1 Departments of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. Electronic address: npermpa1@jhmi.edu.
2 Department of Hematology, Universitaire Ziekenhuizen Leuven, Leuven, Belgium.
3 Departments of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.