LEGIONELLA SPECIES COMMUNITY-ACQUIRED PNEUMONIA - A REVIEW OF 56 HOSPITALIZED ADULT PATIENTS

Background: In a prospective study, Legionella species (Lsp) was ident ified as the causative agent in 56 (16.2%) of 346 adult patients hospi talized over the course of 1 year with community-acquired pneumonia (C AP), in the Soroka Medical Center, Beer-Sheva, Israel. Objective: To c haracterize patients with Lsp CAP in our study. Methods: The diagnosis of infection with Lsp was based on serologic testing of antibodies us ing the indirect immunofluorescent method. Results: In 35 (62.5%) of t he patients, at least one other etiologic agent for CAP was identified in addition to Lsp. The patient population was relatively young, with relatively low rates of chronic comorbidity, and a broad spectrum of disease severity compared with previously published studies, No single epidemiologic, clinical, laboratory, or radiographic characteristic d ifferentiated between Lsp CAP and other CAP patients in our study, Thr ee patients (5.4%) who were not treated with erythromycin died, Howeve r, in contrast, nine patients who were treated with beta-lactam antibi otics recovered completely. Conclusions: Lsp is a common cause of CAP in our region, usually as a coinfection with another causative agent, Lsp CAP, which cannot be characterized on the basis of clinical, routi ne laboratory, or radiographic data, requires specific microbiologic o r serologic diagnosis. Treatment with erythromycin appears to be impor tant to reduce mortality from this disease, but in a significant numbe r of patients, the disease may be self-limited.