There’s been no dearth of stories about this flu season being especially bad, and we’re still (probably) far from the end. So, at least at this point, just how bad is this flu season, anyway?
For some insight, we turned to the CDC’s FluView, which tracks a variety of indicators at the national and more local levels. Let’s get the headline out of the way first: Overall, it’s not pretty. In the second week of January, some 6.3% of patients visited a doctor with influenza-like illness (ILI). That’s well above the 2.2% national baseline, and the highest weekly rate recorded since the 2009 H1N1 “swine flu” pandemic. (Mousing over the lines will show additional information.)
It’s the highest rate recorded at this time of year in the past 15 years, two full percentage points ahead of its closest competition.
The problem was especially bad in Texas and the surrounding states that make up HHS Region 6. There, 12.6% of patients reported ILI. The next highest region was in the Midwest, comprising Iowa, Kansas, Missouri and Nebraska.
While that information is meaningful, it may overstate the severity of the problem. The hospitalization rate for influenza in week 2 was 31.5 per 100,000. That’s obviously not ideal, but it is lower than even the 2014-15 season, when the rate had already reached 48.4 before eventually peaking at 64.2.
There’s also not much evidence in the report to support the idea of ineffective vaccines. The majority of the influenza viruses the CDC collected at the end of last year were characterized as similar to the cell-grown reference viruses representing the 2017–18 flu vaccine viruses. However, these data wouldn’t reflect small but significant antigenic differences between the egg-grown viruses used in vaccines versus the viruses circulating out in the world, which this year are thought to have diminished the vaccine’s effectiveness.
All that aside, the strain of caring for patients impacted is all too real, as MedPage Today‘s Molly Walker reported Tuesday.
“The difficulties the healthcare system is currently experiencing coping with this strain of flu doesn’t bode well for any future influenza pandemic,” Amesh Adalja, MD, of Johns Hopkins Center for Health Security in Baltimore, told MedPage Today.