Swine Flu 2009 Situation Update 22 Jan 2010

Pandemic (H1N1) 2009 - update 84

Weekly update

22 January 2010 -- As of 17 January 2010, worldwide more than 209 countries and overseas territories or communities have reported laboratory confirmed cases of pandemic influenza H1N1 2009, including at least 14142 deaths.

WHO is actively monitoring the progress of the pandemic through frequent consultations with the WHO Regional Offices and member states and through monitoring of multiple sources of information.

Situation update:

The overall situation in largely unchanged since last week. The most intense transmission of pandemic influenza virus continues to occur in North Africa, South Asia, and in limited areas of Eastern Europe. Overall pandemic influenza activity in the temperate northern hemisphere peaked between late October and late November 2009 and has continued to decline since.

In North Africa, limited data suggest that transmission of pandemic influenza virus remains geographically widespread and active throughout the region, but has likely recently peaked in most places. During early January 2010 only the Libyan Arab Jamahiriya reported an increasing trend in respiratory diseases activity. Egypt is now reporting a declining trend after increases in respiratory diseases activity throughout December 2009, suggesting a recent peak in activity during early January 2010. In West Asia, limited data suggests pandemic influenza virus transmission remains geographically widespread however overall activity has been declining in most places during December and January.

In South Asia, active transmission of pandemic influenza virus persists in the northern and western parts of the subcontinent, however overall activity has recently peaked. In India, influenza activity has been largely confined to the northern and western states; activity in the northern states peaked during mid December 2009 and in the western states during early January 2010. In Nepal, active transmission of virus persists, and the trend in respiratory diseases activity remains unchanged since the previous week after reporting continuous increases in activity since late October 2009.

In Europe, pandemic influenza virus transmission remains geographically widespread across parts of western, central, and southeastern Europe, however overall influenza activity continued to decline or remain low in most countries The areas of most intense transmission currently include Poland, Austria, Estonia, Romania, Hungary, and Moldova; however, in all but Romania, ILI activity has declined significantly since peaking in November. The overall rate of specimens testing positive for influenza fell to 20% in Europe after reaching a peak of 45% during early November 2009. Pandemic H1N1 2009 virus continues to be predominant circulating influenza virus in the European region with only sporadic detections of seasonal influenza viruses.

In East Asia, pandemic influenza activity remains widespread but continues to decline in most places. Mongolia reported a very high intensity of respiratory diseases during early January 2010; rates of ILI have been elevated above expected seasonal levels since late October 2009 but are well below a significant peak of activity observed during November 2009. In Japan, overall influenza activity continued to decline since peaking at the end of November 2009, however regional increases in activity were observed during late December on the southern island of Okinawa. In China, Hong Kong SAR, and Chinese Taipei pandemic influenza activity remains widespread but continues to decline or remain stable. Pandemic H1N1 continues to be the predominant circulating virus in the region but seasonal H3N2 viruses continue to circulate in very small numbers in northern China.

In the Americas, both in the tropical and northern temperate zones, overall pandemic influenza activity continued to decline or remain low in most places.

In temperate regions of the southern hemisphere, sporadic cases of pandemic influenza continued to be reported without evidence of sustained community transmission.

The Global Influenza Surveillance Network (GISN) continues monitoring the global circulation of influenza viruses, including pandemic, seasonal and other influenza viruses infecting, or with the potential to infect, humans including seasonal influenza. For more information on virological surveillance and antiviral resistance please see the weekly virology update (Virological surveillance data, below).

Weekly update (Virological surveillance data)

*Countries in temperate regions are defined as those north of the Tropic of Cancer or south of the Tropic of Capricorn, while countries in tropical regions are defined as those between these two latitudes.

**Abbreviations: influenza-like-illness (ILI), acute respiratory infection (ARI), and severe acute respiratory infection (SARI)

Qualitative indicators (Week 29 to Week 1: 13 July 2009 - 10 January 2010)

The qualitative indicators monitor: the global geographic spread of influenza, trends in acute respiratory diseases, the intensity of respiratory disease activity, and the impact of the pandemic on health-care services.

Human infection with pandemic (H1N1) 2009 virus: updated interim WHO guidance on global surveillance
A description of WHO pandemic monitoring and surveillance objectives and methods can be found in the updated interim WHO guidance for the surveillance of human infection with pandemic (H1N1) virus.

The maps below display information on the qualitative indicators reported. Information is available for approximately 60 countries each week. Implementation of this monitoring system is ongoing and completeness of reporting is expected to increase over time.

List of definitions of qualitative indicators

Geographic spread of influenza activity

Map timeline

Trend of respiratory diseases activity compared to the previous week

Map timeline

Intensity of acute respiratory diseases in the population

Map timeline

Impact on health care services

Map timeline

Laboratory-confirmed cases of pandemic (H1N1) 2009 as officially reported to WHO by States Parties to the IHR (2005) as of 10 January 2010

Map of affected countries and deaths

The countries and overseas territories/communities that have newly reported their first pandemic (H1N1) 2009 confirmed cases since the last web update (No. 83): Mali.

The countries and overseas territories/communities that have newly reported their first deaths among pandemic (H1N1) 2009 confirmed cases since the last web update (No. 83): none.

Region	Deaths*
WHO Regional Office for Africa (AFRO)	131
WHO Regional Office for the Americas (AMRO)	At least 7094
WHO Regional Office for the Eastern Mediterranean (EMRO)	941
WHO Regional Office for Europe (EURO)	At least 3099
WHO Regional Office for South-East Asia (SEARO)	1366
WHO Regional Office for the Western Pacific (WPRO)	1511
Total*	At least 14142

* The reported number of fatal cases is an under representation of the actual numbers as many deaths are never tested or recognized as influenza related.