[1] Natl Univ Hlth Syst, Khoo Teck Puat Natl Univ, Childrens Med Inst, Dept Paediat, 1E Kent Ridge Rd,NUHS Tower Block,Level 12, Singapore 119228, Singapore
[2] Natl Univ Singapore, Yong Loo Lin Sch Med, Dept Paediat, Singapore, Singapore
[3] Natl Univ Hlth Syst, Dept Lab Med, Singapore, Singapore
[4] Natl Univ Hlth Syst, Div Infect Dis, Singapore, Singapore
[5] Natl Univ Singapore, Yong Loo Lin Sch Med, Dept Med, Singapore, Singapore