Author information: (1)Unit of Population Epidemiology, Division of Primary Care Medicine, Geneva University Hospitals, Geneva, Switzerland. silvia.stringhini@hcuge.ch. (2)Department of Health and Community Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland. silvia.stringhini@hcuge.ch. (3)University Center for General Medicine and Public Health, University of Lausanne, Geneva, Switzerland. silvia.stringhini@hcuge.ch. (4)Unit of Population Epidemiology, Division of Primary Care Medicine, Geneva University Hospitals, Geneva, Switzerland. (5)University Center for General Medicine and Public Health, University of Lausanne, Geneva, Switzerland. (6)Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. (7)Institute of Global Health, Faculty of Medicine, University of Geneva, Geneva, Switzerland. (8)Division of Laboratory Medicine, Geneva University Hospitals, Geneva, Switzerland. (9)Department of Health and Community Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland. (10)Department of Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland. (11)Hirslanden Clinique des Grangettes and Hirslanden Clinique La Colline, Geneva, Switzerland. (12)School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland. (13)Infection Control Program and World Health Organization Collaborating Center on Patient Safety, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland. (14)Division and Department of Primary Care Medicine, Geneva University Hospitals, Geneva, Switzerland. (15)Division of Internal Medicine, Hôpital de la Tour and Faculty of Medicine, Geneva, Switzerland. (16)Geneva Center for Emerging Viral Diseases and Laboratory Virology, Geneva University Hospitals, Geneva, Switzerland.