December 15, 2009
The number of influenza-like illnesses documented by the Centers for Disease Control and Prevention (CDC) fell in the week of December 6-12, marking the seventh straight week of declines. Even so, the health agency says the number of flu illnesses remains higher than normal for this time of year.
Almost all of the influenza viruses identified so far continue to be 2009 H1N1 influenza A viruses.
Eleven states -- Alabama, Alaska, California, Delaware, Kentucky, Maine, New Hampshire, New Jersey, Nevada, New York, and Virginia -- reported widespread influenza activity.
Visits to the doctor for flu illness decreased slightly over the previous week. This is the seventh consecutive week of national decreases in ILI after four consecutive weeks of sharp increases. While ILI has declined, visits to doctors for influenza-like illness remain slightly elevated nationally.
Influenza hospitalizations and hospitalization rates decreased in all age groups.
The proportion of deaths attributed to pneumonia and influenza (P&I) based on the 122 Cities Report decreased over the previous week, but remains elevated for this time of year. This proportion has been higher than expected for eleven consecutive weeks.
In addition, nine flu-related pediatric deaths were reported during the week. Eight of these deaths were associated with laboratory-confirmed 2009 H1N1 influenza, and one was associated with an influenza A virus that was not subtyped, the CDC said.
Since April 2009, the CDC has received reports of 276 laboratory-confirmed pediatric deaths. 232 were due to 2009 H1N1, 42 pediatric deaths that were laboratory confirmed as influenza, but the flu virus subtype was not determined, and two pediatric deaths that were associated with seasonal influenza viruses.
Laboratory-confirmed deaths are thought to represent an undercount of the actual number. The CDC has provided estimates about the number of 2009 H1N1 cases and related hospitalizations and deaths.
