1. Department of Microbiology and Infection Control, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, B-1090 Brussels, Belgium
2. Pfizer Inc., New York, NY 10001, USA
3. Pfizer International Operations, F-75668 Paris, France
4. Pfizer Inc., Kirkland, QC H9J 2M5, Canada