1. Centre de Recherches Médicales de Lambaréné (CERMEL), Biomedicine and Social sciences, BP 242, Lambaréné, Gabon
2. Center of Tropical Medicine & Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam University Medical Centres, location AMC, University of Amsterdam, Amsterdam, The Netherlands
3. Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany