Credit CDC FluView
# 8217
Flu season remains in full swing in the Northern Hemisphere, with the pH1N1 virus causing the bulk of the misery across the United States. Unlike seasonal H3N2 – which usually hits those over the age of 65 the hardest – pH1N1 often severely impacts younger age groups.
And the evidence thus far is that adults under the age of 65 are being hit particularly hard by this year’s flu season.
2013-2014 Influenza Season Week 3 ending January 18, 2014
All data are preliminary and may change as more reports are received.
Synopsis:
During week 3 (January 12-18, 2014), influenza activity remained high in the United States.
- Viral Surveillance: Of 12,108 specimens tested and reported during week 3 by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories, 2,793 (23.1%) 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 season-cumulative rate of 17.0 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported.
- Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 3.4%, above the national baseline of 2.0%. All 10 regions reported ILI above region-specific baseline levels. Thirteen states experienced high ILI activity; seven states and New York City experienced moderate ILI activity; 15 states experienced low ILI activity; 15 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
- Geographic Spread of Influenza: The geographic spread of influenza in 41 states was reported as widespread; eight states and Puerto Rico reported regional influenza activity; the District of Columbia reported local influenza activity; one state and Guam reported sporadic influenza activity, and the U.S. Virgin Islands reported no influenza activity.
A description of surveillance methods is available at: http://www.cdc.gov/flu/weekly/overview.htm
A few graphs from today’s report, to help compare this year to the last couple:
For the second week in a row the P&I mortality rate has been above the epidemic threshold. It is at a hefty 8.1% in week three, but less than the near-record 9.8% in week three a year ago.
Pneumonia and Influenza (P&I) Mortality Surveillance
During week 3, 8.1% of all deaths reported through the 122 Cities Mortality Reporting System were due to P&I. This percentage was above the epidemic threshold of 7.2% for week 3.
Pediatric deaths, meanwhile, are lower than this time last year, and considerably below the numbers we saw in the 2009-10, and 2010-11 flu seasons. These are, however, often lagging indicators and we often get `caught up’ with cases later in the season.
And one last graph shows hospitalizations by age cohorts with confirmed influenza, and those over the age of 50, and under the age of 4, make up the majority of these cases while those aged 5-49 are the least impacted.
Last year, the hospitalization rate for those aged > 65 in week three was triple that of what we are seeing this season.
While some states are reporting a decrease in influenza activity, others continue to rise, and we are apt to see significant flu activity for weeks to come.
Regardless of the strain of flu in circulation, you are much better off avoiding infection rather than treating it. So while it may only provide moderate protection, getting the flu shot each year is cheap insurance.
That, and following good flu hygiene practices (covering coughs, washing hands frequently, staying home when sick, avoiding close contact with those who are sick), are your best defense against our yearly flu epidemic.
