Pandemic (H1N1) 2009 - update 77
4 December 2009 - As of 29 November 2009, worldwide more than 207 countries and overseas territories or communities have reported laboratory confirmed cases of pandemic influenza H1N1 2009, including at least 8768 deaths.
As many countries have stopped counting individual cases, particularly of milder illness, the case count is likely to be significantly lower than the actual number of cases that have occurred. 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 data.
In the temperate zone* of the northern hemisphere, the early arriving winter influenza season continues to intensify across central Europe and in parts of central, eastern, and southern Asia. Disease activity has peaked and is declining in North America and has either recently peaked or is currently peaking in much of western and northern Europe.
In both Canada and the United States, influenza virus circulation remains active and geographically widespread, however, disease activity appears to have peaked in past 3 to 4 weeks. In the United States, deaths due to pneumonia and influenza (P&I mortality) continued to increase past the epidemic threshold for the past 8 weeks and cumulative rates of hospitalizations for the current influenza season have exceeded rates seen in recent seasons among all age groups except those aged ≥ 65.
In Europe, widespread and intense transmission of pandemic influenza virus continued to be observed across most of the continent. In western and northern Europe the peak of disease activity has passed in Belgium, Iceland, Ireland, Netherlands, Norway and parts of the United Kingdom (Northern Ireland, Wales); activity may be peaking or plateauing in Spain, Portugal, Italy, Sweden and Denmark. Influenza activity continues to increase in much of Central Europe in the region between the Baltic and Balkan countries and from Germany to Romania. In Eastern Europe, recent peaks or plateaus in disease activity have also been observed in Ukraine, Belarus, Bulgaria and the Republic of Moldova. In the Russian Federation, influenza activity remains active and intense in some regions, with an overall increasing trend. A moderate impact on the healthcare system has been reported in parts of Northern and Eastern Europe. Over 99% of subtyped influenza A viruses in Europe were pandemic H1N1 2009.
In Western and Central Asia, influenza transmission remains active. Disease activity continues to increase in Kazakhstan, Kyrgyzstan, Uzbekistan, Iran and Iraq, while activity may have peaked in Israel, Jordan, and Afghanistan.
In East Asia, increasing ILI** or respiratory disease activity has been reported in Southern China and Japan. A recent decline in activity has been observed in Northern China. In South and Southeast Asia, influenza activity continues to increase in the north-western parts of India, Nepal, Sri Lanka, and Cambodia, while activity in the rest of region remain low.
In the tropical zone of Central and South America and the Caribbean, influenza transmission remains geographically widespread but overall disease activity has been declining except for focal areas of increasing activity in Jamaica, Venezuela, and Ecuador.
In Africa, pandemic H1N1 2009 virus continues to be isolated from all parts of the continent, and there is evidence of continued co-circulation of pandemic (H1N1) 2009 and seasonal H3N2 viruses.
In the temperate region of the southern hemisphere, little pandemic influenza activity has been reported.
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).
*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 47: 13 July - 22 November 2009)
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
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.
Geographic spread of influenza activity
Trend of respiratory diseases activity compared to the previous week
Intensity of acute respiratory diseases in the population
Impact on health care services
Laboratory-confirmed cases of pandemic (H1N1) 2009 as officially reported to WHO by States Parties to the IHR (2005) as of 29 November 2009
The countries and overseas territories/communities that have newly reported their first pandemic (H1N1) 2009 confirmed cases since the last web update (No.76): None.
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 76): Romania and Slovakia.