1. These authors contributed equally to this manuscript
2. European Programme for Intervention Epidemiology Training (EPIET) and European Public Health Microbiology (EUPHEM) training programme, European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
3. National Institute for Public Health and the Environment (RIVM) - Centre for Infectious disease control, Bilthoven, the Netherlands
4. Virus and Microbiological Special Diagnostics, Statens Serum Institut, Copenhagen, Denmark
5. European Centre for Disease Prevention and Control, Stockholm, Sweden
6. Department of Infectious Diseases and Centre for Global Health, University of Southern Denmark, Odense, Denmark