Doctors say we're entering the worst flu season in a decade, Boston's mayor has declared a public health emergency, and Chicago hospitals are having to turn away sick people. So we should panic, right? Not yet, according to recent flu epidemics. With particularly virulent strains reemerging and emergency room admissions spiking, let's contextualize this flu season by seeing how it stacks up to past outbreaks. 

Time of onset

This is the earliest flu season onset in a decade, reports ABC News' Alex Perez reports. This bout of the flu has arrived a full four months earlier than 2009's outbreak of the H1N1 "swine flu" virus, undoubtedly the worst flu epidemic to hit the U.S. in recent memory — and much, much worse than this year's is expected to be. That saga began in late April, well into spring. Most flu seasons kick in around mid-January, but this year's flu season started snowballing towards the end of December. 

Strain types

This flu season brings back the H3N2 variety of influenza, a strain that brings on stronger symptoms than common flu strains — and sticks around longer. The strain was prevalent in 2004, which saw elevated death rates from the flu. Dr. William Hanage, associate professor of epidemiology at the Harvard School of Public Health, admits that "this is a bad year," but also says that an H3N2 pandemic doesn't appear to be as severe a threat as 2009's H1N1 outbreak. And the good news is that these strains are well-matched by current vaccines. However, only 37 percent of Americans got a flu shot this season and it's only effective in 60 percent of people. 

Emergency room admissions

Reports of Chicago hospitals being so overwhelmed that they've had to turn some flu patients away may sound scary. And admission rates are undoubtedly higher than usual — four percent of Boston's doctor visits are flu-related right now, up from the usual one percent. But it'll take a lot more admissions to reach levels from the 2009 outbreak. CDC researchers calculate that as much as 1 in every 100 people visited hospital emergency wings during that pandemic.

Search engine inundation

The Atlantic Wire's Esther Zuckerman noted earlier that Google Flu Trends is getting more traffic than it's ever seen over its six-year existence. People started frantically searching their flu symptoms sooner in 2009, but they didn't reach anywhere near the critical mas gathering now. 

Death toll

Eighteen children have died from the flu so far this season, according to the CDC. But those numbers are only accurate up to December 29th. So far, it's too soon to know whether the death toll  will eclipse that of the 2009 H1N1 outbreak, which claimed somewhere between 8,870 and 18,300 lives.