ABSTRACT
The pathogens which cause community-acquired pneumonia (CAP) are the same in normal hosts as in nonneutropenic cancer patients. Most cases are caused by Streptococcus pneumoniae, Hemophilus influenza or Moraxella catteralis; and to a lesser extent by Mycoplasma pneumoniae, Legionella pneumophila, or Chlamydia pneumoniae. Staphylococcal pneumonia is uncommon in both normal hosts and in cancer patients and when present usually follows viral pneumonia such as influenza. In a normal host, polymicrobial pneumonia is rare, except for aspiration pneumonia. In cancer patients with pneumonia, isolation of more than one pathogen is frequent. Immunosuppressed patients have higher rates of oropharyngeal colonization by enteric gram-negative bacilli. Bacteremia from pneumonia is a relatively early manifestation of CAP and is not a poor prognostic indicator [1-6].
