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Influenza (Seasonal Flu)

Seasonal Influenza (Flu)

Influenza is a contagious, upper-respiratory disease caused by different strains of influenza viruses. While many people use the imprecise term "flu" to describe 24 or 48 hour bouts of illness, real influenza can interfere with normal daily activities for as long as a week.

Influenza is not a minor inconvenience. As many as 200,000 Americans are hospitalized because of it each year, and as many as 36,000 die of the disease or complications associated with it.

Children under age 1, adults 65 or older and people suffering from certain medical conditions are at a higher risk of serious complications.


2017-2018 Influenza Season Update (Updated every Friday. Note that like CDC, influenza reporting is always 1 week behind.)

Montana 2016-17 Final Influenza Season Summary


Is it a cold or is it influenza? Posters available for download (click on an image to download a printable version).

   cold v flu 2      cold versus flu poster 1


Girl with a cold Vaccine Posters Information for healthcare providers Montana Influenza Activity Map U.S. flu activity