Bluetongue (BT) is a disease in ruminants caused by an Orbivirus that is transmitted by midges. There are at least 24 serotypes of Bluetongue virus (BTV). Wageningen Bioveterinary Research conducts research on this disease.


Infected midges naturally infect domestic and wild ruminants (for example, sheep, cattle, goats and deer) and camelids (such as the llama and alpaca) by bites during feeding. Cattle show higher and longer viraemia than sheep, but the disease is seen more frequently and more severe in sheep (depending on the serotype of BTV).

Inflammation around the mouth

The disease is characterized by inflammation of the mucus membranes around the mouth and nose, this inflammation causes the rarely seen 'blue tongue' that gives the disease its name.

Spread of Bluetongue

In Europe, the spread of Bluetongue virus was formerly associated to the presence of Culicoides imicola. In 2006 it became clear that BTV could also be spread by endemic species of Culicoides in Northern parts of Europe.

Bluetongue does not affect humans so there are no public health implications.