Influenza

Influenza update - 296

21 August 2017, - Update number 296, based on data up to 06 August 2017

Summary

In the temperate zone of the southern hemisphere and in some countries of South and South East Asia, high levels of influenza activity continued to be reported. In Central America and the Caribbean influenza activity continued to be reported in a few countries. Influenza activity remained at low levels in the temperate zone of the northern hemisphere. Worldwide, influenza A(H3N2) viruses are predominating.

  • In temperate South America, influenza activity, severe acute respiratory infection (SARI) and influenza like illness (ILI) indicators decreased in the countries reporting data. Influenza A(H3N2) viruses predominated in the region with some B virus activity reported as well.
  • In Southern Africa, influenza activity was reported from several countries but appeared to have peaked already in South Africa, with influenza A(H3N2) viruses predominantly detected.
  • In Oceania, seasonal influenza activity continued to increase, with influenza A(H3N2) and B viruses present in the region.
  • In tropical South America, influenza activity remained low.
  • In the Caribbean and Central American countries, respiratory illness indicators and influenza activity remained low in general with a few exceptions but Respiratory Syncytial Virus (RSV) activity was increasing.
  • In Southern Asia, increased influenza A(H1N1)pdm09 virus detections were reported in India, Myanmar and Nepal in recent weeks.
  • In South East Asia, increased influenza activity was reported in recent weeks, with all seasonal influenza subtypes present in the region.
  • In East and Western Asia, influenza activity remained low in general.
  • In Western Africa, influenza activity continued to be reported, with influenza A(H1N1)pdm09 and A(H3N2) viruses co-circulating in in Côte d’Ivoire, Ghana, and Togo, and influenza B Victoria lineage predominant in Senegal. Few influenza detections were reported in Eastern and Middle Africa.
  • In Northern Africa, no influenza virus detections were reported.
  • In Central Asia, there were no updated reports on virus detections or respiratory illness indicators.
  • In Europe and North America, little to no influenza activity was reported.
  • National Influenza Centres (NICs) and other national influenza laboratories from 75 countries, areas or territories reported data to FluNet for the time period from 24 July 2017 to 06 August 2017 (data as of 2017-08-18 03:36:54 UTC).The WHO GISRS laboratories tested more than 50456 specimens during that time period. 8401 were positive for influenza viruses, of which 7644 (91%) were typed as influenza A and 757 (9%) as influenza B. Of the sub-typed influenza A viruses, 779 (11.6%) were influenza A(H1N1)pdm09 and 5930 (88.4%) were influenza A(H3N2). Of the characterized B viruses, 168 (63.4%) belonged to the B-Yamagata lineage and 97 (36.6%) to the B-Victoria lineage.

Detailed influenza update

Seasonal update




Source of data