1. Centers for Disease Control and Prevention, Anchorage, Alaska, USA
2. Public Health Agency of Canada, Ottawa, Ontario, CanadaCurrent affiliation: National Centre for Immunisation, Research and Surveillance, Westmead, New South Wales, Australia
3. Public Health Agency of Canada, Ottawa, Ontario, Canada
4. National Centre for Streptococcus, Edmonton, Alberta, Canada
5. Quebec Public Health Laboratory, Ste. Anne-de-Bellevue, Quebec, Canada
6. Landspitali University Hospital, Reykjavik, Iceland
7. Institution of the Chief Medical Officer, Nuuk, Greenland
8. Norwegian Institute of Public Health, Oslo, Norway
9. National Public Health Institute, Helsinki, Finland
10. National Public Health Institute, Oulu, Finland
11. Sunderby Hospital, Lulea, Sweden
12. Umea University, Umea, Sweden
13. Statens Serum Institut, Copenhagen, Denmark