1. School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki 852-8523, Japan
2. Department of Global Health Policy, School of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan
3. Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
4. Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK