Acute Klebsiella pneumoniae pneumonia alone and with concurrent infection: comparison of clinical and thin-section CT findings

Abstract

The purpose of this study was to identify the clinical and thin-section CT findings in patients with acute Klebsiella pneumoniae pneumonia (KPP) alone and with concurrent infection. We retrospectively identified 160 patients with acute KPP who underwent chest thin-section CT examinations between August 1998 and August 2008 at our institution. The study group comprised 80 patients (54 male, 26 female; age range 18-97 years, mean age 61.5) with acute KPP alone, 55 (43 male, 12 female; age range 46-92 years, mean age 76.0) with KPP combined with methicillin-resistant Staphylococcus aureus (MRSA) and 25 (23 male, 2 female; age range 56-91 years, mean age 72.7) with KPP combined with Pseudomonas aeruginosa (PA). Underlying diseases in patients with each type of pneumonia were assessed. Parenchymal abnormalities were evaluated along with enlarged lymph nodes and pleural effusion. In patients with concurrent pneumonia, underlying conditions such as cardiac diseases, diabetes mellitus and malignancy were significantly more frequent than in patients with KPP alone. The mortality rate in patients with KPP combined with MRSA or PA was significantly higher than in those with KPP alone. In concurrent KPP, CT findings of centrilobular nodules, bronchial wall thickening, cavity, bronchiectasis, nodules and pleural effusion were significantly more frequent with concurrent pneumonia than in those with KPP alone.

Figure 1

Acute Klebsiella pneumoniae pneumonia in an 82-year-old female alcoholic with a smoking habit at 2 days after onset of fever and cough with sputum. Transverse thin-section CT of right upper lobe shows consolidation (arrowhead), ground-glass attenuation and intralobular reticular opacity (arrow). Interlobular septal thickening (white arrowhead) is also present.

Figure 2

Acute concurrent Klebsiella pneumoniae pneumonia with methicillin-resistant Staphylococcus aureus in a 61-year-old male alcoholic with cardiac disease at 4 days after onset of fever, cough and chest pain. Transverse thin-section CT of left upper lobe shows consolidation with cavity (arrow) and bronchiectasis (white arrows).

Figure 3

Acute concurrent Klebsiella pneumoniae pneumonia with MRSA in a 75-year-old male alcoholic with cardiac disease and diabetes mellitus at 4 days after onset of fever, cough with sputum and dyspnoea. Transverse thin-section CT 1 cm below the tracheal carina shows consolidation with cavity (arrows), centrilobular nodules (arrowheads) and bronchial wall thickening (white arrow) with peripheral distribution. Pleural effusion is also present.

Figure 4

Acute concurrent Klebsiella pneumoniae pneumonia with Pseudomonas aeruginosa in a 35-year-old female alcoholic with a smoking habit at 3 days after onset of fever, cough with sputum and general weakness. (a) Transverse thin-section CT of the right upper lobe shows consolidation with cavity (arrow) and ground-glass opacity (white arrowheads). (b) Pre-tracheal lymph node enlargement is present (white arrow).