Influenza

Influenza update - 303

27 November 2017, - Update number 303, based on data up to 12 November 2017

Summary

Influenza activity increased slightly in the temperate zone of the northern hemisphere while in the temperate zone of the southern hemisphere activity appeared to have decreased at inter-seasonal levels. In Central America and the Caribbean, influenza activity remained low. Worldwide, influenza A(H3N2) and B viruses accounted for the majority of influenza detections.

  • In North America, overall influenza activity continued to increase in the region, with detections of predominantly influenza A(H3N2) viruses.
  • In Europe, influenza activity remained low, with detections of predominantly influenza A(H3N2) and B viruses.
  • In Western Asia, influenza activity was low in general. In Qatar, influenza activity continued to increase, with all seasonal subtypes co-circulating.
  • In Central Asia, respiratory illness indicators appeared to increase in Kazakhstan, Tajikistan and Uzbekistan.
  • In East Asia, influenza activity remained low in general. In Northern China, influenza A(H3N2) detections increased slightly in recent weeks.
  • In South East Asia, influenza activity continued to decrease, with influenza A(H3N2) and B viruses most frequently detected.
  • In Southern Asia, influenza activity remained low in general. In India, influenza A(H1N1)pdm09 and A(H3N2) detections continued to be reported.
  • In Northern Africa, sporadic influenza A virus detections were reported in Morocco and Tunisia.
  • In Eastern, Middle and Western Africa, influenza detections continued to be reported, with all seasonal influenza subtypes present in the regions.
  • In the Caribbean and Central American countries, respiratory illness indicators and influenza activity remained low in general but respiratory syncytial virus (RSV) activity remained high in several countries.
  • In the tropical countries of South America, influenza and RSV activity remained at low levels overall.
  • In the temperate zone of the Southern Hemisphere, influenza activity appeared to have decreased overall.
  • National Influenza Centres (NICs) and other national influenza laboratories from 84 countries, areas or territories reported data to FluNet for the time period from 30 October 2017 to 12 November 2017 (data as of 2017-11-24 03:35:24 UTC).The WHO GISRS laboratories tested more than 103642 specimens during that time period. 5515 were positive for influenza viruses, of which 3690 (66.9%) were typed as influenza A and 1825 (33.1%) as influenza B. Of the sub-typed influenza A viruses, 509 (21.4%) were influenza A(H1N1)pdm09 and 1873 (78.6%) were influenza A(H3N2). Of the characterized B viruses, 781 (77.9%) belonged to the B-Yamagata lineage and 221 (22.1%) to the B-Victoria lineage.

Detailed influenza update

Seasonal update




Source of data