1. World Health Organization, Geneva, Switzerland.
2. Health and Safety Laboratory, Buxton, UK.
3. Institute of Virology and Immunology, Mittelhäusern, Switzerland.
4. Public Health England, Salisbury, UK.
5. Public Health Agency of Canada, Ottawa, Canada.
6. Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand.
7. Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Churchill Hospital, Oxford, UK.
8. Centers for Disease Control and Prevention, Washington, DC, USA.