A spot-on column in CIDRAP Business Source [subscription] by Center for Infectious Disease Research and Policy’s (CIDRAP) Director, Mike Osterholm, reminded me to say something I’ve wanted to say for a long time. We should banish the word “mild” from the influenza lexicon. There’s no such thing as a mild case of influenza, any more than there are “mild” auto accidents. There are cases that for reasons we don’t understand don’t make you very sick (or sick at all), and there are cases that can lay you lower than you ever want to be, including six feet under. What Osterholm does with great cogency is put paid to the idea this is a mild pandemic. His reasons will be familiar to readers here, but he says them extremely well.
Both Osterholm and we find CDC’s most recent estimates (November 14) of about 10,000 deaths, 47 million infections and over 200,000 hospitalizations “credible and thoughtful.” To compare the oft quoted number of 36,000 excess deaths from seasonal flu to this 10,000 number is an “apples and oranges” affair. The 36,000 number is an excess mortality figure derived by different and non-comparable methods (see our post here for more details). Here is some of Osterholm’s version:
In that CDC study, only 9,000 of those estimated annual seasonal deaths are due directly to influenza or secondary bacterial pneumonia. The other deaths are among persons who have influenza and who die of events like heart attacks or strokes. If you want a comparison, think of the guy who has a heart attack while snow blowing his driveway after a large snowstorm and whose death is labeled “storm-related.”
More important, though, is what we pointed out early on. It’s not just the number of deaths but the pattern of illness in the population, flu’s descriptive epidemiology:
More than 90% of the estimated seasonal influenza deaths occur in the elderly, who in many instances have existing serious health conditions that mean their deaths may not be far off, regardless of their influenza illness. We all realize that death is inevitable, and, as a public health practitioner, I find that this mad race to eliminate the top 10 causes of death is not always well thought through. If we were to accomplish such a goal, there would be 10 new leading causes of death, and I’m not so sure some of those would be better than the current ones. But I think we can all agree that “early deaths”?or those that occur well before our elderly years ?just shouldn’t happen. The way we count influenza mortality, an influenza-related death in an 87-year-old person with advanced Alzheimer disease is the same as the death of a 22-year-old otherwise perfectly healthy pregnant woman. Both deaths are equally tragic, but any reasonable person would agree they are not equivalent public health outcomes.
Of the estimated 9,820 deaths:
- 1,090 (11%) have occurred in children 0-17 years of age
- 7,450 (76%) in people 18-64 years of age
- 1,280 (13%) in people over 65 years of age
This age distribution differs considerably from what we see with seasonal influenza. (Dr. Michael Osterholm, Featured article CIDRAP BUsiness Source; subscription required)
Which brings me back to the issue of “mild” flu and mild pandemics. While this pandemic is not 1918 (for which we can be grateful, although no one knows what prevents this or any other pandemic from repeating that catastrophe), it is still pretty bad, already producing more estimated hospitalizations than seasonal flu and we aren’t even into the heart of flu season yet:
It’s challenging our healthcare system unlike any previous seasonal influenza season over the past 30 years. That makes it hard for me to call this a “mild? pandemic. I just don’t believe the term works.
Yes, there are mild, moderate, or severe influenza illnesses on an individual basis. But how do we describe a pandemic that hits a limited group of people really hard and causes only “routine influenza” for most others?
Whatever you describe it, I’m with Osterholm. Don’t call anything connected with flu, mild. Most flu infections don’t have dire consequences, but a significant number do. And we never know who is going to win the lottery. The convergence in our views extends to the same analogy: automobile accidents. As we’ve noted several times, it doesn’t make much sense to call any encounter with several tons of moving steel “mild.” It may be an encounter that produces little or no damage, but that’s luck. Anyone who’s gotten the repair bill for what can happen when hit by another car going only 5 miles per hour won’t consider the encounter “mild.” More importantly, any such encounter has the potential to be a catastrophe and the really bad ones are often just plain dumb luck. Mostly we don’t have such terrible luck. Yet even a fender bender can be expensive or result in minor injuries and be emotionally traumatic as well as result in lost work. Whatever you might be tempted to call an auto accident (minor or a scratch or a fender bender), very few people would be prone to call it “mild.” And whle the number of people killed each year in motor vehicle accidents is roughly the same as seasonal flu, we don’t usually think of our nation’s annual highway death toll of 40,000 as “mild” either. Its age distribution isn’t too different than pandemic flu’s either, the source of much anxiety to any parent whose child has just gotten their driver’s license.
It’s not just that “mild” is an inapt word. It is an inapt and dangerous idea. It is based on comparing total deaths in flu seasons with each another, not with the public health toll they exact. It is worse than a word not conveying the proper seriousness. It sends a message that itself has consequences, promoting a lack of urgency about taking rational public health measures like vaccination.
That’s especially pertinent this year when we don’t yet know what the usual flu season (January to March) will bring, either with seasonal flu or a recrudescence (“wave 3″) of swine flu. As Osterholm points out, even with available vaccine now certain in the next few months, we are likely to find ourselves in January with a very large proportion of the population still without immune protection.
After all, what’s the hurry? It’s a mild pandemic.