[Clinical data on Legionnaires' disease. Report on 8 sporadic cases of Legionella pneumonia].

In 1978 and 1979, eight sporadic cases of Legionella pneumonia were observed in the Berne and Ticino areas of Switzerland. In all cases the diagnosis was established serologically using indirect immunofluorescence. Seroconversion was observed in five patients. In three cases initially high antibody titers decreased progressively. The clinical picture was characterized by acute onset with high fever, frequent chills, and dry cough. Occasional concomitant symptoms included muscular pains, headache, thoracic pain, dyspnea, hemoptysis, and gastrointestinal and central nervous symptoms. Laboratory findings showed markedly increased BSR as well as slightly increased WBC with a pronounced shift to the left. In all cases, X-ray examinations demonstrated extended, mainly unilateral and often remarkedly peripheral infiltrations of the lung. On the basis of the clinical course, two groups could be distinguished: (a) non-complicated cases of pneumonia with rapid improvement within 2-3 weeks; and (b) cases with a protracted sometimes severe course with persistence of the infiltrations up to 4 months and more. All patients with a protracted course suffered from concomitant symptoms. Whereas none of the patients died of legionellosis, two patients died six months later from their underlying disease. Most patients were treated with several antibiotics. In three patients definite improvement occurred only after therapy had been changed to doxycycline. Erythromycin, currently recommended as the drug of choice, was used in none of these cases.