[Clinical characteristics in 8 sporadic cases of community-acquired Legionella pneumonia].

To study the clinical characteristics of community-acquired Legionella pneumonia, we carried out a study of 8 patients (7 men and a woman; mean age, 68.4 years) with Legionella pneumonia at Yaizu Municipal General Hospital between 1996 and 1999. We surmised that the sources of infection were travel or a hot spring, or both, in 4 cases, occupation (plumbing and fish market work) in 2 cases and gardening in one. All patients had fever above 38 degrees C, hypoxemia and a high inflammation reaction of. The initial findings of chest radiography were air-space consolidation in all cases, lobar pneumonia in 7, and unilateral shadows in 6, similar to those seen in acute Streptococcus pneumoniae pneumonia. Diagnostic methods were urinary antigen in 4 of 7 cases, bacterial culture in 4 of 6 cases (L. pneumophila, 3 cases; L. longbeachae, 1 case), polymerase chain reaction on the serum in 2 of 5 cases, and serum antibody in 1 of 7 cases. Urinary antigen was most useful for early diagnosis. The clinical presentation and the initial chest radiography findings were non-specific, despite the high fever, severe hypoxemia, and radical progression within a few days.