Superspreading events have distinguished the COVID-19 pandemic from the early outbreak of the disease. Now, research from Harvard University, Tulane University, MIT and Massachusetts General Hospital finds that a critical factor in these and other transmission events is the propensity of certain individuals to exhale large numbers of small respiratory droplets. The researchers found that age, obesity and COVID-19 infection all correlate with a propensity to breathe out more respiratory droplets.
Understanding the source and variance of respiratory droplet generation may lead to effective approaches to reducing COVID-19 infection and transmission.
Masks help protect the people wearing them from getting or spreading SARS-CoV-2, the virus that causes COVID-19, but now researchers from the National Institutes of Health have added evidence for yet another potential benefit for wearers: The humidity created inside the mask may help combat respiratory diseases such as COVID-19.
The study, led by researchers in the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), found that face masks substantially increase the humidity in the air that the mask-wearer breathes in. This higher level of humidity in inhaled air, the researchers suggest, could help explain why wearing masks has been linked to lower disease severity in people infected with SARS-CoV-2, because hydration of the respiratory tract is known to benefit the immune system. The study published in the Biophysical Journal.
“We found that face masks strongly increase the humidity in inhaled air and propose that the resulting hydration of the respiratory tract could be responsible for the documented finding that links lower COVID-19 disease severity to wearing a mask,” said the study’s lead author, Adriaan Bax, Ph.D., NIH Distinguished Investigator. “High levels of humidity have been shown to mitigate severity of the flu, and it may be applicable to severity of COVID-19 through a similar mechanism.”
A novel new study suggests that the behavior public officials are now mandating or recommending unequivocally to slow the spread of surging COVID-19–wearing a face covering–should come with a caveat. If not accompanied by proper public education, the practice could lead to more infections.
The finding is part of an unique study, published in JMIR Public Health and Surveillance, that was conducted by a team of health economists and public health faculty at the University of Vermont’s Larner College of Medicine in partnership with public health officials for the state of Vermont.
The study combines survey data gathered from adults living in northwestern Vermont with test results that showed whether a subset of them had contracted COVID-19, a dual research approach that few COVID studies have employed. By correlating the two data sets, researchers were able to determine what behaviors and circumstances increased respondents’ risk of becoming sick.
In the early days of the pandemic, amidst all the uncertainty, one thing was for sure: N95 masks – the personal protective respiratory devices that filter out viruses, bacteria, and wildfire smoke – were in short supply. So when materials scientists Jeff Urban and Peter Hosemann heard that a local HMO needed advice on N95 alternatives, they immediately knew what to do: Make a better mask.
Hosemann got on the phone, and discovered that the HMO’s doctors and supply managers wanted to know what makes an effective antiviral mask, and how they could verify whether the masks they found were actually any good. “It was helpful to learn what their needs were, and how we could fill in and help support their mission,” said Hosemann, who holds titles of faculty scientist in the Materials Sciences Division at Lawrence Berkeley National Laboratory (Berkeley Lab) and Ernest S. Kuh Chair in Engineering at UC Berkeley.