#6902
The story of this year’s flu season continues to revolve around the heavy toll the H3N2 virus is talking on the elderly population, but with 8 new pediatric deaths reported for the second week in a row, other age groups are being hit as well.
This season is also marked by an unusually early appearance of the flu, and a march of ILI activity across the nation from the south and east to the west.
Some excerpts from today’s FluView Report.
2012-2013 Influenza Season Week 4 ending January 26, 2013
All data are preliminary and may change as more reports are received.
Synopsis:
During week 4 (January 20-26), influenza activity remained elevated in the United States, but decreased in some areas.
- Viral Surveillance: Of 10,581 specimens tested and reported by collaborating laboratories, 2,701 (25.5%) were positive for influenza.
- Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was above the epidemic threshold.
- Influenza-Associated Pediatric Deaths: Eight pediatric deaths were reported.
- Influenza-Associated Hospitalizations: A cumulative rate for the season of 25.9 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported. Of all hospitalizations, more than 50% were among adults 65 years and older.
- Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 4.2%; this is above the national baseline of 2.2%. All 10 regions reported ILI above region-specific baseline levels. Twenty-four states and New York City experienced high ILI activity; the District of Columbia and 13 states experienced moderate activity; 4 states experienced low activity; and 9 states experienced minimal activity.
- Geographic Spread of Influenza: Forty-two states reported widespread geographic influenza activity; 7 states reported regional activity; the District of Columbia and one state reported local activity; Guam reported sporadic influenza activity, and Puerto Rico and the U.S. Virgin Islands did not report.
Although the 122 city P&I mortality rate dropped this week to 9.4%, that is still at a level that – until last week – we hadn’t seen in nearly a decade.
Pneumonia and Influenza (P&I) Mortality Surveillance:
During week 4, 9.4% of all deaths reported through the 122 Cities Mortality Reporting System were due to P&I. This percentage was above the epidemic threshold of 7.4% for week 4.
Influenza-related hospitalizations continue to be heavily skewed towards those over 65, reaching an 116.1 per 100,000 population, accounting for more than half of all hospitalizations.
This last chart shows the flu-related pediatric deaths reported to the CDC over the past four years. The huge spike in 2009-10 due to the emergence of the H1N1 pandemic.
Pediatric deaths and P&I mortality reports are usually trailing indicators, with reports sometimes delayed by several weeks, so we may well continue to see elevated numbers over the next few FluView reports even as the overall level of flu starts to decline.
Two weeks ago, CDC Director Frieden pointed out the heavy toll this flu season is having on the elderly (see CDC Media Briefing), and stressed the importance of seeking early medical treatment, including the use of Tamiflu (oseltamivir) for high risk patients
