Content on this page was developed during the 2009-2010 H1N1 pandemic and has not been updated.
- The H1N1 virus that caused that pandemic is now a regular human flu virus and continues to circulate seasonally worldwide.
- The English language content on this website is being archived for historic and reference purposes only.
- For current, updated information on seasonal flu, including information about H1N1, see the CDC Seasonal Flu website.
Map: International Co-circulation of 2009 H1N1 and Seasonal Influenza
(As of November 21, 2009; posted November 30, 2009, 5:30 PM ET)