1 Department of Infectious Diseases and Clinical Microbiology, Aarhus University Hospital Skejby, Aarhus, Denmark. Electronic address: eskildp@dadlnet.dk.
2 Division of Respiratory Medicine and Stanley Ho Center for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, China. Electronic address: dschui@cuhk.edu.hk.
3 Departments of Microbiology and Pediatrics, University of Iowa, Iowa City, IA, USA.
4 Division of Infection and Immunity, University College London, and NIHR Biomedical Research Centre, UCL Hospitals NHS Foundation Trust, London, United Kingdom. Electronic address: a.zumla@ucl.ac.uk.