The nation's top doctors are sounding the alarm about the season's flu virus.
There has been a dramatic increase in cases on influenza in states across the country compared to last year, with widespread flue reported in 41 states, including Indiana, according to the Centers for Disease Control and Prevention.
One strain of the flu is primarily hitting western states, while the rest of the nation is seeing the primary strain.
Experts say this year's flu vaccine seems to be effective, so they are searching for reasons why the season -- which usually peaks in February -- is so severe right now.
Infectious disease specialists think the cause of the big increase in flu sufferers this year might be due to the drier air, which allows the virus to spread farther than when the air is heavy and moist.
While the flu season is the worst in 10 years, experts say one way to avoid it is to get a flu shot.
More: CDC flu information