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Fact check: CDC report doesn't show mask-wearers are more likely to contract COVID-19

The claim: CDC report shows mask-wearers are more likely to contract COVID-19.

It's been over six months since the Centers for Disease Control and Prevention recommended that Americans wear face masks in public spaces to combat the spread of COVID-19.

But some internet users continue to question the effectiveness of covering their faces.

Posts on Facebook, for example, use a chart from the CDC's Morbidity and Mortality Weekly Report to state that masks actually raise the risk of contracting COVID-19. One data point — that 70.6% of patients who tested positive for COVID-19 had self-reported that they "always" wore masks — is highlighted.

"This evidence suggests that masks actually help to infect the people who wear them," a post reads.

Another post claims that the data proves that "people who wear masks, are actually 'collecting' the virus in their masks. The airborne particles are being absorbed into the Masks and staying on our faces rather than dissipating."

The users behind the posts — both of which were shared thousands of times — did not respond to a request from USA TODAY for comment.

More: Fact check: What's true and what's false about coronavirus?

Report shows that mask-wearing helps stave off the virus and slow the spread

The chart in the posts is legitimate, and comes from the CDC's Morbidity and Mortality Weekly Report on Sept. 11. But the chart and report both support a very different conclusion from the posts on Facebook.

In fact, in a tweet on Oct. 14, the CDC said the study's results were being misinterpreted.

"A recent (CDC Morbidity and Mortality Weekly Report) looking at exposures among people w/ and w/o #COVID19 also assessed rates of mask use. However, the interpretation that more mask-wearers are getting infected compared to non-mask wearers is incorrect."

Taking the mask off to eat in a public setting had a lot to do with contraction of coronavirus, the study found.

"People w/ and w/o #COVID19 had high levels of mask use in public. Even for those who always wear a mask, there are activities where masks can’t be worn, like eating or drinking. People w/ COVID-19 were more likely to have eaten in a restaurant," the CDC further tweeted.

The report analyzed the characteristics of 314 symptomatic adults who received positive and negative SARS-CoV-2 test results between July 1-29.

Of those 314 patients, 154 tested positive, referred to in the chart as "case patients." Another 160 tested negative, referred to in the chart as "control patients."

It's true, as the post claims, that 70.6% of the "case patients" self-reported always wearing masks. But an even higher percentage of the "control patients" who did not contract the virus self-reported always wearing masks, at 74.2%, which suggests that their mask-wearing may have helped stave off the virus.

Another reason both percentages are so high is because the majority of study participants — 226 of 314 patients, or 72% — reported they "always" wore masks. Their widespread use makes it difficult to detect their effect.

On the flip side, just 11 patients in the study reported that they "never" wore masks. So the percentage of individuals who tested positive and never wore masks was guaranteed to be low — it was 3.9%, compared 3.1% of individuals who tested negative.

In this file photo taken on April 24, 2020, shows the Centers for Disease Control (CDC) headquarters in Atlanta, Georgia.
In this file photo taken on April 24, 2020, shows the Centers for Disease Control (CDC) headquarters in Atlanta, Georgia.

Close contacts, public activities

The report found that close contact with individuals with known COVID-19 was a major risk factor. Over 40% of "case patients" who tested positive had close contact with an infected individual, compared to just 14% of "control patients."

Given that statistic, the report recommends that anyone who is in close contact with infected persons take "additional prevention measures" to reduce transmission, such as "wearing gloves, and wearing masks."

The report also found that participating in public activities that preclude mask use — like eating or drinking — is a risk factor, further supporting the importance of masks.

"Exposures and activities where mask use and social distancing are difficult to maintain, including going to locations that offer on-site eating and drinking, might be important risk factors for SARS-CoV-2 infection," it reads.

Fact check: White House reporters wear masks on grounds; post claiming otherwise is false

Do masks collect particles or worsen the risk of contracting COVID?

There is nothing in the report to back the claim that masks collect virus particles or make patients more likely to contract COVID-19.

Wesley Self, one of the study’s lead authors and a professor at Vanderbilt University School of Medicine, wrote in an email to Health Feedback that “We are not aware of any of our data showing that wearing a mask increases the risk for COVID-19.”

Ben Neuman, a virologist at Texas A&M University-Texarkana, evaluated one of the posts and the report for PolitiFact, and concluded there was "nothing in this (report) that indicates that mask wearing is associated with more coronavirus."

"Honestly, I don’t even know how that could be possible," he said.

In reality, numerous studies have found that mask-wearing slows the spread of the coronavirus.

That's because COVID-19 mostly spreads through respiratory droplets. Masks provide a simple barrier to prevent respiratory droplets from traveling into the air and onto others when an infected individual coughs, sneezes or talks, per the CDC.

Masks are most effective if they are widely used in public settings.

Our rating: False

Based on our research, the claim that a study from the Centers for Disease Control and Prevention shows that mask-wearers are more likely to contract COVID-19 is FALSE. The report actually supports the efficacy of masks in slowing the spread of coronavirus. Numerous other studies also confirm that conclusion.

Our fact-check sources:

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This article originally appeared on USA TODAY: Fact check: CDC study does not find that masks are ineffective