1. Department of Medical Microbiology, Hanoi Medical University, 1 Ton That Tung Street, Hanoi, Vietnam
2. National Hospital of Tropical Diseases, 78 Giai Phong Street, Hanoi, Vietnam
3. Enteric & Food Microbiology Laboratory, ICDDR,B: International Centre for Diarrhoeal Disease Research, Bangladesh GPO Box 128, Dhaka 1000, Bangladesh
4. Department of Infectious Diseases, Hanoi Medical University, 1 Ton That Tung Street, Hanoi, Vietnam
5. Department of Medical Microbiology & Infectious Diseases, Erasmus MC, University Medical Centre Rotterdam, The Netherlands
6. Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Churchill Hospital, Old Road, Oxford OX3 7LJ, UK
7. Oxford University Clinical Research Unit Vietnam, Wellcome Trust Major Overseas Program, National Hospital of Tropical Diseases, 78 Giai Phong Road, Dong Da, Hanoi, Vietnam