1 Division of Infectious Diseases, Department of Medicine, National University Health System, Singapore, 1E Kent Ridge Rd, Singapore 119228, Singapore.
2 Department of Medicine, National University Health System, Singapore, 1E Kent Ridge Rd, Singapore 119228, Singapore.
3 Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 10 Medical Drive, Singapore 117597, Singapore.
4 Infectious Diseases Translational Research Programme, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 10 Medical Drive, Singapore 117597, Singapore.