Influenza

Influenza update

15 June 2015, - Update number 239, based on data up to 30 May 2015

Summary

Globally, influenza activity has decreased from its peak of influenza activity in early 2015 to low levels in the Northern Hemisphere.

  • In North America, influenza activity was at inter-seasonal levels. Influenza B remained predominant in recent weeks, but at low levels.
  • In Europe, countries reported low influenza activity levels with influenza B continuing to dominate in recent weeks.
  • In northern Africa and western Asia, influenza activity remained low in most countries with influenza A activity predominant.
  • In the temperate countries of Asia, influenza activity continued to remain at low levels in most countries.
  • In tropical countries of the Americas and tropical Asia, influenza activity continued to decrease and remained low in most countries. In China, Hong Kong (SAR) and Singapore had slight increases in influenza activity while Sri Lanka and Viet Nam both reported a higher level of activity compared to recent weeks.
  • In the southern hemisphere, influenza activity was slightly higher in most countries but remained at low levels. However, South Africa reported a greater increase in influenza activity in recent weeks, with co-circulation of A(H1N1)pdm09 and A(H3N2) viruses.
  • National Influenza Centres (NICs) and other national influenza laboratories from 75 countries, areas or territories reported data to FluNet for the time period from 17 May 2015 to 30 May 2015 (data as of 11 June 2015, 13:25 UTC). The WHO GISRS laboratories tested more than 42 971 specimens during that time period. 2426 were positive for influenza viruses, of which 1174 (48.4%) were typed as influenza A and 1252 (51.6%) as influenza B. Of the sub-typed influenza A viruses, 212 (22.9%) were influenza A(H1N1)pdm09 and 712 (77.1%) were influenza A(H3N2). Of the characterized B viruses, 263 (93.3%) belonged to the B-Yamagata lineage and 19 (6.7%) 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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