[Longterm virological studies in chronic diseases of the respiratory tract I (author's transl)].

A longitudinal study on the occurrence of acute viral infection of the respiratory tract in chronic respiratory diseases was carried out from the middle of July 1973 to the middle of July 1975 in a special clinic for respiratory organs. In the present publication, the general plan of the study, aspects of the selection of the "index" patients, the collection andprocessing of the materail for investigation and the documentation of the clinical symptoms of intercurrent infections of the respiratory tract on schematized diagnostic report forms are described.