1 Julius Center for Health Sciences (Drs Postma, van Werkhoven, and Bonten), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Internal Medicine and Infectious Diseases (Dr Oosterheert), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Medical Microbiology (Dr Bonten), University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: d.f.postma@umcutrecht.nl.
2 Julius Center for Health Sciences (Drs Postma, van Werkhoven, and Bonten), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Internal Medicine and Infectious Diseases (Dr Oosterheert), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Medical Microbiology (Dr Bonten), University Medical Center Utrecht, Utrecht, The Netherlands.