Abstract
A 78-year-old Japanese man was admitted to our hospital because of fever lasting for 4 days. His white blood cell count and C-reactive protein level were elevated and computed tomography of the chest showed bronchopneumonia in the right upper lobe of the lung. Streptococcus pyogenes was detected from sputum and blood culture samples on admission and administration of ampicillin/sulbactam was effective. Although our patient's clinical course was good, S. pyogenes pneumonia commonly shows a high rate of fatality and septicemia, and may affect a previously healthy population. Physicians should be aware of pernicious characteristics of S. pyogenes pneumonia.