H7N9 Avian Influenza virus

H7N9 Avian Influenza virus

01 May 2013

Important information for GPs

As of 10 April, 2013, 24 cases of H7N9 avian influenza have been reported in China, including 7 deaths. No cases have been reported from outside China. Although the environmental source has not yet been definitively determined, some of the confirmed cases have been associated with contact with chickens or poultry or an animal wet market environment. Influenza (A)H7 viruses are a group of influenza viruses that normally circulate among birds. H7N9 is a reassortant derived from three different avian influenza viruses.

This strain is distinct from the H1N1/09 swine influenza (that caused the 2009 pandemic in humans) and H5N1 avian influenza.

Key points for GPs

  • Most of the cases of H7N9 avian influenza to date have presented with a severe acute febrile lowerrespiratory tract illness (with severe pneumonia and/or Acute Respiratory Distress Syndrome (ARDS) although mild cases have been reported.
  • There is currently no evidence of person-to-person transmission of H7N9 influenza
  • In general practice, common causes of pneumonia and influenza should be assessed through routine investigation and testing for community acquired pneumonia and influenza, as these remain much more likely than H7N9 avian influenza even in persons returned from China.
  • The information below is intended to guide GPs assessment of patients recently returned from China (excluding Hong Kong) who present with acute febrile lower respiratory tract infections
Clinical presentation of confirmed H7N9 avian influenza cases to date
Most cases have presented with a severe acute febrile lower respiratory tract illness (with pneumonia and/or Acute Respiratory Distress Syndrome) although mild cases have been reported. There is currently no evidence of person-to-person transmission of H7N9 avian influenza.

For patients with acute febrile lower respiratory tract illness who have not been to China

To date, no cases have been detected outside China, so patients whose travel history does not include China can be reassured.