1. Laboratoire des Fièvres Hémorragiques Virales du Benin, 01BP 918 Cotonou, Benin
2. Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, 20359 Hamburg, Germany
3. Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, 20359 Hamburg, Germany