1. National Referral Unit for Tropical Diseases , Infectious Diseases Department, , Madrid 28034 , Spain
2. Ramón y Cajal University Hospital, IRYCIS , Infectious Diseases Department, , Madrid 28034 , Spain
3. Universidad de Alcalá , Madrid , Spain
4. CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III , Madrid , Spain
5. Division of Infectious Diseases and Travel Medicine, Mount Auburn Hospital , Cambridge, MA , USA
6. Faculty of Medicine, Harvard Medical School , Boston, MA 02115 , USA