1. Norwegian Scientific Committee for Food Safety, NO-0403 Oslo, Norway.
2. Department of Oral Biology, Faculty of Dentistry, University of Oslo, Blindern 0316 Oslo, Norway.
3. Division of Infectious Disease Control, Norwegian Institute of Public Health, Nydalen, NO-0403 Oslo, Norway.
4. National Institute of Nutrition and Seafood Research, Nordnes, No-5817 Bergen, Norway.
5. Norwegian Food Research Institute, Osloveien 1, No-1430 Ås, Norway.
6. The Norwegian Zoonosis Centre, National Veterinary Institute, Dep. No - 0033 Oslo, Norway.