Influenza

Influenza update

27 July 2015, - Update number 242, based on data up to 12 July 2015

Summary

Globally, the Southern hemisphere had increased influenza activity whereas influenza activity was at low levels in the Northern hemisphere.

  • In North America, Europe and temperate countries of Asia, influenza activity continued at low, inter-seasonal levels with influenza B predominating in sporadic detections.
  • In northern, middle, eastern and western Africa, only a few countries reported low levels of influenza activity with influenza type B predominating with low levels of co-circulation of influenza type A(H1N1)pdm09 and A(H3N2).
  • In tropical countries of the Americas/Central America and the Caribbean, overall influenza activity was reported to be at low, inter-seasonal levels with only Cuba reporting a slight increase in detections of influenza type A(H1N1)pdm09.
  • In western and temperate countries of Asia, low levels of influenza activity were reported with influenza B predominating with co-circulation of influenza type A(H1N1)pdm09 in western Asia in recent weeks. Northern China reported a slight increase in detections of influenza type A(H3N2).
  • In tropical Asia, countries in Southern Asia reported elevated but decreasing influenza activity with influenza type A(H3N2) predominating. South East Asia reported low levels of activity with influenza type A(H3N2) predominating with co-circulation of influenza type A(H3N2) and B.
  • In temperate South America, influenza activity increased with influenza type A(H1N1)pdm09 and type A(H3N2) predominating in recent weeks. Overall, influenza activity is following seasonal trends although at lower levels than in previous years. There was a sharp increase in influenza activity in Paraguay.
  • Influenza activity decreased in South Africa with influenza type A(H1N1)pdm09 and A(H3N2) predominating in recent weeks.
  • In Australia and New Zealand, influenza activity continued to increase with both influenza type A(H3N2) and type B in circulation.
  • National Influenza Centres (NICs) and other national influenza laboratories from 68 countries, areas or territories reported data to FluNet for the time period from 29 June 2015 to 12 July 2015 (data as of 2015-07-27 12:46:00 UTC).The WHO GISRS laboratories tested more than 21868 specimens during that time period. 2206 were positive for influenza viruses, of which 1680 (76.2%) were typed as influenza A and 525 (23.8%) as influenza B. Of the sub-typed influenza A viruses, 175 (12.9%) were influenza A(H1N1)pdm09 and 1178 (87.1%) were influenza A(H3N2). Of the characterized B viruses, 89 (94.7%) belonged to the B-Yamagata lineage and 5 (5.3%) to the B-Victoria lineage.

Detailed influenza update

Influenza surveillance outputs

Seasonal update


For regional updates on influenza see the following links


For updates on the influenza at the human-animal interface see the following WHO web pages:


Source of data

The Global Influenza Programme monitors influenza activity worldwide and publishes an update every two weeks.
The updates are based on available epidemiological and virological data sources, including FluNet (reported by the WHO Global Influenza Surveillance and Response System) and influenza reports from WHO Regional Offices and Member States. Completeness can vary among updates due to availability and quality of data available at the time when the update is developed.

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