H1N1 influenza

H1N1 influenza is a strain of influenza that notably resulted in a pandemic in 2009. It was referred to colloquially as 'swine flu' due to the origin of the virus, but it was also named H1N1/09 virus. A specific but different strain of H1N1 (called H1N1 influenza A) was the cause of the Spanish flu, one of the worst global pandemics in recorded human history ref. This article refers to the disease resulting from the H1N1/09 virus.

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

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

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

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:
  • H1N1/09 virus
  • 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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Cases and figures

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