WHO

Summary

In the Northern Hemisphere high levels of influenza activity continued with influenza A(H1N1)pdm09 predominating and an increase in the proportion of influenza B viruses detected. In the Southern Hemisphere and in tropical countries influenza activity was generally low.

• In Europe ongoing high levels of influenza activity continued to be reported, although in some countries activity seemed to have peaked already. Influenza A(H1N1)pdm09 accounted for most virus detections with an increase in the proportion of influenza B detections. In Russian Federation and Ukraine, elevated SARI activity continued but at lower levels compared to previous weeks.
• In North America, influenza activity increased further with influenza A(H1N1)pdm09 predominating in Canada and United States of America and A(H3N2) in Mexico.
• In Northern/Temperate Asia, influenza activity remained high but seemed to have peaked already in some countries.
• In Western Asia, influenza activity continued to decrease. Oman reported ongoing low levels of both influenza A(H1N1)pdm09 and influenza B viruses.
• In Africa influenza A(H1N1)pdm09 activity was reported in northern Africa.
• In tropical countries of the Americas, Central America and the Caribbean, influenza and other respiratory virus activity were overall at low levels, except Jamaica, and Puerto Rico with high but decreasing influenza activity.
• In South East Asia, ongoing low influenza activity was reported during this period.
• In the temperate countries of the Southern Hemisphere influenza activity remained low at inter-seasonal level.
• National Influenza Centres (NICs) and other national influenza laboratories from 98 countries, areas or territories reported data to FluNet for the time period from 08 February 2016 to 21 February 2016* (data as of 2016-03-04 07:20:12 UTC).The WHO GISRS laboratories tested more than 158158 specimens during that time period. 42727 were positive for influenza viruses, of which 33745 (79%) were typed as influenza A and 8982 (21%) as influenza B. Of the sub-typed influenza A viruses, 19269 (87.7%) were influenza A(H1N1)pdm09 and 2709 (12.3%) were influenza A(H3N2). Of the characterized B viruses, 589 (24.4%) belonged to the B-Yamagata lineage and 1821 (75.6%) to the B-Victoria lineage.