Bluetongue disease (BT) is a viral, in most cases acute disease of sheep and cattle. Goats, South American camelids (e.g. llamas, alpacas) are also susceptible to BT. The virus is not transmitted directly between animals, but by small blood-sucking biting midges of the genus Culicoides. The causative agent of bluetongue disease represents no danger for humans.
Germany, which was affected from Bluetongue disease from 2006 to 2009, has been officially free from this animal disease since 2011.
More information on Bluetongue disease can be found in the respective FLI information (download right column of this webpage).
For updated information on the BT outbreak situation since 1 May 2017 please refer to the table and map on the German version of this webpage.
Since 2014, Bluetongue disease, serotype 4 (BTV-4) has spread from Greece across the Balkan states in a northwestern direction. In late 2015/early 2016, cases of the disease were detected in Austria. In 2016, mainly Italy, Slovenia, Croatia, and Serbia were affected. Some of the cases in Northern Italy, where the disease mainly affected cattle and sheep but also individual goat and mouflon holdings, were detected less than 150 km away from the German border. In June 2017, six BTV-4 outbreaks and two BTV-1 outbreaks were reported in Italy.
In France, Bluetongue disease, serotype 8 (BTV-8) has been circulating since August 2015. In autumn 2016, the number of reported BT cases increased further and the affected area expanded. BTV-8 in France is still detectable less than 150 km away from the German border and thus continues to represent a threat for Germany.
Based on past experiences it must be expected that the number of cases will re-increase over the next few months, although currently the number of outbreaks is low. The next few months (in particular August, September and October) will show how the situation in France and Italy will develop.
Table 1: Outbreaks bluetongue disease in 2017
(Source: ADNS, last updated: 28.06.2017–09:15 h)
Consequences for Germany
Although the current BTV-8 and BTV-4 epidemics are characterized by only mild symptoms of disease, clinical surveillance is important for early detection. The following symptoms are possible: fever, inflammation of mucous membranes, ulcers and necroses of the skin and oral mucosa, lips, nose, teats and udder, edema of the head and extremities as well as respiratory disorders. When any of these symptoms are observed, animal holders should contact their veterinarian without delay.
As Bluetongue disease has moved closer to Germany and can lead to severe disease and death particularly in sheep and goats, immunization of susceptible animals against BTV-8 and BTV-4 is recommended. Some federal states subsidize vaccination against Bluetongue disease.
The Standing Committee on Vaccination in Veterinary Medicine has issued a vaccination recommendation on Feb. 2, 2016.
Since 2014, Bluetongue disease, serotype 4 (BTV-4) has spread from Greece to the Balkans towards the Northwest. In late 2015 and early 2016 cases were detected in Austria. So far, in 2016 mainly Italy, Slovenia, Croatia, and Serbia have been affected. Some of the cases in Northern Italy, which affected mainly cattle and sheep, but also individual goat and mouflon holdings, are only less than 150 km away from the German border.
In France, Bluetongue disease serotype 8 (BTV-8) has been circulating since August 2015. In autumn 2016, the number of reported BT cases increased again strongly and the affected area expanded. Meanwhile some of the reported cases are only 150 km away from the German border (see map).
Consequences for Germany
Although the current epidemics of BTV-8 and BTV-4 go along with less severe symptoms of disease, clinical surveillance is important for early detection. The following symptoms are possible: fever, mucosal inflammation, ulcers and necrosis of the skin and oral mucosa, lips, nose, teats and udder, edema of the head and extremities and respiratory dysfunction. If animal holders observe any of these symptoms, they should contact their veterinarian without delay.
As Bluetongue disease has spread further towards Germany and the animal disease can lead to severe illness and death, particularly in sheep and goats, animal holders should vaccinate susceptible animals against BTV-8 and BTV-4. In some federal states vaccination against Bluetongue disease is subsidized.
The Standing Committee on Vaccination in Veterinary Medicine has issued a vaccination recommendation on February 2, 2016. (in German language only)
Risk Assessment on the Introduction of Bluetongue Disease, Serotype 4, last updated November 2015
In addition to recent developments in the spread of BTV serotype 4, the updated qualitative risk assessment on the introduction of bluetongue disease also includes serotype 8 outbreaks in France. Furthermore, the FLI has published recommendations for an increased surveillance of bluetongue disease.
Bluetongue virus (BT) of the serotype 4 (BTV4) currently circulating in Southeastern Europe continues to spread northwards, however more slowly than in the previous year. Since September 2014, Hungary has been reporting cases of BT caused by the same virus strain that is circulating in Greece and Romania. In November 2015, BT was detected in Austria, for the first time in the last seven years. The virus also belongs to serotype 4. A BT outbreak has also been reported from Slovenia in close vicinity to the Austrian border. Currently (30 November 2015) the 150 km restriction zones end at a distance of 80 km from the German border (one year ago the distance was still 400 km). In addition, BTV-4 infections have been detected in particular in Italy; the virus type however is not identical with the one circulating in the Balkan states.
In September 2015, BTV-8 re-occurred in Central France for the first time since 2010 and spread over a large area. To date, 90 outbreaks have been reported. The restriction zones end at a distance of approx. 100 km from the German border (30 November 2015).
There is a risk of introduction for BTV-4 and BTV-8 into Germany
- by the wind-borne spread of infected live vectors,
- by introduction of infected vectors through trade and traffic and
- by trade with susceptible animals, sperm, embryos and egg cells
Due to the rapid spread of the virus in Southeastern Europe the risk of introduction by live vectors in the upcoming biting midge season is assessed as likely to high.
In the exposure estimation the risk of introduction by live vectors is assessed as high, for all other introduction routes as low.
The consequence estimation shows a high risk, as both BTV-4 and BTV-8 hit an unprotected population and cause severe economic damages and considerable suffering to animals.
In addition to the legally required measures, vaccination is an option. However a vaccination programme can cause considerable costs and is only suitable to prevent a spread of bluetongue disease if vaccination coverage is adequately high.
Information on the current animal disease situation can be found in the respective latest issue of the monthly newsletter Radar Bulletin (in German language).