CDC swine flu update, Jan 23
CDC H1N1 Flu Website Situation Update, January 23, 2010
Key Flu Indicators
Each week CDC analyzes information about influenza disease activity in the United States and publishes findings of key flu indicators in a report calledFluView. During the week of January 10-16, 2010, all key indicators, except for one, declined compared to the previous week. Below is a summary of the most recent key indicators:
- Visits to doctors for influenza-like illness (ILI) nationally decreased again this week over last week. Visits to doctors for ILI are low in 9 of the 10 U.S. regions. Region 9 had a small decrease in visits to doctors for ILI, but activity is still elevated.
- Overall cumulative hospitalization rates for the 2009-10 influenza season have leveled off in all age groups and very few 2009 H1N1-laboratory confirmed hospitalizations were reported by states during the week ending January 16.
- The proportion of deaths attributed to pneumonia and influenza (P&I) based on the 122 Cities Report increased over the previous week and is higher than expected for this time of year. This increase in P&I is thought to result from an increase in reports of pneumonia-associated deaths in older people. These deaths are not necessarily related to flu illness. In addition, another nine flu-related pediatric deaths were reported this week: three of these deaths were associated with laboratory confirmed 2009 H1N1, four were associated with an influenza A virus for which the subtype was undetermined, one was associated with an influenza A (H3) virus infection, and one was associated with an influenza B virus infection. The influenza A (H3) and B deaths reported this week occurred during the 2008-09 influenza season, bringing the total number of reported pediatric deaths that season to 132. Since April 2009, CDC has received reports of 307 laboratory-confirmed pediatric deaths: 258 due to 2009 H1N1, 47 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. CDC has providedestimates about the number of 2009 H1N1 cases and related hospitalizations and deaths.
- No states reported widespread influenza activity. Seven states continue to report regional influenza activity. They are: Alabama, Georgia, Maine, Nevada, New Jersey, South Carolina, and Virginia.
- Almost all of the influenza viruses identified so far continue to be 2009 H1N1 influenza A viruses. These viruses remain similar to the virus chosen for the 2009 H1N1 vaccine, and remain susceptible to the antiviral drugs oseltamivir and zanamivir with rare exception.
*All data are preliminary and may change as more reports are received.