1 Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228; Khoo Teck Puat-National University Children's Medical Institute, National University Health System, Singapore.
2 Research Strategy & New Projects, National University Health System, Singapore.
3 Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228; University Medicine Cluster, National University Hospital, Singapore.
4 Division of Infectious Diseases, Infection Prevention and Hospital Epidemiology, National University Hospital, Singapore.
5 Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228; Khoo Teck Puat-National University Children's Medical Institute, National University Health System, Singapore. Electronic address: swee_chye_quek@nuhs.edu.sg.