[Legionnaires' disease in the Lake Zurich area. Report on 6 sporadic cases].

Six sporadic cases of Legionnaires' disease seen over 13 months in the region of Lake Zurich (Switzerland) are reported. The disease was severe in all cases; 2 patients died while on artificial respiration; 5 patients were heavy smokers; 3 had probably acquired the infection in France. These 6 patients showed the following typical symptoms and signs: fever above 39 degrees C (6 patients), nonproductive cough (4), gastrointestinal symptoms (4), encephalopathy (4), renal insufficiency (5), hepatic involvement (4), bilateral pneumonia (4), and pO2 below 60 mm Hg (4). The disease was diagnosed serologically in all cases and by staining and culturing Legionella pneumophila from lung tissue in one case. The authors propose to treat unusual cases of pneumonia with erythromycin from the outset.