Bacteremic Hemophilus influenzae pneumonia in the adult

Bacteremic Hemophilus influenzae pneumonia is an uncommon infection in the adult. It usually affects chronically ill patients, especially those with chronic obstructive lung disease, although healthy individuals can also be affected. The condition carries a significant mortality, reaching 57% in one series. We describe ten adult patients with bacteremic H influenzae pneumonia with some unique features: no deaths occurred, half of the involved patients were previously fit individuals, and a beta-lactamase producing strain was isolated in five out of ten patients. An interesting finding was the isolation of a beta-lactamase negative H influenza from the sputum of two patients whose blood cultures were positive for a beta-lactamase positive H influenza. The overall incidence of beta-lactamase production among bacteremic isolates was 50%--a finding with a great deal of impact on the treatment of this disease.