1. aWorld Health Organization, avenue Appia 20, 1211 Geneva 27, Switzerland.
2. bUniversity of Toronto, Toronto, Canada.
3. cNational Institutes of Health (NIH), Department of Health and Human Services, Washington, United States of America (USA).
4. dIndependent health consultant (formerly with the World Health Organization), Geneva, Switzerland.
5. eGroup Health Cooperative, Seattle, USA.
6. fCentre Hospitalier de Luxembourg, Luxembourg.