1. a Department of Clinical Sciences , Institute of Tropical Medicine , Antwerp , Belgium
2. b Department of Research Methodology in Education , University Complutense , Hospital Carlos III, Madrid , Spain
3. c Söder Hospital , Stockholm , Sweden
4. d St Stephen's Centre , Chelsea & Westminster Healthcare , London , UK
5. e Otto Wagner Spital , Wien , Austria
6. f Department of Tropical Disease , University Hospital , Antwerp , Belgium