Influenza

Influenza update - 300

16 October 2017, - Update number 300, based on data up to 01 October 2017

Summary

Influenza activity remained at low levels in the temperate zone of the northern hemisphere. Declining levels of influenza activity were reported in the temperate zone of the southern hemisphere and in some countries of South and South East Asia. In Central America and the Caribbean, low influenza activity was reported in a few countries. Worldwide, influenza A(H3N2) and B viruses accounted for the majority of influenza detections.

  • In temperate South America, influenza and respiratory syncytial virus (RSV) activity continued a downward trend throughout most of the sub-region.
  • In Southern Africa, influenza activity continued to decrease in South Africa, with influenza B viruses most frequently detected.
  • In Oceania, seasonal influenza activity started to decline, with influenza A(H3N2) predominant, followed by B viruses.
  • In tropical South America, influenza and RSV activity remained at low levels overall.
  • In the Caribbean and Central American countries, respiratory illness indicators and influenza activity remained low in general but RSV activity remained high in several countries.
  • In Southern Asia, decreasing levels of influenza activity were reported in India and Bhutan, with A(H1N1)pdm09 most frequently detected.
  • In South East Asia, influenza activity appeared to decrease in general, with some exceptions. Influenza activity increased in Cambodia and remained high in Lao PDR, with influenza A(H3N2) viruses predominantly detected.
  • In Western Asia, influenza activity continued to increase in Oman, with influenza A(H1N1)pdm09 and A(H3N2) viruses co-circulating. Increased influenza A detections were reported in Bahrain in recent weeks.
  • In East Asia, influenza activity remained low in general.
  • In Western Africa, influenza detections continued to be reported, with all seasonal influenza subtypes present in the region. In Middle Africa, elevated ILI activity was reported in Cameroon. In Eastern Africa, influenza detections and ILI activity increased sharply in Réunion Island (French Overseas Department), with influenza B viruses predominant.
  • In Northern Africa, little to no influenza virus detections was reported.
  • In Central Asia, there were no updated reports on virus detections or respiratory illness indicators.
  • In Europe, little to no influenza activity was reported.
  • In North America, overall influenza virus activity remained low with detections of predominantly influenza A(H3N2) and B viruses in the past few weeks.
  • National Influenza Centres (NICs) and other national influenza laboratories from 85 countries, areas or territories reported data to FluNet for the time period from 18 September 2017 to 01 October 2017 (data as of 2017-10-13 03:40:32 UTC).The WHO GISRS laboratories tested more than 56528 specimens during that time period. 3496 were positive for influenza viruses, of which 2566 (73.4%) were typed as influenza A and 930 (26.6%) as influenza B. Of the sub-typed influenza A viruses, 260 (15.1%) were influenza A(H1N1)pdm09 and 1460 (84.9%) were influenza A(H3N2). Of the characterized B viruses, 192 (81%) belonged to the B-Yamagata lineage and 45 (19%) to the B-Victoria lineage.
  • The vaccine recommendation for the 2018 southern hemisphere influenza season was made and can be consulted at this link below:

Detailed influenza update

Seasonal update




Source of data