1. Department of Epidemiology and public health, Sciensano, 1070 Brussels, Belgium
2. Department of Epidemiology and Biostatistics, Institut de Recherche Expérimentale et Clinique, Faculty of Public Health, Université Catholique de Louvain, 1200 Woluwe-Saint-Lambert, Belgium
3. Department of Public Health and Primary Care, Ghent University, 9000 Ghent, Belgium
4. Department of Laboratory Medicine, National Reference Center for Respiratory Pathogens, University Hospitals Leuven, 3000 Leuven, Belgium
5. Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, KU Leuven, 3000 Leuven, Belgium