Funding for this research was provided by:
Japan Agency for Medical Research and Development (JP20wm0125006)
Received: 5 February 2021
Accepted: 19 April 2021
First Online: 21 May 2021
: An informed written consent was obtained from all the patients prior to the enrollment in this study. When the patient was unconscious, the consent was obtained from his/her parent or guardian. Institutional Review Boards of Bach Mai Hospital, Hanoi, Vietnam, and Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan, had approved this study.
: Not application
: The authors declare that they have no competing interests.