Many folks were probably surprised by reports that this has been the longest flu season in ten years.
After all, just about everything about this year’s flu season has likely seemed mild compared to last year.
“There have been 21 straight weeks of elevated flu season in the U.S., making the current 2018-2019 flu season the longest in ten years.”
CNN
But here we are.
Has This Really Been the Longest Flu Season in a Decade?
What does it really mean to have 21 straight weeks of elevated flu season?

Where is it elevated and by how much?
“Influenza-like-illness levels have been elevated for 21 weeks this season, breaking the previous record of 20 weeks set during the 2014-2015 flu season.”
Situation Update: Summary of Weekly FluView Report Week 15
It’s likely that the media reports have been generated by a statement in the latest Weekly FluView Report that influenza-like-illness levels have been elevated for a little longer than usual this season.
What does that mean?
Well, influenza-like-illness levels are the proportion of outpatient visits for influenza-like illness (ILI), or basically, how many people are going to the doctor with flu symptoms. Once we get above the national baseline of 2.2%, we know that flu season has started.
“The proportion of outpatient visits for influenza-like illness (ILI) decreased to 2.4%, but remains above the national baseline of 2.2%. Seven of 10 regions reported ILI at or above their region-specific baseline level.”
Situation Update: Summary of Weekly FluView Report Week 15
And it ends when we get back below 2.2%.

What’s missing in the talk of the longest flu season, is that it doesn’t tell you much about the severity of the flu season. For example, the peak ILI this year was well below that of last year.
And flu season doesn’t start and end at the same time all over the country.
The bottom line? This has been an average flu season and a lot of people still died, including at least 91 children.
So whether it is a long or short flu season, severe or mild, get a flu vaccine and be protected.
More on the Longest Flu Season
- VAXOPEDIA – Understanding Flu Season
- VAXOPEDIA – Can Flu Shots Cause the Flu?
- VAXOPEDIA – I’m Not Anti-Vaccine, I Just Don’t Believe in Flu Shots
- VAXOPEDIA – Is This Year’s Flu Vaccine Working?
- VAXOPEDIA – Who Dies from the Flu?
- VAXOPEDIA – How Effective Is the Flu Vaccine?
- VAXOPEDIA – Why Do Some Folks Wear a Mask During Flu Season?
- VAXOPEDIA – I Refuse to Listen to Bad Advice About Flu Shots, and I Won’t Apologize for It
- VAXOPEDIA – Three Reasons to Skip a Flu Shot This Year
- VAXOPEDIA – Are Your Kids at High Risk for Flu Complications?
- Family Stories – Families Fighting Flu
- CDC – Situation Update: Summary of Weekly FluView Report
- CDC – Overview of Influenza Surveillance in the United States
- CDC – Influenza-Like Illness (ILI) Activity Level Indicator Determined by Data Reported to ILINet
- CDC – Laboratory-Confirmed Influenza Hospitalizations
- CDC – Weekly Influenza Activity Estimates Reported by State and Territorial Epidemiologists
- CDC – Influenza-Associated Pediatric Mortality Surveillance System
- CDC – Frequently Asked Flu Questions 2018-2019 Influenza Season
- CDC – Early-Season Flu Vaccination Coverage–United States, November 2018
- CDC – Current & Past Flu Seasons
- CDC – Past Pandemics