Bacteremia in patients with cystic fibrosis.

Bacteremia in patients with cystic fibrosis (CF) has not been previously reported, a fact probably attributable to activated systemic immunity in the presence of chronic bronchopulmonary infection. We have observed two CF patients under a year of age with documented bacteremia, and a teen-aged patient with autopsy evidence of premortem bacteremia. Organisms were Staphylococcus aureus, Serratia marcescens, and Pseudomonas aeruginosa, having presumably spread from the lower respiratory tract in both patients. None of the patients had historical or laboratory evidence of immunodeficiency. The true incidence of bacteremia in CF patients is unknown, and the circumstances under which it occurs have not yet been defined.