1. Department of Infectious Diseases, Hospital Universitario Ramón y Cajal, IRYCIS, Carretera de Colmenar Viejo, Km 9.100, 28034 Madrid, Spain
2. CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029 Madrid, Spain
3. Department of Medicine, University of Alcalá, 28801 Alcalá de Henares, Spain
4. CIBER of Epidemiology and Public Health (CIBERESP), 28029 Madrid, Spain
5. Department of Microbiology, Hospital Universitario Ramón y Cajal, IRYCIS, 28034 Madrid, Spain
6. Department of Gastroenterology, Hospital Universitario Ramón y Cajal, IRYCIS, 28034 Madrid, Spain
7. Centro de Salud García Noblejas, 28037 Madrid, Spain
8. Centro de Salud Mar Báltico, 28033 Madrid, Spain
9. Centro de Salud Cirajas, 28017 Madrid, Spain