Urgent bluetongue virus warning: Millions of farm animals at risk of deadly disease brought to Britain from Europe by mosquitoes

By William On May 7, 2024

Government experts have issued an urgent warning about a deadly disease that could kill millions of farm animals in Britain.

Bluetongue disease – caused by a virus spread by flying insects called mosquitoes – mainly affects sheep and cattle, but also goats, deer and even camels.

Infected animals may develop swelling of the tongue (‘bluetongue’), which can cause breathing difficulties, but other symptoms include lesions and runny nose.

Bluetongue disease was first reported in Britain in 2007, but now the government says there is a ‘very high chance’ of a new strain of the virus, called BTV-3, spreading across Britain.

There have already been confirmed cases of BTV-3 in sheep and cattle in Kent, Norfolk and Suffolk.

Bluetongue disease mainly affects sheep and cattle, but also other ruminants such as deer and goats and even camels. Experts in France treat infected sheep in 2008

What is bluetongue disease?

Bluetongue disease is an insect-borne viral disease of ruminants – mainly sheep and less commonly cattle, goats, buffalo, deer and even camels, but not horses or pigs.

Affected animals may have swelling of the tongue (‘bluetongue’), which can cause breathing difficulties.

Other symptoms include fever, lesions, redness of the mouth, eyes, nose, redness of the skin over the hoof, excessive salivation and runny nose.

The disease is caused by the bluetongue virus, which is mainly spread by biting mosquitoes.

Source: NFU/WOAH

Bluetongue does not pose a threat to human health or food safety.

Instead, the danger is the threat to livestock that could be slaughtered in places where the infection has been confirmed.

In a statement, the government said the new strain is likely to infect more British farm animals due to the transfer of infected biting mosquitoes from northern Europe.

These biting mosquitoes are most active between April and November, but a potential ‘invasion’ of the flying insects will depend on temperature and wind patterns.

Because mosquitoes thrive in warmer temperatures, the risk of virus transmission is expected to increase in warmer weather.

Counties along the south and east coasts of England, including Norfolk, Suffolk, Essex, Kent and Sussex, are most likely to be affected.

“Our robust surveillance systems show that we have now entered the period when biting mosquitoes are more active,” said Chief Veterinary Officer Dr. Christine Middlemiss.

‘We know that the risk of the bluetongue virus entering Britain is increasing.

‘Despite the increase in mosquito activity, the current risk of transmission has not changed, but I would urge farmers to remain vigilant and report any suspicions to the Animal Plant Health Agency.’

In addition to a swollen tongue, symptoms in cattle and sheep include eye and nasal discharge, lesions and redness, drooling due to mouth ulcers, swelling of the head and neck, and lameness.

Bluetongue disease is caused by a virus spread by flying insects called mosquitoes. Pictured: an electron micrograph of the bluetongue virus

In addition to a swollen tongue, symptoms in cattle and sheep include eye and nasal discharge (pictured in a sheep), lesions and redness, drooling due to mouth ulcers, swelling of the head and neck, and lameness.

The severity of the disease varies between species, but symptoms are usually most severe in sheep, leading to death, weight loss and disruption of wool growth.

Cattle (cows and bulls) often have a higher infection rate than sheep and affected cows may suffer lower milk yields even if they survive.

The government says there have been 126 confirmed cases of bluetongue in England: 119 in cattle and seven in sheep.

There are no authorized vaccines available for BTV-3 in the UK or Europe.

However, the government is ‘actively engaging’ with vaccine manufacturers over the development of a BTV-3 vaccine for use in Britain.

According to the government, the overall risk of importing cattle infected with the bluetongue virus to Britain is considered ‘very low’.

However, rules already exist for the movement of livestock from regions affected by bluetongue

Sheep show clear clinical signs of bluetongue more often than cattle when infected with the bluetongue virus

“We should not be complacent about the risk of bluetongue virus and the challenge it could pose to our livestock sector,” Biosafety Secretary Lord Douglas Miller said.

‘We want to ensure that our control strategy is proportionate, and we will continue to work with industry to keep them up to date with the latest disease and veterinary assessments.

‘As the risk of transmission increases, we will also offer free bluetongue testing to holders in high-risk areas and are actively discussing the development of a BTV-3 vaccine for use in Britain with vaccine manufacturers.’

The public can read more about bluetongue disease at the government website.

Bluetongue: The viral disease is spread by biting insects

Bluetongue disease is an insect-borne viral disease of ruminants – mainly sheep and less commonly cattle, goats, buffalo, deer and even camels.

Here, the Center for Food Security and Public Health answers the public’s and farmers’ most important questions about the disease.

WHAT IS BLUETONG AND WHAT CAUSES IT?

Bluetongue is a non-contagious, viral disease spread by biting insects. It affects ruminant species, especially sheep.

Bluetongue causes many different symptoms in affected animals, including sores, sores, sore hooves, lameness and reproductive problems.

Affected animals may have swelling of the tongue (‘bluetongue’), which can cause breathing difficulties.

The disease occurs worldwide. In the US, the disease occurs in the southern and western states.

WHICH ANIMALS GET BLUETONG?

The bluetongue virus affects many domestic and wild ruminants.

The disease is most commonly seen in sheep, sometimes in goats and rarely in cattle. Serious diseases can also occur in wild ruminants, such as white-tailed deer, pronghorns and desert bighorn sheep.

HOW CAN AN ANIMAL GET BLUETONG?

The virus is transmitted by mosquitoes, including the species Culicoides imicola and Culicoides variipennis.

Other biting insects, such as ticks or sheep squirrels, can also transmit the virus.

Bluetongue is not contagious and is not spread through contact between animals.

However, the virus can be spread by contaminated objects (fomites), such as surgical equipment and needles.

The bluetongue virus can be transmitted from the mother to the fetus during pregnancy. The virus can be found in semen, but sexual transmission does not appear to be a major route of infection.