1. Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Universidad Complutense de Madrid, Madrid, Spain
2. Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
3. CIBER Enfermedades Respiratorias-CIBERES (CB06/06/0058), Madrid, Spain
4. Medicine Department, Faculty of Medicine, Universidad Complutense de Madrid, Madrid, Spain