1. Department of Clinical Epidemiology, Aarhus University Hospital , Aarhus , Denmark
2. Department of Clinical Microbiology, Aalborg University Hospital , Aalborg , Denmark
3. School of Medicine, Oregon Health and Science University , Portland, Oregon , USA
4. Department of Dermatology, Aarhus University Hospital , Aarhus , Denmark
5. Department of Epidemiology, Rollins School of Public Health, Emory University , Atlanta , Georgia USA