# 4122
The CDC has posted FluView for week 47, ending November 28th, 2009. The amount of flu activity we are seeing has decreased again for the fifth straight week after four consecutive weeks of sharp gains, but is still higher than normally seen this time of year.
P&I (pneumonia & Influenza) deaths have declined and remain just barely above the epidemic level for this time of year, and 17 pediatric influenza-related deaths were added last week.
While the numbers here in the US, and also in Canada, reflect a winding down of the fall pandemic wave, what lies ahead is less clear. There are almost 5 more months remaining in flu season, and there are a number of possible scenarios (see Waiting For The Other Flu To Drop).
We’ll just have to wait to see. In the meantime, we’ll take any respite we can get.
I’ve excerpted some of the data and graphs below, but follow the link to read it in its entirety.
2009-2010 Influenza Season Week 47 ending November 28, 2009
All data are preliminary and may change as more reports are received.
Synopsis:
During week 47 (November 22-28, 2009), influenza activity continued to decrease in the U.S.
- 956 (15.4%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories and reported to CDC/Influenza Division were positive for influenza.
- Over 99% of all subtyped influenza A viruses being reported to CDC were 2009 influenza A (H1N1) viruses.
- The proportion of deaths attributed to pneumonia and influenza (P&I) was above the epidemic threshold for the ninth consecutive week.
- Seventeen influenza-associated pediatric deaths were reported. Twelve of these deaths were associated with 2009 influenza A (H1N1) virus infection and five were associated with an influenza A virus for which the subtype was undetermined.
- The proportion of outpatient visits for influenza-like illness (ILI) was 3.7% which is above the national baseline of 2.3%. Eight of the 10 regions reported ILI at or above region-specific baseline levels. Regions 6 and 10 reported ILI below their region specific baselines.
- Twenty-five states reported geographically widespread influenza activity, 17 states reported regional influenza activity, the District of Columbia, Puerto Rico and six states reported local influenza activity, and Guam, the U.S. Virgin Islands and two states reported sporadic influenza activity.
U.S. Virologic Surveillance:
WHO and NREVSS collaborating laboratories located in all 50 states and Washington D.C., report to CDC the number of respiratory specimens tested for influenza and the number positive by influenza type and subtype. The results of tests performed during the current week are summarized in the table below.
Pneumonia and Influenza (P&I) Mortality Surveillance
During week 47, 7.2% of all deaths reported through the 122-Cities Mortality Reporting System were due to P&I. This percentage was above the epidemic threshold of 7.1% for week 47. Including week 47, P&I mortality has been above threshold for nine consecutive weeks.
Influenza-Associated Pediatric Mortality
Seventeen influenza-associated pediatric deaths were reported to CDC during week 47 (Arizona [2], California [5], Florida, Indiana [2], Michigan, Minnesota, New York, Ohio, South Dakota, and Texas [2]). Twelve of these deaths were associated with 2009 influenza A (H1N1) virus infection and five were associated with an influenza A virus for which the subtype is undetermined. The deaths reported during week 47 occurred between September 13 and November 21, 2009.
