1. Department of Medicine and Microbiology; University of Wisconsin; Madison WI USA
2. Department of Medicine; University of Alabama at Birmingham; Birmingham AL USA
3. Department of Medicine; Duke University School of Medicine; Durham NC USA
4. Department of Medicine; Mayo Clinic; Rochester MN USA
5. Department of Medicine; University of Nebraska; Lincoln NE USA
6. Department of Medicine; Tufts University; Boston MA USA
7. Department of Medicine; University of Iowa School of Medicine; Iowa City IA USA
8. Department of Medicine; Michigan University School of Medicine; Ann Arbor MI USA
9. Emory University; Atlanta GA USA
10. Department of Medicine; University of Minnesota School of Medicine; Minneapolis MN USA
11. Department of Medicine; University of Texas at San Antonio; San Antonio TX USA
12. Department of Medicine; Johns Hopkins University; Baltimore MD USA
13. Centers for Disease Control and Prevention; Atlanta GA USA