1. Centre de Recherches Médicales de Lambaréné, Lambaréné BP.242, Gabon
2. Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523, Japan
3. Department of Emerging Infectious Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki 852-8523, Japan
4. Division of Biomedical Science, Institute of Medicine, University of Tsukuba, Tsukuba 305-8577, Japan
5. Vietnam Research Station, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki 852-8523, Japan
6. Department of Emerging Infectious Diseases, National Research Center for the Control and Prevention of Infectious Diseases (CCPID), Nagasaki University, Nagasaki 852-8523, Japan
7. Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, 1090 Vienna, Austria