Global Alert and Response (GAR)

Influenza - update 114

Situation update:

The situation in New Zealand and India remains largely unchanged since the last update. Influenza H1N1 (2009) virus transmission remains locally intense in parts of India and New Zealand.

In New Zealand, during the first week of August 2010, the national consultation rate for ILI** increased sharply. Influenza H1N1 (2009) virus transmission appears to be locally intense in parts of the country that were less affected during last winter's pandemic wave; however, to date, the overall national rate of ILI consultations and the numbers of severe and fatal cases of H1N1 (2009) remain below levels observed during the 2009 winter pandemic wave. The majority of influenza viruses detected during the current winter epidemic have been H1N1 (2009).

In India, community transmission of H1N1 (2009) remained active and moderately intense in several states, most notably in the states of Maharashtra but also in several other western and southern states (Gujarat, Andhra Pradesh, Karnataka, and Tamil Nadu). Between mid-June 2010 and the second week of August 2010, the state of Maharashtra reported consecutive weekly increases in the number of new cases, including numbers of new fatal cases; the epidemic does not appear to have peaked in Maharashtra but the rate of increase in the numbers of new cases appears to have slowed. The epidemic appears to have stabilized or begun to decline in several other affected states. Seasonal influenza B viruses are also known to be currently circulating in India, although at lower levels than H1N1 (2009) viruses.

Except in South Africa and New Zealand, overall influenza activity and rates of respiratory diseases remained low in other countries of the temperate southern hemisphere (Australia, Chile, and Argentina). In South Africa, active circulation of seasonal influenza H3N2 and type B viruses was observed during June through mid-August 2010. In Argentina, there are unconfirmed media reports of localized influenza outbreaks in at least one part of the country.

*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)

MAP OF INFLUENZA ACTIVITY AND VIRUS SUBTYPES (WEEK 31: 1 AUGUST - 7 AUGUST 2010)

  • Map of influenza activity and virus subtypes
    jpg, 840kb

    Description: Displayed data reflect the most recent data reported to Flunet (www.who.int/FluNet), WHO regional offices or on Ministry of health websites in the last 2 weeks. The percent of specimens tested positive for influenza includes all specimens tested positive for seasonal or pandemic influenza. The pie charts show the distribution of virus subtypes among all specimens that were tested positive for influenza. The available country data were joined in larger geographical areas with similar influenza transmission patterns to be able to give an overview (http://www.who.int/csr/disease/swineflu/transmission_zones/en)

Qualitative indicators (Week 29, 2009 to Week 31, 2010: 13 July 2009 - 7 August 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.

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
Map of laboratory-confirmed cases of H1N1 (2009) as officially reported to WHO by States Parties to the IHR (2005) as of 8 August 2010
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