1. Division of Pulmonary Rehabilitation, Istituti Clinici Scientifici Maugeri IRCCS, Tradate, Italy, Department of Medicine and Surgery, Respiratory Diseases, University of Insubria, Tradate, Varese-Como
2. Servizio di Epidemiologia Clinica delle Malattie Respiratorie, Istituti Clinici Scientifici Maugeri IRCCS, Tradate, Italy
3. Clínica de Tuberculosis, Instituto Nacional de Enfermedades Respiratorias Ismael Cosio Villegas, Mexico City, Mexico
4. Department of Infectious Diseases, Galliera Hospital, Genoa, Italy, , Email: pontals@yahoo.com