Question
To ask the Secretary of State for Environment, Food and Rural Affairs pursuant to the answer to the hon. Member for Ogmore of 27 November 2012, Official Report, column 307W, on the Schmallenberg virus, for what reasons his Department has classified Schmallenberg virus as a low impact disease.
[147580]
Answer
Schmallenberg virus (SBV) is classified as low impact by the EU. This is as a result of reports produced by the European Food Safety Authority (EFSA)
based on data collected from all affected member states (MSs). Their report of November 2012 stated that the maximum proportion of confirmed sheep herds per region in affected MSs is 6.6% and 4% for cattle herds. At the EFSA's most recent meeting in February 2013, impact assessments from other affected member states continue to conclude an overall low impact and the Commission stressed again that they consider SBV to be a low impact disease.
This concurs with our own consideration of the impact of Schmallenberg in the UK. The online sheep survey on SBV run by the Animal Health and Veterinary Laboratories Agency (AHVLA) after lambing in 2012 has shown SBV did have an impact on the losses during the lambing season of 2011-12 on the participating farms, but not a large impact when compared to normal losses on the majority of infected farms. Losses during lambing happen on most farms whether or not SBV was present or suspected. A few SBV confirmed farms (3%) or farms with malformed lambs (12%) were badly affected with large losses of lambs and ewes. However, 3% of farms without any lamb malformations and 3% of SBV negative farms also reported high losses. Likewise both SBV confirmed farms and SBV negative farms had low losses. 494 farms took part in the study, of which 76 had had SBV confirmed by testing as the cause of malformed off spring and 140 suspected due to clinical signs, that they had had SBV infection. While some farms with certain specific management practices lambing early in the season have seen much greater impacts, this is linked to them having a large proportion of their flock all at the crucial susceptible stage of pregnancy at the same time when virus has arrived in their flock. A similar effect has been seen in the Netherlands and France, which have flocks synchronising their mating periods. The vast majority of our sheep flocks are not synchronised so there is no evidence to believe that they will see similar high impacts. This is anecdotally being borne out in recent reports from AHVLA vets in the field and the contact they have with veterinary practitioners.
Cattle herds have a much more staggered mating period and calves are born all year round, thus reducing the number of cows at the critical stage of pregnancy at the same time and lessening the impact in the herd. Data from other affected member states support this.
There have been anecdotal reports of more barren ewes and cows at scanning following the last breeding period. There are many reasons for animals not to hold at mating, including the poor weather resulting in poor nutrient content in fodder, and liver fluke, both of which have been issues late in 2012. Our scanning surveillance has not detected that SBV has been the cause of this.
Following infection, animals develop immunity which is protective against further SBV infection in the subsequent year. Research into the level and duration of immunity is one of the areas of research DEFRA is funding.
I recently met with cattle and sheep industry stakeholders to discuss the current SBV situation. They concurred with the description of the impact of SBV in the UK as described here. Subsequent to the meeting, the Veterinary Medicines Directorate has issued an update on the progress of a SBV vaccine submission for provisional marketing authorisation.