1. Department of Pathology and Pathogen Biology, Centre for Emerging, Endemic and Exotic Diseases, Royal Veterinary College, University of London, Hatfield AL9 7TA, UK
2. Communicable Diseases Policy Research Group, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
3. Faculty of Public Health, Mahidol University, 420/1 Rajavithi Road, Bangkok 10400, Thailand