The FluView report for week three is out, and the news includes eight pediatric deaths and the continued spike in P&I mortality rates (Pneumonia & Influenza) as reported by 122 U.S. Cities, which reached 9.8%.
P&I mortality is typically a trailing indicator of the flu season, and so while some regions are seeing decreases in influenza activity, the number of deaths can continue to rise for several weeks.
Some highlights from this week’s report:
All data are preliminary and may change as more reports are received.
During week 3 (January 13-19), influenza activity remained elevated in the United States, but decreased in some areas.
- Viral Surveillance: Of 11,984 specimens tested and reported by collaborating laboratories, 3,129 (26.1%) 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 influenza-associated pediatric deaths were reported.
- Influenza-Associated Hospitalizations: A cumulative rate for the season of 22.2 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported. Of all hospitalizations, 50% were among adults 65 years and older.
- Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 4.3%; this is above the national baseline of 2.2%. All 10 regions reported ILI above region-specific baseline levels. Twenty-six states and New York City experienced high ILI activity; 14 states experienced moderate activity; 9 states experienced low activity; 1 state experienced minimal activity, and the District of Columbia had insufficient data.
- Geographic Spread of Influenza: Forty-seven states reported widespread geographic influenza activity; 2 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.
The eight pediatric deaths did not all occur during the reporting week, as the following summary explains.
Eight influenza-associated pediatric deaths were reported to CDC during week 3. Two were associated with influenza A viruses for which the subtype was not determined and occurred during week 1 (week ending January 5, 2013), and six were associated with influenza B viruses and occurred during weeks 43, 46, 50, 52, and 3 (weeks ending October 27, November 17, December 15 and 29, 2012 and January 19, 2013).
A total of 37 influenza-associated pediatric deaths have been reported during the 2012-2013 season from New York City  and 18 states (Arkansas , Colorado , Florida , Indiana , Kansas , Maine , Massachusetts , Michigan , Minnesota , Nebraska , New Jersey , New York , Ohio , South Carolina , Tennessee , Texas , Washington , and Wisconsin ). Additional data can be found at http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html.
The age group most impacted by this year’s flu season continues to be those over the age of 65, who account for half of all those hospitalized.
The last time the CDC charted P&I 122 City Mortality Rates this high was in Dec-Jan of the 2003-04 flu season (see chart below) – that like this one – began early and has been categorized as `moderately severe’ by the CDC (cite 2003 - 04 U.S. INFLUENZA SEASON SUMMARY*)
2003-04 Flu Season P&I Mortality
As a historical note, the P&I mortality rate reached 11% across 122 cities during the 3rd week of January, 2000.
So while elevated, this week’s P&I mortality rate is not unprecedented.
Last week, 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 early treatment with Tamiflu (oseltamivir) for high risk patients