Emergencies preparedness, response

Pandemic (H1N1) 2009 - update 64

Weekly update (Virological surveillance data)

The Global Influenza Surveillance Network (GISN) continues monitoring the global circulation of influenza viruses, including seasonal viruses.

Since the beginning of the pandemic in 19 April 2009 to August 15th 2009, a total of 80 countries reported to FluNet, the WHO influenza virological database. The total number of specimens reported positive for influenza viruses by National Influenza Centres (NICs) was 85923. Of these, 50,888 (59.2%) were pandemic (H1N1), 5259 (6.1%) were seasonal A (H1), 11,496 (13.4%) were A (H3), 14,816 (17.2%) were A (not subtyped) and 3464 (4.1%) were influenza B.

Twenty six countries reported to the FluNet on week 34. The total number of specimens reported positive for influenza viruses by the NICs in these countries was 6329. Of these, 3867 (61.1%) were pandemic (H1N1), 215 (3.4%) were seasonal A (H1), 1416 (22.4%) were A (H3), 730 (11.5%) were A (not subtyped) and 101 (1.6%) were influenza B. On average, the pandemic (H1N1) accounted for 61% of all influenza detections. Pandemic (H1N1) influenza virus continues to be the predominant circulating virus of influenza, both in the northern and southern hemisphere.

Virology data update

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