Influenza A pneumonia

Case contributed by Joachim Feger
Diagnosis certain


Admitted early March 2020, somewhere in the middle of nowhere in Germany with fever, dry cough and pleuritic pain, hypoxia, and hypocapnia.

Patient Data

Age: 60 years
Gender: Female

Mildly increased cardiothoracic ratio (CTR): 52%.

Patchy, bilateral infiltrates, and airspace opacification predominantly in the mid and lower lung zones.

No visible pleural effusions.


Thoracic CT


Quality: suboptimal inspiration


  • normal contrast in the pulmonary arteries, coronary artery calcification
  • no significant mediastinal lymphadenopathy
  • bilateral irregular consolidations along the bronchovascular bundles in the lower lobes and middle lobe, with air bronchograms
  • extensive patchy bilateral ground-glass opacities (GGO) with small consolidations again along and around the bronchovasular bundles and bronchial wall thickening


Bilateral ground-glass opacities (GGO) and consolidations suggestive of atypical pneumonia.

Annotated image

Key findings:

  • irregular areas of consolidation along the bronchovascular bundles pronounced in middle and lower lobes (arrows)
  • diffuse ground-glass opacities again along and around the broncho-vascular bundles (red arrowheads), areas with interlobar thickening (blue arrowheads), and bronchial wall thickening (orange arrows)
  • combinations of ground-glass opacities and consolidation (blue arrows)

Case Discussion

This case illustrates and shows the most common findings of influenza A pneumonia a combination of multifocal ground-glass opacities (GGO) and irregular consolidations, mainly along and around the bronchovascular bundles.

Real-time polymerase chain reaction (PCR) after respiratory swab was positive for influenza A virus RNA.

The patient was put under isolation and received supportive and antiviral therapy (oseltamivir) and an antibiotic regimen covering gram-positive cocci for 7 days. After a hospital course of 8 days, the patient recovered and was released home in a vastly improved condition.

Outpatient follow-up CT, three weeks later, was normal and showed complete resolution of the ground glass opacities and consolidations.

This is also an important differential diagnosis for COVID-19 pneumonia.

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