Study Shows Why the Flu Likes Winter

Posted on December 6, 2007  Comments (4)

Study Shows Why the Flu Likes Winter:

The answer, they say, has to do with the virus itself. It is more stable and stays in the air longer when air is cold and dry, the exact conditions for much of the flu season.

“Influenza virus is more likely to be transmitted during winter on the way to the subway than in a warm room,” said Peter Palese, a flu researcher who is professor and chairman of the microbiology department at Mount Sinai School of Medicine in New York and the lead author of the flu study. Dr. Palese published details of his findings in the Oct. 19 issue of PLoS Pathogens.

Reading a paper published in 1919 in the Journal of the American Medical Association on the flu epidemic at Camp Cody in New Mexico, he came upon a key passage: “It is interesting to note that very soon after the epidemic of influenza reached this camp, our laboratory guinea pigs began to die.”

Dr. Palese bought some guinea pigs and exposed them to the flu virus. Just as the paper suggested, they got the flu and spread it among themselves. So Dr. Palese and his colleagues began their experiments. By varying air temperature and humidity in the guinea pigs’ quarters, they discovered that transmission was excellent at 41 degrees. It declined as the temperature rose until, by 86 degrees, the virus was not transmitted at all.

The virus was transmitted best at a low humidity, 20 percent, and not transmitted at all when the humidity reached 80 percent. The animals also released viruses nearly two days longer at 41 degrees than at a typical room temperature of 68 degrees.

Very interesting and you can read the actual paper since it is open access: Influenza Virus Transmission Is Dependent on Relative Humidity and Temperature.

Related: I Support the Public Library of ScienceNew and Old Ways to Make Flu VaccinesOpen Access and PLoSDrug-resistant Flu Virus

4 Responses to “Study Shows Why the Flu Likes Winter”

  1. CuriousCat: Study challenges notion of ‘pandemic’ flu
    April 13th, 2008 @ 2:19 pm

    “pandemic-equals-extreme-mortality concept appears to be a generalization of a single data point: the 1918 season, a period in which ‘doctors lacked intensive care units, respirators, antiviral agents and antibiotics’…”

  2. Anonymous
    September 5th, 2008 @ 1:02 pm

    Looks like we need to humidify schools and places of employment to prevent the spread then. Very interesting.

  3. Curious Cat Science Blog » Google Flu Leading Indicator
    November 13th, 2008 @ 8:39 am

    This is an interesting example of finding new ways to quickly access what is happening in the world…

  4. Curious Cat Science Blog » One Sneeze, 150 Colds for Commuters
    December 7th, 2008 @ 9:44 am

    “A single sneeze expels 100,000 droplets of germs into the air at 90mph. Individual droplets get transferred to handles, rails and other areas frequently held or touched…”

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