1. Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon;
2. Division of Infectious Diseases, Center of Tropical Medicine and Travel Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands;
3. Albert Schweitzer Hospital, Lambaréné, Gabon;
4. German Center for Infection Research, Institute of Tropical Medicine, University of Tübingen and Partner site Tübingen, Tübingen, Germany