As in other GNB infections, the clinical presentation depends on the infected anatomic site.

• Pneumonia:Klebsiella is a common cause of pneumonia among residents of long-term care facilities and hospitalized pts. In Asia and South Africa, community-acquired pneumonia due to hypervirulent strains of K. pneumoniae is increasingly common, particularly among younger, healthy pts.
  • - The presentation is similar to that of pneumonia caused by other enteric GNB, with purulent sputum production and pulmonary infiltrates on CXR.
  • - Infection can progress to pulmonary necrosis, pleural effusion, and empyema.
• UTI:K. pneumoniae causes 1-2% of cases of uncomplicated cystitis and 5-17% of cases of complicated UTI.
• Abdominal infections:Klebsiella causes a spectrum of disease similar to that of E. coli, but with less frequent occurrence. Hypervirulent strains have become a common cause of monomicrobial community-acquired liver abscess, spontaneous bacterial peritonitis, and splenic abscess.
• Bacteremia: Bacteremia can arise from a primary infection at any site; infections of the urinary tract, respiratory tract, and abdomen (especially hepatic abscess) each account for 15-30% of episodes.
• Other infections:Klebsiella cellulitis or soft tissue infection most frequently affects devitalized tissue and immunocompromised hosts. Klebsiella can also cause endophthalmitis, nosocomial sinusitis, and osteomyelitis.