Control of bluetongue in Europe.

Since 1998, bluetongue virus (BTV) serotypes 1, 2, 4, 6, 8, 9, 11 and 16 have spread throughout Europe. In 2006, BTV serotype 8 (BTV-8) emerged unexpectedly in northern Europe throughout a region including Belgium, France, Germany, Luxembourg and the Netherlands. In the following year, it spread rapidly throughout the rest of Europe. In 2008, two more BTV serotypes were detected in northern Europe: BTV-6 in the Netherlands and Germany and BTV-11 in Belgium. The European incursion of BTV has caused considerable economic losses, comprising not only direct losses from mortality and reduced production but also indirect losses because of ensuing bans on trade of ruminants between BTV-infected and non-infected areas. Given the significance of the disease, all affected countries have established control and eradication measures, which have evolved with the availability of detection and prevention tools such as vaccines. Before 2005, BTV vaccination campaigns in affected countries used only modified live virus vaccines and only sheep were vaccinated, except in Italy, where all susceptible domestic ruminant species were included. After 2005, inactivated vaccines became available and cattle and goats were included in the vaccination campaigns. This review looks at how bluetongue disease has evolved in Europe and how effective vaccination strategies have been.