Emergencies preparedness, response

Pandemic (H1N1) 2009 - update 76

Weekly update

As of 22 November 2009, worldwide more than 207 countries and overseas territories or communities have reported laboratory confirmed cases of pandemic influenza H1N1 2009, including over 7820 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.

Situation update:

In temperate regions* of the northern hemisphere, the early arriving winter influenza season continues to be intense across parts of North America and much of Europe. In North America, the Caribbean islands and a limited number of European countries there are signs that disease activity peaked.

In the United States and Canada, influenza transmission remains very active and geographically widespread. In the United States, disease activity appears to have peaked in all areas of the country. In Canada, influenza activity remains similar but number of hospitalisations and deaths is increasing. Most countries in the Caribbean have ILI and SARI levels coming down.

In Europe, widespread and increasing transmission of pandemic influenza virus was observed across much of the continent and most countries that were not yet experiencing elevated ILI activity in the last few weeks, have seen a rapid increase in ILI. Very high activity is seen in Sweden, Norway, Moldova and Italy. Over 99% of subtyped influenza A viruses in Europe were pandemic H1N1 2009. Impact on health care services is severe in Albania and Moldova. Some countries seem to have peaked already: Belgium, Bulgaria, Belarus, Ireland, Luxemburg, Norway, Serbia, Ukraine and Iceland.

In East Asia, influenza transmission remains active. Intense influenza activity continues to be observed in Mongolia but has peaked already. In Japan, influenza activity remains stably elevated, but may be decreasing slightly in populated urban areas.

ILI activity in India and Nepal and Sri Lanka has increased.

In the tropical zone of the Americas and Asia, influenza transmission remains variable but low in many countries. In the tropical areas of Central and South America, most countries continue to report declining influenza activity, with the exception of Ecuador and Venezuela.

In the temperate region of the southern hemisphere, little pandemic influenza activity has been reported.

*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 46: 13 July - 15 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.

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 22 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.75): Armenia.

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 75): The former Yugoslav Republic of Macedonia, Switzerland, Poland, Tunisia, Morocco and Madagascar.

*Given that countries are no longer required to test and report individual cases, the number of cases reported actually understates the real number of cases.

**The total number of cases are no longer reported from these regions