1. Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Hamburg, Germany
2. University of Liège, Faculty of Veterinary Medicine, Department of Veterinary Pathology, Liège, Belgium
3. German Centre for Infection Research (DZIF), Hamburg-Luebeck-Borstel, Hamburg, Germany