On 15th June, in Brussels, the European Commission announced the results of a report, published the previous day by the European Food Safety Authority (EFSA), entitled "Schmallenberg" virus: Analysis of the Epidemiological Data and Assessment of Impact (EFSA Journal 2012;10(6):2768).The report, which provides an overall assessment of the impact of the infection on animal health, animal production and animal welfare of the provisionally named “Schmallenberg” virus (SBV), supports a balanced approach to SBV when considering the implementation of trade restrictions due to the virus. Although to date 3745 holdings have been reported with SBV cases (confirmed by laboratory testing across several Member States) EFSA have identified a clear decline in the number of sick animals since February 2012. In May 2012 EFSA conducted a review of a number of epidemiological reports, which stated that SBV has been detected in cattle, sheep, goats and a bison with SBV antibodies being detected in deer. These appear to be the only species affected by the disease. As a consequence EFSA confirms the initial assessment, undertaken by the European Center for Disease Control and Prevention, that it is very unlikely that SBV poses a risk to humans.

Regarding transmission of the disease, entomological studies have isolated a number of biting midges, of the Culicoides obsoletus group, infected with SBV. Currently, other than transplacental or vector borne routes, there is no evidence of any other route of transmission. For the period 2011-2012, EFSA has coordinated the collation of SBV epidemiological data in order to obtain comparable data for Europe. “The maximum proportion of reported sheep holdings with SBV confirmed was 4% per country and 7.6% per region while for cattle less than 1.3 % of holdings were reported as SBV confirmed at both country and regional level. In order to assess the impact of SBV(spatial and temporal spread, proportion of affected holding and potential projection of arthrogryposis hydranencephaly syndrome cases) three models were used. In regions with SBV confirmed holdings, assuming a high prevalence of infection and post infection immunity, impact in the 2012-2013 calving and lambing season should be low. However, assuming SBV survived the winter of 2011, the models suggest that in unaffected regions with suitable temperatures for within herd transmission by vectors and high density of susceptible species (cattle and sheep) SBV infection is likely to spread.” (EFSA Journal 2012;10(6):2768).

This report is the third produced by EFSA, in response to the Commission's request for scientific advice, and should be of major interest to all third countries following the evolution of the SBV situation in the EU as it confirms the Commission’s initial stance on SBV. “EFSA's assessment together with the outcome of the World Organisation for Animal Health's (OIE) 2012 World Assembly that took place on 20-25 May confirms the Commission's view that trade restrictions applied by third countries on imports in live ruminants and their genetic material from the EU are disproportionate and unjustified.” (MEX/12/0615) The Commission, in conjunction with Member States, is co-financing a number of scientific studies in order to gather more information about this relatively new infection. It is also planning a series of multi-lateral and bi-lateral talks with global trading partners so as to lessen the impact of SBV on trade.

“Schmallenberg Virus is a new emerging livestock disease that has been detected in Belgium, Germany, the Netherlands and the UK. It is similar to some other animal disease pathogens, such as Akabane and Shamonda viruses, which are transmitted by vectors, such as midges, mosquitoes and ticks. The virus has been associated with brief mild/moderate disease (milk drop, pyrexia, diarrhoea) in adult cattle and late abortion or birth defects in newborn cattle, sheep and goats. All the evidence currently suggests that the disease was brought into the UK from infected midges blown across the Channel.  We have seen no evidence to suggest that it was from imported livestock. We are closely tracking the disease and will continue to work with partners across Europe and the UK to develop our knowledge of the disease. Schmallenberg Virus is not a notifiable disease but farmers are asked to contact their veterinary surgeon if they encounter cases of ruminant neonates or fetuses which are stillborn, show malformations or are showing nervous disease.” (DEFRA) SBV, which was first reported in November 2011, is named after Schmallenberg, in North Rhine-Westphalia, Germany, from where the first definitive sample was derived.

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