Avis scientifique sur la fièvre catarrhale ovine du groupe scientifique sur la santé et le bien-être des animaux de l'EFSA (2007−2008)

Résumé

The first outbreak of bluetongue virus serotype 8 (BTV-8) in the European Union (EU) was officially declared in the area of Maastricht on August 17, 2006. The infection spread extensively in the summer and beginning of autumn; The European Food Safety Authority (EFSA) Panel on Animal Health and Welfare (AHAW) adopted a statement on the significance of these recent outbreaks in September 2006. It expressed concerns about the appearance of vector-borne viruses never seen before in the EU and recommended: i) harmonising the collection of epide­miological data and sampling procedures [blood for antibod­ies and polymerase chain reaction (PCR) testing]; ii) monitor­ing and studying spatial and temporal patterns of potential and known vector occurrences; and iii) sharing information between Member States. Furthermore, it recommended the investigation of the routes of BTV-8 introduction in the EU. In October, EFSA was requested by the European Commission (EC) to describe the evolution of the disease during the outbreaks as well as to conduct a global epidemiological analysis. A working group, including relevant experts from the affected countries, provided a weekly overview of the epidemic and a final report containing all information and analysis.  In December 2006, the EFSA–AHAW Panel received a mandate from the EC focusing on the control of vectors and vaccines for all BT serotypes. Comprehensive analyses of the role of vectors as well as possible control measures were reviewed. The opinion identified important knowledge gaps and provided recommen­dations for future research. As part of EFSA approach, a consulta­tion meeting with the International Federation for Animal Health (IFAH) and vaccine manufacturers was held. A letter request­ing information on outbreaks of BT and vaccination campaigns against BT was sent to chief veterinary officers. All information was reviewed and the Panel concluded that vaccines were suit­able for the control of the infection in endemic/epizootic areas: vaccination, preferably using an inactivated virus, was recom­mended as a first line of defence but within a set of measures, including animal movement control and Culicoides control. The Panel also considered the option of vaccination in high risk areas of virus free countries.  BTV-8 was a wake-up call to the possibility of further emerging diseases in the EU. The Panel decided to address the origin and occurrence of BT serotypes exotic to the EU in order to obtain a better understanding of their evolution and subsequent spread, and to make recommendations as to the potential preventive measures that could be implemented in order to minimise the reoccurrence of such events in the future.  An update of previous EFSA scientific opinions on BT was con­cluded in September 2008 as regards: i) vector ecology and criteria for the determination of the seasonally free period; ii) the over-wintering mechanisms of BT virus; iii) the length of viraemia of all BTV serotypes relevant to the EU situation; iv) scientific advice on the effectiveness and suitability of insecti­cides and repellents for Culicoides species; and v) the different measures that can be used to protect animals against attacks by vectors. The work conducted by EFSA during 2007-2008 rep­resents a coordinated effort of expertise and communication without precedent in the European risk assessment community and a valuable experience on what can be done when facing emerging issues.