1. Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, CT, USA
2. Department of Hematology and Oncology, Mayo Clinic, Rochester, MN, USA
3. Department of Internal Medicine, Section of Geriatrics, Yale School of Medicine, New Haven, CT, USA
4. Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
5. Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA