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></email>, Email: pontals@yahoo.com.