Bluetongue virus risk set out for the year ahead

The latest risk assessment of bluetongue virus entering Great Britain during 2024 has been published by the Animal and Plant Health Agency (APHA) today (7 May) following an outbreak in England last year.  

Bluetongue virus is primarily transmitted by biting midges (Culicoides species) and affects cattle, sheep, and other ruminants such as goats and deer, and camelids such as llamas. The virus does not affect people or food safety.

In an updated qualitative risk assessment, APHA confirm there is a very high probability of a new introduction of bluetongue virus serotype 3 (BTV-3) into livestock in Great Britain through infected biting midges being blown over from northern Europe.  Biting midges are most active between April and November and the timing of a potential incursion will depend on the temperature and wind patterns.  

Farmers should continue to be vigilant and monitor their animals frequently, whilst making sure their livestock and land is registered with APHA and that their contact details are updated so animals can be located in the event of an outbreak. More advice can be found on gov.uk.

The impacts on susceptible animals can vary greatly depending on the species of animal and the strain of bluetongue virus – some show no symptoms while for others it can cause productivity issues such as reduced milk yield or, in the most severe cases, it can be fatal for infected animals.  

Last November, APHA and The Pirbright Institute identified the first case of the disease in Great Britain through the annual bluetongue surveillance programme. Since then, there have been 126 bluetongue cases confirmed in England across 73 premises in 4 counties, with the last case confirmed on the 8 March 2024. All cases confirmed to date have been detected through active surveillance, with the animals likely infected in late autumn. 

Due to their proximity to areas in Northern Europe, where BTV-3 is actively being transmitted by the biting midge population and wind patterns, counties along the south and east coasts of England, including Norfolk, Suffolk, Essex, Kent, and Sussex, are considered most likely to be impacted. 

Surveillance of midges continues through the use of traps across the country.  The risk of virus transmission is expected to increase as temperatures rise and with any increase of infections on the continent.  

The government is actively monitoring the situation and has been working closely with a wide range of stakeholders to review the bluetongue virus control strategy. 

The UK has world-leading biosecurity measures and capabilities. Our approach to biosecurity is internationally recognised as delivering the highest standards of protection from pests, disease and invasive non-native species. This is underpinned by world-class scientific experience and capabilities from both within the government's science base and the wider UK science and research community.

There are no authorised vaccines available for bluetongue virus serotype 3 (BTV-3) in the UK or Europe, but the government are actively engaging with vaccine manufacturers on the development of a BTV-3 vaccine for use in the UK.  

Biosecurity Minister Lord Douglas Miller said:  

“We must not be complacent to the bluetongue virus risk and the challenge this could pose to our livestock sector.  We want to ensure our control strategy is proportionate, and we will continue to work with industry to keep them briefed on the latest disease and veterinary assessments. 

“Once the risk of transmission increases, we will also be offering free bluetongue tests to keepers in high-risk counties and we are actively engaging with vaccine manufacturers on the development of a BTV-3 vaccine for use in the UK. “

Chief Veterinary Officer Dr Christine Middlemiss said: 

“Our robust surveillance systems show we have now entered the period where biting midges are more active, and we know that the likelihood of bluetongue virus entering Great Britain is increasing.  

“Despite the increase in midge 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 . 

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

David Holdsworth, Chief Executive Officer, Animal and Plant Health Agency said:    

“The Animal Plant Health Agency's world-leading scientists and vets have been working to provide evidence and modelling to government, to enable effective proactive planning and to prepare for any potential incursion and outbreak in the UK. Our field teams stand ready and will continue to work closely with farmers and animal keepers to ensure they are kept up to date and supported during any outbreak . 

 “I would encourage farmers to make sure they register their livestock and land with APHA, ensure their contact details are updated so we can locate animals in the event of an outbreak, and monitor their animals frequently for clinical signs.”

Control of the disease is likely to include the declaration of bluetongue disease Control Zones surrounding premises where infection is confirmed to restrict the long-distance movement of susceptible animals and germinal products potentially spreading disease. Moves to slaughter will be allowed. Once bluetongue is known to be circulating in the domestic midge population, culling of livestock is not an effective control measure to deal with disease. 

APHA has also enhanced the licensing application system for moving animals between disease control zones in the event of an outbreak to make it faster and more convenient for keepers to make licence applications.   

All bluetongue virus testing for suspect cases is undertaken at the UK's bluetongue virus National Reference Laboratory (NRL) at The Pirbright Institute. To support farmers to take preventative action, the government will offer free bluetongue tests to keepers in high-risk counties once the risk of bluetongue virus transmission increases. Defra and APHA will provide further details on this in due course.  

The overall risk of importing livestock infected with BTV into GB is considered to be very low. Rules on the movement of livestock from regions affected by bluetongue are already in place and farmers are reminded that animals imported from these regions must be accompanied by the relevant paperwork to clearly show they meet certain conditions designed to reduce disease risk.  

BTV is a notifiable disease. Suspicion of BTV in animals must be reported to the Animal and Plant Health Agency on 03000 200 301 in England, on 03003 038 268 in Wales and to the local Field Services Office in Scotland.  

More information about bluetongue is available on gov.uk.