Bluetongue spreads despite vaccinations

Bluetongue is back. It has survived another winter in northern Europe, and now farmers are vaccinating livestock in a race against the biting midges that carry the virus. The first cases of the disease, which affects ruminants, began to surface this month, with France so far reporting 260. Most are located along the front line of last year’s outbreaks, suggesting that the epidemic is spreading into new territory despite France’s compulsory vaccination policy. In England, voluntary vaccination has been rolled out across the country from the south-east, where bluetongue arrived last year. The vaccination “front” has now reached Yorkshire in northern England, alarmingly close to the country’s main sheep areas. The disease kills sheep but only makes cattle ill.

Sheep just outside the vaccinated zone are at high risk, being close to potential infection, but are unlikely to be vaccinated till autumn. Much depends on whether enough farmers south of the line have vaccinated their livestock to slow the spread of the virus. The number of cases to date in France, though, suggests that it may be hard to stop.

New Scientist
August 19, 2008

Original web page at New Scientist