1. National Food Institute, Technical University of Denmark, Lyngby, Denmark.
2. Laboratory of Zoonoses and Environmental Microbiology, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
3. Epidemiology and Surveillance Unit, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
4. Enteric Disease Epidemiology Branch, Division of Foodborne, Bacterial, and Mycotic Diseases, National Center for Zoonotic, Vectorborne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia.
5. Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.