2008-2009 Influenza Season Week 20 ending May 23, 2009

All data are preliminary and may change as more reports are received.(Due to the response to the novel influenza A (H1N1) investigation, surveillance regions were changed from Census Divisions to Department of Health and Human Services (HHS) Regions.)Synopsis: During week 20 (May 17 - 23, 2009), influenza activity decreased in the United States, however there are still higher levels of influenza-like illness than is normal for this time of year.External_F0920.pdf2009647