Necrotizing or Cavitating Pneumonia Due to Streptococcus pneumoniae

Publisher Website
Google Scholar
Abstract
S. pneumoniae is seldom considered as an etiologic agent of necrotizing or cavitating pneumonia. During a 5 mo. period 4 patients, bacteremic with S. pneumoniae, were observed with such a pulmonary process. This association may be more frequent than is commonly assumed. Anatomic, physiologic and immunologic alterations of the pulmonary defense mechanisms prior to and during the infection as well as virulence factors of S. pneumoniae (i.e., rapid multiplication, accumulation of capsular polysaccharides and inhibition of phagocytosis) in concert may produce the resultant decrease in bacterial clearance from the lung with the consequent necrosis of lung parenchyma. Since sputum and blood cultures are reported to be positive in only 50% and 25%, respectively, of cases of pneumonia, etiologic diagnosis may be difficult. S. pneumoniae must be considered in the differential diagnosis of the patient with necrotizing or cavitating pneumonia.