1 Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Av Prof Egas Moniz, Lisbon P-1649-028, Portugal
2 Centre de Recherches Médicales de Lambaréné – CERMEL, Albert Schweitzer Hospital, Lambaréné, Gabon
3 Institut für Tropenmedizin, Universität Tübingen, Tübingen, Germany
4 Centre of Tropical Medicine and Travel Medicine, Amsterdam Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
5 Instituto de Microbiologia, Faculdade de Medicina, Lisbon, Portugal