[guest post by Dana]
State assembly member Autumn Burke (D-Inglewood) reported that she was told that she had “mask to mask” exposure to Covid-19, and days later, tested positive for the coronavirus:
Burke had “mask to mask” exposure to the virus on June 26, she said — the same day that an Assembly employee was last in the Capitol before testing positive. That employee wore a face covering at all times, according to an Assembly Rules Committee email.
It goes without saying that we wish Ms. Burke and her daughter well, and prayerfully they remain symptom-free.
With that, I haven’t seen any report specifically citing mask-to-mask exposure leading to infection before this one. If you have seen a report making a similar claim, please link to it in the comments.
Anyway, as of Monday morning, the California Assembly is now on an indefinite hiatus:
The Assembly is suspending its session until further notice following five confirmed COVID-19 cases among lawmakers and employees.
John Casey, a spokesman to Assembly Speaker Anthony Rendon, said the Assembly is “closed until further notice,” meaning it will not return for previously scheduled legislative hearings on Monday.
Note:
The Assembly recorded its first COVID-19 case on June 22, when an employee tested positive after reporting to work in the Capitol the week prior…
Meanwhile, there has been a post making the rounds on social media that presents an alleged “contagion graphic” indicating to what degree mask-wearing interferes with the transmission of coronavirus. Here is the unsourced claim:
Kasier Family Foundation recently looked into the claims being asserted. Because there was no source information to refer to, they contacted the CDC (Center for Disease Control) to see if they could substantiate the claims with actual research. No such luck:
“We have not seen or compiled data that looks at probabilities like the ones represented in the visual you sent,” Jason McDonald, a member of CDC’s media team, wrote in an email. “Data are limited on the effectiveness of cloth face coverings in this respect and come primarily from laboratory studies.”
McDonald added that studies are needed to measure how much face coverings reduce transmission of COVID-19, especially from those who have the disease but are asymptomatic or pre-symptomatic.
Other public health experts we consulted agreed: They were not aware of any science that confirmed the numbers in the image.
“The data presented is bonkers and does not reflect actual human transmissions that occurred in real life with real people,” Peter Chin-Hong, a professor of medicine at the University of California-San Francisco, wrote in an email. It also does not reflect anything simulated in a lab, he added.
Andrew Lover, an assistant professor of epidemiology at the University of Massachusetts Amherst, agreed. He had seen a similar graphic on Facebook before we interviewed him and done some fact-checking on his own.
“We simply don’t have data to say this,” he wrote in an email. “It would require transmission models in animals or very detailed movement tracking with documented mask use (in large populations).”
…
“We get the most protection if both parties wear masks,” Linsey Marr, a professor of civil and environmental engineering at Virginia Tech who studies viral air droplet transmission, wrote in an email. She was speaking about transmission of COVID-19 as well as other respiratory illnesses.
Chin-Hong went even further. “Bottom line,” he wrote in his email, “everyone should wear a mask and stop debating who might have [the virus] and who doesn’t.”
However incorrect the percentages are in the graphic, mask wearing is favored as a preventative measure to limit the transmission of droplets and aerosols:
“The main reason that the masks do better in the outward direction is that the droplets/aerosols released from the wearer’s nose and mouth haven’t had a chance to undergo evaporation and shrinkage before they hit the mask,” wrote Marr. “It’s easier for the fabric to block the droplets/aerosols when they’re larger rather than after they have had a chance to shrink while they’re traveling through the air.”
So, the image is also right when it implies there is less risk of transmission of the disease if a COVID-positive person wears a mask.
“In terms of public health messaging, it’s giving the right message. It just might be overly exact in terms of the relative risk,” said Lover. “As a rule of thumb, the more people wearing masks, the better it is for population health.”
Ulitmately, Kasier Family Foundation drew this conclusion about their findings:
Experts agreed the image does convey an idea that is right: Wearing a mask is likely to interfere with the spread of COVID-19.
But, although this message has a hint of accuracy, the image leaves out important details and context, namely the source for the contagion probabilities it seeks to illustrate. Experts said evidence for the specific probabilities doesn’t exist.
–Dana
