their results within 24 hours.

News Source :
Gn Health

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