1. Division of General Internal Medicine, Department of Internal Medicine, University of Iowa Hospitals and Clinics , Iowa City, Iowa , USA
2. Division of Infectious Diseases, Department of Internal Medicine, University of Iowa Hospitals and Clinics , Iowa City, Iowa , USA
3. Department of Otolaryngology—Head and Neck Surgery, University of Iowa Hospitals & Clinics , Iowa City, Iowa , USA
4. Department of Pathology, University of Iowa Hospitals and Clinics , Iowa City, Iowa , USA