1. 1The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
2. 2University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam
3. 3The Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
4. 4Hung Vuong Hospital, Ho Chi Minh City, Vietnam
5. 5Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, UK
6. 6The Department of Medicine, University of Cambridge, Cambridge, UK