Reprinted with permission from MediaMatters

At President Donald Trump's campaign rally Thursday in Greenville, North Carolina, he made the absurd claim that "85 percent of the people wearing the masks" get infected with the coronavirus, thus presenting the wearing of protective masks as a hazardous act by itself — with the claim carried on Fox News' live coverage of the rally, as well. At the root of his newest false claim, it turns out, are a number of incorrect posts across far-right news sites pushing public health misinformation — along with Fox News host Tucker Carlson.

And on top of that, Trump has further misunderstood the misleading claims those sources have made.

Trump was recently hospitalized after he tested positive for the coronavirus following a largely mask-free "superspreader" event in the White House Rose Garden to announce the nomination of Judge Amy Coney Barrett to the Supreme Court. Trump's diagnosis also came soon after his family and other guests refused to wear masks while in the audience of the first presidential debate, violating the rules of that event.

"And look at all the masks. You know, they keep saying, 'Nobody wears masks. Where are the masks?'" said Trump. "Although then they come out with things today — did you see, the CDC? That 85 percent of the people wearing the masks catch it, OK?"

Not only is Trump echoing a claim that has been bubbling through the fever swamps of right-wing political sites — essentially mutilating what a recent study actually said about masks, as it looked at the impact of people going into public dining places — he has even gotten that backwards.

The claim, which has been circulated in recent days by conservative outlets including The Blaze, The Federalist, and The Gateway Pundit, among others, is that 85 percent of people who got coronavirus were supposedly either "often" or "always" wearing masks — not the other way around. If Trump's claim that 85 percent of people who wear masks will get the virus was true, then clearly the vast numbers of people who do wear them would have taken ill en masse by now.

But even this right-wing media claim is a serious misunderstanding of just one small study conducted in July and published in September by the Centers for Disease Control and Prevention, which did not even focus on the kind of conclusions that these right-wing sites are drawing. The study examined "outpatients from 11 U.S. health care facilities," to determine what risk factors were involved — focusing not on masks, but on the impact of going to public venues such as restaurants, bars, and coffee shops.

The reason for the study was that these are places in which masks "cannot be effectively worn while eating and drinking, whereas shopping and numerous other indoor activities do not preclude mask use." It determined that "adults with positive SARS-CoV-2 test results were approximately twice as likely to have reported dining at a restaurant than were those with negative SARS-CoV-2 test results."

The study found other significant risk factors as well, such as close contact with family members or other people known to be COVID-positive: "Close contact with one or more persons with known COVID-19 was reported by 42 percent of case-patients compared with 14 percent of control-participants (p<0.01), and most (51 percent) close contacts were family members."

The study also acknowledged a number of its own possible limitations, based largely on its self-reporting nature. These included: Potential test subjects who refused to participate might be "systematically different" from those who did agree to participate; the survey sample from 11 medical facilities might not be representative of the United States as a whole; and test subjects knew they were COVID-positive, which might have influenced the answers they gave to the researchers.

By contrast, CNN's online article back in September, when the study first came out, correctly communicated the main points of what the study was about. Meanwhile, the recent wave of right-wing sites that have twisted the study only emerged in the past few days, appearing to have begun this past Monday.

And then it was on Tuesday's edition of Fox News' Tucker Carlson Tonight, when the host declared in his opening monologue that "the latest for you tonight" in scientific knowledge had found that "almost everyone, 85 percent who got the coronavirus in July, was wearing a mask — and they were infected anyway."

Carlson then discussed this "new study" with pandemic denialist and frequent Fox News guest Alex Berenson, who declared: "Well, it hasn't received coverage because the media doesn't want to cover anything — you know, aside from you and a few other people —don't want to cover anything that says that masks might not be, you know, God's gift to all of us."

Following Trump's remarks on Thursday, CNN anchor Jake Tapper asked the White House what Trump was talking about and was in turn referred to this same study. Tapper then brought on CNN chief medical correspondent Dr. Sanjay Gupta to help explain how Trump has misrepresented the study's findings.

"I don't know if he misunderstood, or if he's just lying about it — it's dangerous," said Tapper. "It is not true that the study said, '85 percent of people who wear masks catch the virus.' It's a lie."

"No, it's absolutely a lie," Gupta replied. "That isn't even what the study was trying to determine. As you pointed out, Jake, it was a totally different sort of focus of the study."

Gupta also explained a problem with the self-reporting nature of the study: "About half the country regularly or sometimes wears a mask. We know that from lots of different studies. In this self-reported study, about 8 out of 10 people said that they regularly or sometimes wore a mask. Point is it's self-reported, it's very hard to make any sense of that data."

So in short, right-wing sites and Carlson mangled the results of a study that examined the self-reported habits of people who might have caught the coronavirus from going to venues where masks "cannot be effectively worn," to then suggest that masks are useless to stop the virus. The president of the United States went even further by completely reversing the story to declare that people who do wear masks will get the virus in overwhelming percentages.

And when the president made that statement, the people at his campaign rally cheered — with the claim getting amplified further on TV.