Influenza Update N° 263 16 May 2016, based on data up to 1 May, 2016

Summary Influenza activity in the continued to decrease. A predominance of influenza B virus activity continued to be reported in most of the northern hemisphere and in some tropical areas. In a few countries in the , slight increases in influenza-like illness (ILI) activity were reported.

. In , influenza activity continued to decrease with influenza B detections predominating. . and temperate reported decreased influenza activity with a continued predominance of influenza B virus activity. . In North , influenza activity continued to decrease in general, except in Egypt where in recent weeks influenza B activity continued. . Influenza A virus was reported predominant in Eastern and Western Africa. . In and the countries, influenza and other respiratory virus activity remained generally low, although levels of A(H1N1)pdm09 virus activity remained elevated in El Salvador and Guatemala. Active circulation of influenza A(H1N1)pdm09 activity was also reported in several countries in the Caribbean. . In parts of tropical , low but increasing influenza A(H1N1)pdm09 activity was reported in Bolivia and Ecuador. In Peru, influenza detections decreased. In Brazil, influenza activity continued at elevated levels with a predominance of influenza A(H1N1)pdm09 virus. Respiratory syncytial virus (RSV) activity remained elevated in Colombia. . In tropical countries of , influenza activity decreased with influenza B virus predominant. . In temperate South America, respiratory virus activity remained low. ILI activity increased slightly in a few countries but remained below seasonal thresholds. . In the temperate countries of and , influenza virus activity remained low. Some islands in the Pacific reported increased ILI activity. . National Influenza Centres (NICs) and other national influenza laboratories from 90 countries, areas or territories reported data to FluNet for the time period from 18 April 2016 to 01 May 2016 (data as of 2016-05-13 03:33:09 UTC).The WHO GISRS laboratories tested more than 85968 specimens during that time period. 12819 were positive for influenza viruses, of which 4580 (35.7%) were typed as influenza A and 8239 (64.3%) as influenza B. Of the sub-typed influenza A viruses, 1728 (81.5%) were influenza A(H1N1)pdm09 and 391 (18.5%) were influenza A(H3N2). Of the characterized B viruses, 353 (20.6%) belonged to the B-Yamagata lineage and 1358 (79.4%) to the B- lineage.

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Countries in the temperate zone of the northern hemisphere

North America For more information see: http://www.paho.org/hq/index.php?option=com_content&view=article&id=3352%3A2010-influenza- situation-report&catid=2407%3Ainfluenza-other-respiratory-viruses&Itemid=2469&lang=en Number of specimens positive for influenza by subtype in North America

Data source: FluNet (www.who.int/flunet). Global Influenza Surveillance and Response System (GISRS) Data generated on 16/05/16

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Europe For more information see: https://flunewseurope.org/

Number of specimens positive for influenza by subtype in the European of WHO

Data source: FluNet (www.who.int/flunet). Global Influenza Surveillance and Response System (GISRS) Data generated on 12/05/16

Western Asia In , influenza activity continued to decrease to low levels with mainly influenza B virus detected.

Central Asia For more information see: https://flunewseurope.org/

Northern Temperate Asia In Northern Temperate Asia, influenza activity continued to decrease during this reporting period with influenza B virus predominant. ILI activity decreased in Mongolia, however deaths among individuals hospitalized for pneumonia increased slightly. In , Northern China and the Republic of , ILI activity decreased to near inter-seasonal levels, with influenza B virus predominating.

Number of specimens positive for influenza by subtype in Northern Temperate Asia

Data source: FluNet (www.who.int/flunet). Global Influenza Surveillance and Response System (GISRS) Data generated on 13/05/16

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Countries in the tropical zone

Tropical countries of Central America, the Caribbean and South America For more information see: http://www.paho.org/hq/index.php?option=com_content&view=article&id=3352%3A2010-influenza- situation-report&catid=2407%3Ainfluenza-other-respiratory-viruses&Itemid=2469&lang=en

African region Influenza virus detections in Northern Africa were mainly influenza B virus, except in Tunisia where A(H1N1)pdm09 was predominant. Influenza activity decreased in general in the region, except in Egypt where influenza B virus detections increased in recent weeks.

In Eastern and Western Africa, influenza activity was low with predominantly influenza A virus detected. Influenza virus A(H1N1)pdm09 co-circulated with A(H3N2) in Ghana and A(H1N1)pdm09 was predominant in Côte d’Ivoire and Mali. Influenza B virus activity peaked and continued to decrease further during this reporting period in Kenya.

Tropical Asia Overall, influenza activity in southern Asia and South- was low with influenza B virus predominant. Influenza detections decreased in Southern China and Hong Kong SAR with influenza B virus predominant. ILI activity decreased but remained above inter-seasonal levels.

Number of specimens positive for influenza by subtype in South-East Asia

Data source: FluNet (www.who.int/flunet). Global Influenza Surveillance and Response System (GISRS) Data generated on 13/05/16

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Countries in the temperate zone of the southern hemisphere

Temperate South America For more information see: http://www.paho.org/hq/index.php?option=com_content&view=article&id=3352%3A2010-influenza- situation-report&catid=2407%3Ainfluenza-other-respiratory-viruses&Itemid=2469&lang=en

Southern Africa Inter-seasonal levels of influenza activity continued in South Africa.

Oceania, Melanesia and Overall influenza activity remained low. and reported minimal detections of influenza A(H1N1)pdm09 virus. Increased ILI activity was reported in some parts of the Pacific, including , American and Federal States of .

Number of specimens positive for influenza by subtype in the southern hemisphere

Data source: FluNet (www.who.int/flunet). Global Influenza Surveillance and Response System (GISRS) Data generated on 12/05/16

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Source of data

The Global Influenza Programme monitors influenza activity worldwide and publishes an update every two weeks. The updates are based on available epidemiological and virological data sources, including FluNet (reported by the WHO Global Influenza Surveillance and Response System) FluID (epidemiological data reported by national focal points) and influenza reports from WHO Regional Offices and Member States. Completeness can vary among updates due to availability and quality of data available at the time when the update is developed.

Link to web page

Influenza reports from WHO Regional Offices: AMRO: www.paho.org/influenzareports EURO: http://www.flunewseurope.org/ WPRO: http://www.wpro.who.int/emerging_diseases/Influenza

Epidemiological Influenza updates: http://www.who.int/influenza/surveillance_monitoring/updates/latest_update_GIP_surveillance Epidemiological Influenza updates archives 2015: http://www.who.int/influenza/surveillance_monitoring/updates/GIP_surveillance_2015_archives Virological surveillance updates : http://www.who.int/influenza/gisrs_laboratory/updates/summaryreport Virological surveillance updates archives : http://www.who.int/influenza/gisrs_laboratory/updates/

Contact [email protected]

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