# 8130
While much has been made in the media over the past couple of weeks regarding the `Return of Swine Flu’, the truth is that pH1N1 has been with us since 2009, albeit at fairly low levels over the past 3 years.
Last year, North America’s flu season was dominated by H3N2, and those over the age of 65 were the hardest hit (see 2013 CDC FluView Week 2 & CDC Media Briefing), while the year before that we saw the mildest flu season in 3 decades (see CDC: The Close Of A Mild Season).
This year, the 2009 H1N1 virus is by far, the dominant strain.
And as we saw in 2009 when this virus first emerged, it tends to infect and sicken a younger demographic than we usually see with seasonal flu strains. Understandably, when previously healthy, young and middle-aged adults end up in the hospital with severe influenza, that tends to grab everyone’s attention.
With triple caveats that reporting to the CDC often lags during the holidays, the true severity of last year’s flu season was only really apparent by mid-January, and that there remains a lot of time left for this year’s flu to fully fulminate, the graphic at the top of this post compares the CDC’s FluView Reports for week 52 for this year and last.
Compared to last year, this flu season shows:
- Flu is widespread in 25 states this year vs. 41 states at this time last year
- Number of positive influenza specimens tested by the CDC: 1711 this year vs. 2961 this time last year
- pH1N1 among positive samples running 54.9% vs 1.1% this time last year
- And most dramatically, this year’s Influenza-Associated Hospitalizations are running about 12 per 100,000 (often a trailing indicator, and subject to revision) this year vs. 52 per 100,000 for those over the age of 65 this time last year.
- Additionally, this year those aged 0-4, 65+, and 50-64 are clustered at the top of those hospitalized, while adolescents and young adults are less affected.
While some in the media have tried to paint this year’s flu as `unusual’ or `mysterious’, this is, quite frankly, the pattern we would expect with pH1N1; a skewing towards younger patients, and occasionally very severe (and sometimes fatal) infection.
Despite a lackadaisical attitude by many, influenza kills thousands of people in the United States every year. It should not be taken lightly, even during a `mild’ flu season.
With the bulk of the flu season still ahead, it isn’t too late to get a flu shot. Most years they can provide moderate protection, and they have an excellent safety record.
Here are some excerpts from this week’s FluView report.
2013-2014 Influenza Season Week 52 ending December 28, 2013
All data are preliminary and may change as more reports are received.
Synopsis:
During week 52 (December 22-28, 2013), influenza activity continued to increase in the United States.
- Viral Surveillance: Of 6,419 specimens tested and reported by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories during week 52, 1,711 (26.7%) were positive for influenza.
- Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the epidemic threshold.
- Influenza-Associated Pediatric Deaths: Two influenza-associated pediatric deaths were reported.
- Influenza-associated Hospitalizations: A cumulative rate for the season of 5.8 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 4.3%, above the national baseline of 2.0%. All 10 regions reported ILI at or above region-specific baseline levels. Twenty states experienced high ILI activity; eight states and New York City experienced moderate ILI activity; six states experienced low ILI activity; 16 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
- Geographic Spread of Influenza: The geographic spread of influenza in 25 states was reported as widespread; 20 states reported regional influenza activity; Puerto Rico and three states reported local influenza activity; the District of Columbia and two states reported sporadic influenza activity, and the U.S. Virgin Islands and Guam did not report.
With students returning to school, and many people returning to work after a holiday break, the opportunities for spreading the flu will improve over the coming days. We should not be surprised to see these numbers climb over the next few reporting weeks.
A reminder that it doesn’t take a novel, or pandemic flu strain ruin your entire day.
With flu season in full swing, in addition to getting a flu shot, is particularly important to maintain good flu hygiene right now. The CDC recommends:
- Wash your hands often with soap and water or an alcohol-based hand rub.
- Avoid touching your eyes, nose, or mouth. Germs spread this way.
- Try to avoid close contact with sick people.
- Practice good health habits. Get plenty of sleep and exercise, manage your stress, drink plenty of fluids, and eat healthy food.
- Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
- If you are sick with flu-like illness, stay home for at least 24 hours after your fever is gone without the use of fever-reducing medicine.
