Readers of Real Answers with Dr. Arthur Lavin will remember that nearly every posting on the influenza virus reminds us that this is a virus that mysteriously appears every year around the same time, and just as strangely, disappears every year in an equally predictable manner.
The Time of the Yearly Influenza Virus Epidemic
The month the annual influenza epidemic tends to begin is December, and the month it ends tends to be March.
This winter’s epidemic of influenza virus is arriving right on time, many states across the US are now reporting early signs of the return of the influenza virus. You can actually track the appearance of the virus for this year’s epidemic, and really every year going back to 2003 here: https://www.cdc.gov/flu/weekly/index.htm#ILIMap
Just go to the colorful US map, select a year you want to see, and hit Play.
As of last week, Ohio is showing some influenza virus activity but not much. Most states have sporadic activity, with more widespread influenza virus activity across the South.
But this report means that the epidemic has lit, and over the next few weeks, influenza viruses will be soaking nearly every city, town, and village across the entire United States.
Influenza viral infections will raging across the whole country throughout that time, through January, February, and March. If we are lucky almost none in April, and even if not so lucky, the epidemic will be thoroughly ended by May for sure.
Now, most of us will wonder, how is it possible the influenza epidemic is only really starting now? Hasn’t everyone been terribly sick with colds and flus for months already?
Colds and Flus aren’t All from the Influenza Virus
We know that we in NE Ohio have been afflicted with a tremendous load of colds, really since the end of September. October was a terrible month of terrible colds, stomach flus, and respiratory flus. So many of us were sick, and so many got sick again in November and already again in December. It has been truly awful.
But these viruses, until very recently, and with rare exception, have not had anything to do with the influenza virus epidemics we get every winter. Our influenza virus epidemic for 2019-2020 is only just now arriving, has barely really hit.
This makes the point as dramatically as possible. Think of all the colds and flus you, your families, and your schools have suffered since school began, and pretty much none of them were from the flu epidemic! There is no doubt, most viral infections, even in the winter, are NOT due to the influenza virus.
In fact we know that number. Even in just winter, about 2/3 colds and flus are NOT from the influenza virus.
Of course, that means about 1/3 of our winter colds and flus are from the influenza virus, and these occur typically December-March.
How Bad was the Influenza Epidemic of 2018-2019
The years of comparison the CDC presents go back to 2009. Comparison, the epidemic of 2018-2019 was more moderately severe. Not as bad as some years, but about the third most severe over the last 10 years. One distinction for the influenza epidemic last year was that it had two peaks. There were there was a flare of influenza viral infection around New Year’s Day and then again in early March. But just like other years the influenza virus was around for the same period, as discussed above, December through March, last year was no exception.
The percentage of people with colds who had influenza virus cause their infection at any point in time was higher in 2017-2018 than the years 2009 to 2017. But not by much. A typical year saw 2-6% of people with colds infected with the influenza virus at any one point in time. In 2018-2019 that number peaked at 5%. Not much different than the peaks of 5% in 2016-2017, and 6% in 2014-2015.
Perhaps the most dreadful number tracked is the number of children who die each influenza epidemic. The CDC only started tracking that number 4 years ago.
In the past 4 epidemics, the total number of children who we know died from infection from the influenza virus were, in order, 110, 187, 143. If there are 100 million children in the US and one-third or so of winter colds and flus are from influenza, one could estimate roughly 30 million or so children will have influenza virus infection each winter. The fact that only 185 children died, at the peak year, demonstrates that, very thankfully, influenza virus infection in healthy children is not a dangerous infection. Most deaths from this virus occur towards the end, not beginning of life, keep in mind the CDC estimates that about 80,000 people die from this virus every year, the proportion of them that are children is small, again, thankfully.
Should You Get the Flu Shot?
We say yes.
For several reasons:
- It gets rid of 1/3 of all winter colds and flus. I personally hate being sick, I don’t know many who like it. Getting the flu shot will rid you and your family of 1/3 of all winter colds, we think that is reason enough.
- Although actual tragedy is rare in childhood from the typical influenza virus infection, it does happen, why take the chance? The shot drops the chance of this too.
- The flu shot is safe. There is no live virus in the flu shot, so it is physically incapable of giving anyone the flu.
- The most common form of influenza virus infections are seasonal and in the US that means December through March. This year is no exception.
- So all the colds from when school began to now have been almost all NOT influenza, but some other virus.
- The 2019-2020 influenza virus is showing up right on time, in December, and the CDC shows it is indeed appearing now. It will be everywhere by New Years and all over the place through March.
- Influenza virus infections tend, overwhelmingly, to be not so dangerous to most healthy children, but can result in tragedy rarely.
- We recommend the flu shot, it prevents lots of illness, and can prevent tragedy.
Of course, we all hope this year’s epidemic is mild, and whatever the virus does, we are here to help.
To your health and happy holidays,
Dr. Arthur Lavin