1 Department of Pediatrics, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan; Chang Gung University College of Medicine, Taoyuan, Taiwan.
2 Department of Pediatrics, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan; Chang Gung University College of Medicine, Taoyuan, Taiwan; Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Electronic address: drtsai1208@gmail.com.