[1] Natl Vet Inst SVA, Dept Epidemiol & Dis Control, Swedish Zoonosis Ctr, S-75189 Uppsala, Sweden
[2] Cent Vet Inst, Dept Epidemiol Crisis Org & Diagnost, Lelystad, Netherlands
[3] French Agcy Food Environm & Occupat Hlth & Safety, Direct Labs, Unit Coordinat & Support Surveillance, Lyon, France
[4] Tech Univ Denmark, DTU Natl Vet Inst DTU VET, Bulowsvej 27, DK-1870 Frederiksberg C, Denmark
[5] Royal Vet Coll, Vet Epidemiol Econ & Publ Hlth Grp, Hawkshead Lane, N Mymms AL9 7TA, Herts, England