Affiliation: | Nagasaki University, Nagasaki, Japan (F. Hasebe, S. Inoue, F. Yu, K. Morita);;National Institute of Hygiene and Epidemiology, Hanoi, Vietnam (N.T.T. Thuy, L.T.Q. Mai);;National Institute of Infectious Diseases, Tokyo, Japan (Y. Kaku); University of Tokyo, Tokyo (S. Watanabe, H. Akashi);;Tay Nguyen Institute of Hygiene and Epidemiology, Dak Lak, Vietnam (D.T. Dat) |