Each week CDC analyzes information about influenza disease activity in the United States and publishes findings of key flu indicators in a report called FluView. During the week of January 17-23, 2010, most key flu indicators remained about the same as during the previous week. Below is a summary of the most recent key indicators:
- Visits to doctors for influenza-like illness (ILI) nationally are low.
- 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 23.
- 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 five flu-related pediatric deaths were reported this week: four of these deaths were associated with laboratory confirmed 2009 H1N1, and one death was associated with an influenza A virus for which the subtype was undetermined. Since April 2009, CDC has received reports of 312 laboratory-confirmed pediatric deaths: 262 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 provided estimates about the number of 2009 H1N1 cases and related hospitalizations and deaths.
- No states reported widespread influenza activity. Five states reported regional influenza activity. They are: Alabama, Georgia, New Jersey, South Caroline 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.