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Bluetongue

Bluetongue is a disease of animals affecting all ruminants, including sheep, cattle, deer, goats and camelids (camels, llamas, alpacas, guanaco and vicuña). It does not affect horses or pigs.

The disease is notifiable: if you suspect the disease, you must immediately notify the duty vet in your local Animal Health Veterinary Laboratories Agency (AHVLA) office.

Latest news

Defra has issued a general licence for farmers to vaccinate their animals with inactivated vaccines in areas which are outside a restricted zone for bluetongue. The licence has been issued in accordance with the Bluetongue (Amendment) Regulations 2012/1977which come into force for England on 24 August 2012, and following a risk assessment and notification of the EU Commission. The regulations transpose the vaccination requirements of the European Union Directive 2012/5/EU of 14 March 2012 which amended Council Directive 2000/75/EC.

On 5 July 2011 Great Britain was officially declared free from Bluetongue. The Lower Risk Zones for BTV8 across England, Scotland and Wales were lifted.

The key implications for GB livestock keepers are:

  • There are no further bluetongue restrictions on exporting sheep and cattle from Great Britain
  • Livestock keepers will no longer be able to vaccinate against BTV8 or any other bluetongue serotype under EU law. From 24 August 2012 vaccination with inactivated vaccines in bluetongue-free areas is permitted.
  • Current  imports controls remain for livestock entering GB from BTV zones across Europe

GB remained part of a Protection Zone for BTV8 since the first case of disease in 2007. In June 2010 GB changed its status to Lower Risk Zone for BTV8 which offered protection against the risk of disease from imported animals, and was an important step toward BTV freedom.

The last case of bluetongue in Great Britain was in 2008 and through our surveillance we  have now been able to demonstrate to the European Commission that we have had no cases for the last two years and can officially be declared free of BTV8.

Movement of livestock into GB

Bluetongue susceptible animals entering Great Britain from bluetongue zones in the EU will need to continue to meet stringent import conditions.  It is vital that livestock keepers continue to source responsibly and check the health and vaccination status of their animals. We will maintain testing of imported animals from high risk countries.

Disease situation in Europe

There have been no reports of active bluetongue circulation in Northern EU Member States and the threat of bluetongue entering GB has decreased significantly. We will continue to monitor the disease situation in Europe and the level of risk to the UK with bluetongue experts.

About Bluetongue

Bluetongue is a disease of animals affecting all ruminants, including sheep, cattle, deer, goats and camelids (camels, llamas, alpacas, guanaco and vicuña). It does not affect horses or pigs. Although sheep are most severely affected, cattle are the main mammalian reservoir of the virus and are very important in the epidemiology of the disease. It is characterised by changes to the mucous linings of the mouth and nose and the coronary band of the foot. The disease is caused by a virus spread by certain types of biting midges. Bluetongue is present when it is confirmed by laboratory tests that the Bluetongue virus (BTV) is circulating in an area. Bluetongue does not affect humans.

Cause

Bluetongue is caused by a virus within the Orbivirus genus of the family Reorvirades. At present 24 distinct serotypes have been identified as a result of serum neutralisation tests.

The virus is transmitted by a small number of species of biting midges of the genus Culicoides. Bluetongue virus cannot naturally be transmitted directly between animals. Virus transmission between animals occurs via these midges. However, the likelihood of mechanical transmission of the virus between herds/flocks and within a herd/flock by unhygienic practices (e.g. use of contaminated surgical equipment or hypodermic needles) cannot be excluded.

When a midge bites an infected animal, the virus passes to the midge in the blood meal and the virus multiples in the midge. The cycle of replication of the virus in the insect vector and in the ruminant host, results in amplification of the amount of BTV available to uninfected naive hosts and vectors. Peak populations of vector Culicoides occur in the late summer and autumn and therefore this is the time when Bluetongue is most commonly seen.

Under internationally agreed guidelines (OIE) Bluetongue is unusual in that the disease is only confirmed when there is evidence that the virus is circulating between animals and vectors in an area.

Travel distances by midges infected with bluetongue

The species of Culicoides midge which has acted as a vector for disease in the current North European outbreak, are different from the species which have traditionally acted as the vector in Southern Europe and Africa. The European Food Standard Agency are currently conducting a detailed epidemiological analysis of the North European outbreak, including details of vector biology and behaviour.

From initial studies it can be roughly estimated that a midge can travel up to 1.5 – 2 km a day in a local area. However, if caught in suitable meteorological conditions midges can be carried much farther distances, especially over water masses i.e. more than 200 km. All of these details are an approximation and vary according to local environmental, topographical and meteorological conditions.

Advice to farmers

We have a separate page which explains more about about precautions you should take, and about how to spot the disease:

Advice to the public

Bluetongue is an insect-borne viral disease which affects all ruminants, such as cattle, goats, deer, llamas, alpacas, guanaco, vicuna, camels and, in particular, sheep. Bluetongue does not affect humans. There is no risk to human health. Bluetongue does not affect dogs or horses. There are no restrictions on dog walking or horse riding, and no closure of footpaths, because of Bluetongue. There are no restrictions on personal imports/exports.

Surveillance and control

Control strategy

The Bluetongue Control Strategy has been agreed in partnership with the farming industry and Devolved Administrations and sets out how we will respond to any disease outbreak.

The measures set out in legislation are aimed at preventing disease spread through, for example, restriction of animal movement and through vector control measures. Broadly, the controls can be summarised as follows:

  • Veterinary investigation on suspect premises, and restrictions which includes a ban on movement of susceptible animals on and off the premises.
  • On confirmation that bluetongue virus is circulating, a Restricted Zone (RZ) will be declared around the infected premises. The RZ may consist of:
  • A Protection Zone (PZ) (at least 100km radius around an IP) and a Surveillance Zone (SZ) (at least 50km in radius beyond the PZ); together they are called the Bluetongue Restricted Zone.
  • There is some flexibility in demarcating the Bluetongue Zones (with Commission agreement), but various factors such as local geography must be taken into account. The size of the Bluetongue Zones in England is based on EU legislation for the control of the disease and veterinary risk assessment.

The vector-borne nature of the disease (and distribution of vectors) ensures that the risk of disease spread can only be controlled to a limited degree (i.e. we cannot guarantee 100% protection from vectors). As Bluetongue is spread via vectors (i.e. midges), rather than from animal to animal, compulsory slaughter of ruminants infected with bluetongue would not normally form part of our control strategy.

Surveillance

There is a legal requirement for livestock holders to report all cases of Bluetongue infection on their premises. This allows us to assess any new midge-transmission from the continent or re-emergence of disease.  If disease was found circulating within GB we would assess the situation and carry out additional surveillance as we did in 2009/2010. It is important that livestock keepers continue to remain vigilant and report suspicion of bluetongue as this remains a legal requirement and is a key element of our surveillance.

Legislation

Commission Regulation of 26 October 2007 (1266/2007) on the control, monitoring, surveillance and movement restrictions of certain animals susceptible to bluetongue. A fully consolidated copy of the Regulation (PDF) is available.

Key publications

Page last modified: 23 August 2012