1. Centre for Infectious Disease Control, (CIb), National Institute for Public Health and the Environment, RIVM, Bilthoven, the Netherlands
2. Animal Health Service (GD), Deventer, the Netherlands
3. Jeroen Bosch Hospital, ’s Hertogenbosch, The Netherlands
4. Municipal Health Service South Limburg, Sittard-Geleen, the Netherlands
5. Municipal Health Service Brabant-Southeast, Helmond, the Netherlands
6. Municipal Health Service “Hart voor Brabant”, ’s Hertogenbosch, the Netherlands