1 Division of Infectious Diseases, Department of Medicine, National University Health System, Singapore.
2 Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
3 Infectious Diseases Translational Research Programme, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
4 Division of Dermatology, Department of Medicine, National University Health System, Singapore; and.
5 Department of Pathology, National University Health System, Singapore.