1 Jennie H. Kwon is an assistant professor in the Division of Infectious Diseases in the Department of Medicine at the Washington University School of Medicine, St. Louis, MO, USA. j.kwon@wustl.edu.
2 William G. Powderly is a professor in the Division of Infectious Diseases in the Department of Medicine at the Washington University School of Medicine, St. Louis, MO, USA. wpowderly@wustl.edu.