Influenza activity in the world

29 January 2010

This summary provides an updated summary of both pandemic influenza A (H1N1) 2009 virus and seasonal influenza activity for weeks 52-53 of 2009 (as of 29 January 2010). Detailed reports of the pandemic influenza A (H1N1) virus activity are available at: the WHO page for Pandemic (H1N1) 2009 . This summary does not include reports of avian influenza in humans, which are available at: the WHO avian influenza page .

Pandemic (H1N1) 2009

During the weeks 52-53, pandemic influenza A (H1N1) 2009 activity in the northern hemisphere continued to decrease. In tropical regions of the Americas and Asia, influenza activity was variable while activity in the southern hemisphere was sporadic.

In the northern hemisphere, widespread outbreaks of pandemic influenza A (H1N1) 2009 were reported in a few countries in central and southeastern Europe and in parts of Asia. In the United States of America and Canada activity decreased. Some countries in central America reported pandemic virus circulation and variable pandemic activity was reported in a few countries in the southern hemisphere.

Widespread outbreaks were reported in Costa Rica, Croatia, Ecuador, Georgia, Greece, Israel, Japan, Morocco, Panama, Republic of Moldova, Slovenia, Sri Lanka, Switzerland, Tunisia and Venezuela (Bolivarian Republic of).

Regional outbreaks were reported in Argentina, Austria, Bahamas, Brazil, China, Columbia, Estonia, France, Germany, India, Latvia, Madagascar, Mongolia, Netherlands, Norway, Poland, Romania, Serbia, Turkey, United States of America and Ukraine.

Local levels of pandemic influenza A (H1N1) activity were reported in Albania, Czech Republic, Iran (Islamic Republic of), Italy, Paraguay, Russian Federation, Slovakia, Spain, Sweden and United Kingdom.

Sporadic pandemic influenza A (H1N1) 2009 activity was reported in Belarus, Belgium, Bulgaria, Canada, Cape Verde, Chile, China Hong Kong Special Administrative Region, Cuba, Cyprus, Denmark, Finland, Hungary, Lithuania, Luxembourg, Mexico, New Zealand, Portugal and Thailand.

Seasonal influenza

The level of seasonal influenza activity was generally low with the exception of China where increased influenza B activity was reported. Sporadic seasonal influenza activity was observed in Afghanistan (H1), Cambodia (B), Canada (H3,B), China Hong Kong Special Administrative Region (H3,B), Iran (Islamic Republic of) (B), Russian Federation (H1,H3,B), Tunisia (B), Turkey (H3,B) and United States of America (B).

Australia, Azerbaijan, Cameroon, Dominica, Kenya and Uzbekistan reported no influenza activity.