Influenza rare this season


Do you know anyone who had influenza this past year? Chances are you do not. Sure, plenty of people had the “stomach flu” with vomiting and diarrhea, otherwise known as gastroenteritis. Some people had colds, and others had COVID-19. But cases of influenza this season have been exceptionally low.

Starting a year ago, when someone came to my clinic with symptoms of influenza, including fevers, chills, muscle aches or respiratory symptoms, we tested for both COVID-19 and for influenza. At first, every COVID-19 test was negative while many influenza tests were positive. However, with social distancing, mask wearing, washing hands and people staying home when they were sick, influenza cases in South Dakota plummeted faster than I have ever seen. 

The charts put out by the South Dakota Department of Health speak for themselves. Every week they send out the latest influenza statistics and compare them to past years. The number of influenza cases forms something like a bell curve or mountain which peaks in South Dakota typically during the third week of February and then tapers down again. This year that line of cases for 2020-2021 is essentially flat, and this week we saw a slight increase in cases which will hopefully only form a small bump on the chart as opposed to a mountain.

Usually there are well over 2,000 confirmed cases of influenza in South Dakota each year, with almost 15,000 confirmed in last year’s season. In a normal year, many more people have influenza but go unrecorded because they are not tested. For this current influenza season, many people are being tested for COVID-19 and influenza at the same time. Despite thousands of tests, there have been only 55 confirmed cases of influenza in the state through the third week of February.

Over the last decade, influenza claimed an average of 32 lives each year in South Dakota. The worst season was 2017-2018 when 73 people died, and the fewest deaths occurred in 2015-2016 when nine people died. We know that this past year, COVID-19 claimed the lives of more than 1,850 people in South Dakota. COVID-19 still managed to thrive even while influenza withered. The biggest reason is because COVID-19 is more contagious than influenza. Vaccinations and past immunity to influenza also help reduce its occurrence. 

We cannot stress how important and helpful everyone’s efforts over this last year have been toward keeping the numbers of COVID-19 down as much as we could to “flatten the curve” and avoid a catastrophe with everyone getting sick at once. We are not out of the woods yet, but we are getting closer. As far as influenza goes, it would appear that washing our hands, staying home when sick, social distancing and wearing masks have drastically helped to minimize the spread.

Andrew Ellsworth, M.D. is part of The Prairie Doc® team of physicians and currently practices family medicine in Brookings, South Dakota. For free and easy access to the entire Prairie Doc® library, visit and follow Prairie Doc® on Facebook featuring On Call with the Prairie Doc® a medical Q&A show streaming on Facebook and broadcast on SDPB most Thursdays at 7 p.m. central.


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