H1N1 influenza

H1N1 influenza is a strain of influenza that notably resulted in a pandemic in 2009.

It is caused by a type of influenza A virus of swine origin.

There can be a wide spectrum of clinical syndromes ranging from being asymptomatic to fulminant viral pneumonia, respiratory failure and death.

It can have a variable presentation and a number of features have been described 2:

  • initial chest radiographs usually show central or peripheral pulmonary ground-glass opacities (GGO) and consolidations that have a patchy or nodular appearance
  • multizonal and bilateral peripheral opacities are associated with adverse prognosis
  • it should be stressed that a normal radiograph cannot exclude a poor outcome

Described imaging spectrum is broad, with each individual feature being non-specific on its own 2-3:

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Article information

rID: 32660
System: Chest
Synonyms or Alternate Spellings:
  • H1N1 influenza infection
  • H1N1 pneumonia
  • H1N1 pneumonitis
  • H1N1 pulmonary infection
  • Novel influenza A infection
  • Novel influenza A pulmonary infection
  • Swine-origin influenza A
  • Swine flu infection
  • Swine-Origin Influenza A infection

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