# 4467
Influenza Activity in the United States continues well below what might be normally expected this time of year, as shown by this week’s FluView report.
P&I mortality has risen slightly in the latest reporting week, barely exceeding the epidemic threshold. Despite reports last week of a spike in flu hospitalizations in Georgia, ILI (influenza-like-illness) rates nationally have declined from the previous week.
We are also seeing a continuing shift in Asia and Europe towards more influenza B, and less pandemic H1N1. That trend has not surfaced in the United States as yet.
First, a look at some of the highlights of this week’s FluView report, then a snapshot of influenza from around the world.
2009-2010 Influenza Season Week 12 ending March 27, 2010
All data are preliminary and may change as more reports are received.
Synopsis:
During week 12 (March 20-27, 2010), influenza activity remained at approximately the same levels as last week in the U.S.
- 97 (3.5%) 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.
- Approximately 98% of all subtyped influenza A viruses reported to CDC were 2009 influenza A (H1N1) viruses.
- The proportion of deaths attributed to pneumonia and influenza (P&I) was slightly above the epidemic threshold..
- One influenza-associated pediatric death was reported and was associated with 2009 influenza A (H1N1) virus infection.
- The proportion of outpatient visits for influenza-like illness (ILI) was 1.6%, which is below the national baseline of 2.3%. One of 10 regions (Region 9) reported ILI above its region specific baseline.
- No states reported widespread influenza activity. Three states reported regional influenza activity. Puerto Rico and seven states reported local influenza activity. The District of Columbia, Guam and 30 states reported sporadic influenza activity. Ten states reported no influenza activity, and the U.S. Virgin Islands did not report.
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 12, 7.9% of all deaths reported through the 122-Cities Mortality Reporting System were due to P&I. This percentage was slightly above the epidemic threshold of 7.8% for week 12.
Influenza-Associated Pediatric Mortality
One influenza-associated pediatric death was reported to CDC during week 12 (New York City) and was associated with 2009 influenza A (H1N1) virus infection. This death occurred during week 9 (the week ending March 6, 2010).
The chart below trails the above data by one week (represents week 11), but shows that influenza B – while on the decline in the United States – is rising in places like China, Japan, and Europe.
