Acknowledgements
We thank all survey participants: Medical University of Vienna, Vienna, Austria; Sciensano, Brussels, Belgium; National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria; University Hospital for Infectious Diseases Dr. Fran Mihaljevic´, Zagreb, Croatia; Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus; University of Cyprus, Nicosia, Cyprus; Ostrava Institute of Public Health, Ostrava, Czech Republic; National Institute for Public Health, Prague, Czech Republic; Statens Serum Institut, Copenhagen, Denmark; Health Board Laboratory of Communicable Diseases, Tallinn, Estonia; University of Helsinki and HUSLAB, Helsinki, Finland; Finnish Institute for Health and Welfare, Helsinki, Finland; Aix Marseille University, Marseille, France; Institute Pasteur, Paris, France; Institut für Virologie, Marburg, Germany; Institute of Virology, Charite - Universitätsmedizin Berlin, Berlin, Germany; Robert Koch Institute, Berlin, Germany; Department of Microbiology, Aristotle University of Thessaloniki, Thessaloniki, Greece; Hellenic Pasteur Institute, Athens, Greece; Nemzeti Népegészségügyi Központ, Budapest, Hungary; Landspitali- National University Hospital, Reykjavik, Iceland; National Virus Reference Laboratory-U.C.D., Dublin, Ireland; Istituto Superiore di Sanità, Rome, Italy; Padova University Hospital, Padova, Italy; National Institute for Infectious Diseases Lazzaro Spallanzani IRCCS, Rome, Italy; Amedeo di Savoia Hospital, Torino, Italy; Policlinico Militare “Celio” Roma, Rome, Italy; National Microbiology Reference Laboratory- Riga East University, Riga, Latvia; National Public Health Surveillance Laboratory, Vilnius, Lithuania; Laboratoire National de Santé, Dudelange, Luxembourg; Mater Dei Hospital, Malta; Norwegian Institute of Public Health, Oslo, Norway; Cantacuzino National Military-Medical Institute for Research and Development, Bucarest, Romania; Military Institute of Hygiene and Epidemiology, Pulawy, Poland; National Institute of Public Health-National Institute of Hygiene, Warsaw, Poland; National Institute of Health, Lisbon, Portugal; Public Health Authority of the Slovak Republic, Bratislava, Slovakia; University of Ljubljana, Ljubljana, Slovenia; National Laboratory for Health, Environment and Food, Ljubljana, Slovenia; Instituto de Salud Carlos III, Madrid, Spain; Hospital Clinic, Barcelona, Spain; Public Health Agency of Sweden, Solna, Sweden; National Institute for Public Health and the Environment, Bilthoven, the Netherlands; Erasmus MC, Rotterdam, the Netherlands; Public Health England, London, United Kingdom; West of Scotland Specialist Virology Centre, Glasgow, United Kingdom; Public Health Wales, Cardiff, United Kingdom. We thank Daniel Palm and Marc Struelens (ECDC) and Mariette Edema (RIVM) for reviewing the on-line survey.

Editorial note
This article was published as an e-Alert on 11 February 2020.

Conflict of interest: None declared.
Authors’ contributions: CR: survey design, online survey building, data analysis, figures, manuscript writing; EB: survey design, figures, co-writing manuscript; BH, VC, AM, MK, AP, RC, CD: survey design, co-writing manuscript; KL: survey design, data analysis, manuscript writing.