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