1 1Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, Pathology West, Westmead Hospital, Westmead 2Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Westmead Hospital, Westmead 3Centre for Research Excellence in Critical Infections, University of Sydney, Westmead Hospital, Westmead, NSW, Australia.