Skip to content

Cold, Flu, & Cough Health Center

H1N1 Swine Flu Less Severe Than Feared

Swine Flu No More Deadly Than Seasonal Flu, but Victims Much Younger
Font Size
A
A
A
By
WebMD Health News
Reviewed by Louise Chang, MD

Dec. 7, 2009 – H1N1 swine flu won't be as severe as was feared, but the pandemic is nothing to sneeze at, new predictions suggest.

When the fall/winter wave of H1N1 swine flu is over, it will have been no more severe than an average flu season, predict Harvard researcher Marc Lipsitch, DPhil, and colleagues from the U.K. Medical Research Council and the CDC.

"The good news is that ... the severity of the H1N1 flu may be less than initially feared," Lipsitch says in a news release.

There are some big asterisks next to that prediction:

  • Most of the deaths and hospitalizations in a typical flu season are elderly people. Most of those killed or hospitalized in the H1N1 swine flu pandemic are children and young adults.
  • Deaths attributed to seasonal flu include heart attacks, strokes, and other fatal conditions triggered by the flu. Nearly all deaths attributed to H1N1 flu are due to flu or to bacterial complications of flu.
  • The new predictions would be four or five times higher in populations without access to mechanical ventilation or intensive care.
  • All bets are off if the H1N1 swine flu shifts to older populations.

Even so, the new numbers are cause for relief if not for celebration. Before the 2009 H1N1 swine flu came along, planners were preparing for a pandemic with a case/fatality ratio of 0.1% -- that is, for one death in every 1,000 symptomatic infections.

The Lipsitch team now calculates that the H1N1 swine flu has a case/fatality ratio no higher than 0.048% -- and maybe seven to nine times lower, depending on the methods used for calculation.

"This is a serious disease," Lipsitch says in the news release. He noted that between one in 70 and one in 600 people who fall ill with H1N1 swine flu will be hospitalized.

The CDC has been careful not to characterize the severity of the 2009 H1N1 pandemic. The new predictions are very much in line with CDC's working estimates, says Beth Bell, MD, MPH, associate director for science at the CDC's immunization and respiratory disease center.

"This study sends the message that this is primarily a young person's disease and highlights the importance of taking advantage of this window of opportunity to get the vaccine and take preventive measures," Bell tells WebMD. "While most people who get this illness do OK, it can be very severe -- and the severity is concentrated in younger people."

Today on WebMD

hot toddy
15 tips to help you feel better.
man sneezing into elbow
Do echinacea and vitamin C really help a cold?
 
teen girl coughing
Get a good night’s rest with these remedies.
elder berry
Eat these to fight colds, flu, and more.
 
Natural Cold Flu Remedies Slideshow
Slideshow
cold weather
VIDEO
 
Allergy And Sinus Symptom Evaluator
Article
Boy holding ear
Slideshow
 

Loaded with tips to help you avoid food allergy triggers.

Loading ...

Sending your email...

This feature is temporarily unavailable. Please try again later.

Thanks!

Now check your email account on your mobile phone to download your new app.

woman receiving vaccine shot
Article
woman with fever
Article
 
Waking up from sleep
Article
woman with sore throat
Slideshow