1. Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Hamburg, Germany
2. German Centre for Infection Research (DZIF), partner site Hamburg-Luebeck-Borstel, Hamburg, Germany
3. Public Health Authority Steglitz-Zehlendorf, Berlin, Germany
4. State Office of Health and Social Affairs, Berlin, Germany
5. Robert Koch Institute, Department for Infectious Disease Epidemiology, Division of Gastrointestinal Infections, Zoonoses and Tropical Infections, Berlin, Germany