Influenza update - 280
09 January 2017, - Update number 280, based on data up to 25 December, 2016
Influenza activity in the temperate zone of the northern hemisphere continued to increase, with many countries especially in Europe and East Asia passing their seasonal threshold early in comparison with previous years. Worldwide, influenza A(H3N2) virus was predominant. The majority of influenza viruses characterized so far is similar antigenically to the reference viruses representing vaccine components for 2016-2017 influenza season. The majority of recently circulating viruses tested for antiviral sensitivity is susceptible to the neuraminidase inhibitor antiviral medications.
- In North America, influenza activity continued to increase with influenza A(H3N2) virus predominating. Influenza-like illness (ILI) levels just surpassed the seasonal thresholds in the United States. In the United States, respiratory syncytial virus (RSV) activity increased.
- In Europe, influenza activity was increasing, with influenza A (H3N2) virus being the most prominent subtype. Persons aged over 65 years were most frequently associated with severe disease.
- In East Asia, influenza activity continued to increase with influenza A(H3N2) viruses predominant.
- In Western Asia, influenza activity increased slightly.
- In Southern Asia influenza activity increased mainly due to influenza A(H3N2) . Increased activity was reported in recent weeks by the Islamic Republic of Iran and Sri Lanka.
- In South East Asia, influenza activity continued to decrease, with influenza A(H3N2) virus and influenza B predominating in the region.
- In Northern Africa, continued increased influenza detections were reported in Morocco and Tunisia with influenza A(H3N2) virus dominating.
- In West Africa, influenza continued to be detected in Ghana with B viruses dominating.
- In the Caribbean countries and Central America, influenza and other respiratory virus activity remained low in general.
- In tropical South America, influenza and other respiratory viruses activity remained low.
- In the temperate zone of the Southern Hemisphere, influenza activity is at inter-seasonal levels.
- National Influenza Centres (NICs) and other national influenza laboratories from 74 countries, areas or territories reported data to FluNet for the time period 12 December 2016 to 25 December 2016 (data as of 2017-01-06 04:12:46 UTC).The WHO GISRS laboratories tested more than 124657 specimens during that time period. Of these 25263 were positive for influenza viruses, of which 24223 (95.9%) were typed as influenza A and 1040 (4.1%) as influenza B. Of the sub-typed influenza A viruses, 159 (1.3%) were influenza A(H1N1)pdm09 and 11927 (98.7%) were influenza A(H3N2). Of the characterized B viruses, 67 (34.9%) belonged to the B-Yamagata lineage and 125 (65.1%) to the B-Victoria lineage.
Detailed influenza update
Source of data