Earlier this week, Israeli media reported a person who was hospitalized with evidence of both seasonal flu and COVID at the same time. This unvaccinated and pregnant person had mild symptoms and was discharged without any complications.
A person being infected with both the COVID-causing SARS-CoV2 virus and an influenza virus can happen; we just had one such person in our hospital last month whom we treated and discharged without a whole lot of fanfare. However, the Times of Israel made a mundane two-virus story go viral by using a catchy, made-up name of “flurona” and reporting that this is the “first” such case in the country, which some people read as the first case ever.
Several news outlets and internet sites took it from there, with one Web magazine amplifying the anecdotal report into “a new nightmare to keep us awake at night.” Of course, social media was abuzz with anxiety arising from misinformation, such as that flurona was a combined flu and SARS-CoV-2 supervirus. Other people created memes mocking any seriousness attached to either of the infections.
We are in the middle of a raging COVID surge, coupled with flu season. Every respiratory infection that comes through our doors could be one of many things. The way this story was taken out of context is yet another example of the kind of internet-based misinformation that haunts all of us who are trying to fight the real crisis at hand. Physicians and scientists just don’t seem to be able to get the right message across to the public about what is real, what is treatable and what is downright false.
When a worldwide pandemic with over a million and a half new cases each day collides with a seasonal influenza outbreak among a world population largely unvaccinated against either COVID or flu, it is reasonable to find patients who may catch both viruses around the same time. I’m sure many other institutions in the Northern Hemisphere, where the seasonal flu incidence is increasing, are now seeing such anecdotal cases.
The signs and symptoms of flu and COVID are largely similar; this is one of the facts that is often twisted by misinformation campaigners to suggest COVID is simply the flu. Both of these pathogens spread via respiratory droplets or small particles, but they enter cells using different mechanisms. They are not the same thing, and there is no evidence of a combined supervirus.
Practitioners use diagnostic tests that can differentiate between respiratory infections like COVID-19, influenza A and B, and respiratory syncytial virus. We use hundreds of these tests during the high season. The increasing availability of more sensitive combined molecular tests that can diagnose one of these respiratory diseases in a single test with a single sample has improved the reliable identification of these infections.
A meta-analysis of studies reported from the last Northern Hemisphere flu season showed that in people with COVID-19, about 0.8 percent also had flu; in the U.S., this was about 0.4 percent. So, while it’s not the most common co-infection, people can get both viruses at the same time. The small numbers reported in this paper did not suggest any alarming severity of co-infections nor increased mortality.
Another study presented at a recent infectious disease conference from U.S. researchers found that co-infection was rare (0.2 percent) and mortality rates were no different. However, co-infection with influenza did result in more COVID-19 patients having respiratory failure and needing mechanical ventilators. The numbers in these studies are small. There are other studies underway looking at the question of how co-infection with SARS-CoV-2 and flu manifests, but the bottom line is the jury is still out on whether having both infections at the same time is as terrible as some social media posts suggest it could be.
Widespread use of mitigation measures such as masks, social distancing and school closures made the 2020–2021 flu season virtually non-existent, both in the Northern and Southern Hemisphere. However, flu forecasters are anticipating that the 2021–2022 flu season north of the equator will be worse. Why? We are far less likely to be wearing masks, social distancing or keeping our kids home from school this year. Couple that with low vaccination rates for flu this season and a potential flu vaccine strain mismatch, and the likelihood of co-infection rises.
For the week ending December 25, 2021, the U.S. Centers for Disease Control and Prevention reported that 6.2 percent of people tested for flu were positive, and that and 1,825 people were admitted to U.S. hospitals with flu that week. So, what’s more important to know and talk about is that in upcoming weeks, we will see a whole lot of sick people with COVID-19 as well as flu, both single infections of one or the other, but few co-infections, as the math would have it.
Those of us on the front lines hope to see media and influencers focus on matters that are proportionally more relevant to the masses, rather than sensational anecdotes. There are plenty of places on the internet with reliable, credible information, not to mention your own physician and scientists who appear in media. With regards to flu and COVID-19, both are serious illnesses by themselves. More importantly though, they both have safe and effective vaccines to prevent them. There are common mitigation measures that work against both that every reasonable person in the world should know by now and should use. Let us keep the focus on those.