1. 1University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam;
2. 2Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam;
3. 3Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam;
4. 4Gia Dinh Hospital, Danang, Vietnam;
5. 5Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, Pennsylvania;
6. 6Centre for Tropical Medicine and Global Health, University of Oxford, Nuffield Department of Medicine Research Building, University of Oxford, Headington, Oxford, United Kingdom