Risk of Bluetongue spreading to the UK highest in September

The risk of Bluetongue spreading to the UK is highest this month, September, and at the moment the Department of the Environment, Food and Rural Affairs (DEFRA) has no reason to change this risk level.

Eight new outbreaks have been reported since July 21 in France, bringing the total number of outbreaks to 297.

All of the cases were detected as part of active surveillance, and all were in cattle where just one or two animals tested positive out of a sample size of 60/farm.

The extent of the restriction zones have not changed as a result of these cases and have been the same since April 2016.

The size of any outbreak in UK would depend on the immune status of the livestock in the area around the first case or where infected midges are blown in, according to DEFRA.

Earlier this year, bulk milk testing of a limited number of herds in the South and South East of England showed a high proportion of positive herds.

However, follow-up of a proportion of these herds showed this positive status was only reflected in a small proportion of the animals present in the herd which had previously been vaccinated and therefore should not be taken as herd level protection.

Vaccination of the whole herd is the only means to successfully prevent an outbreak. Partial herd immunity (when only a proportion of herds in a region are protected) may only serve to reduce the size of the outbreak.

DEFRA’s risk level remains the same , at medium, for this time of year and it has not increased the risk level to high as there are no reports of disease from either northern France or other countries in northwest Europe.

There is still some uncertainty around the intensity of circulating virus in France, but it has not caused significant clinical disease in regions where the pathogen is present.

DEFRA will continue to monitor the current situation in France and report any further updates from the French Authorities.

BTV-8 vaccine has been available for the British market since mid-July, and the decision to vaccinate should be taken by the farmer, in consultation with their private veterinary surgeon.