Masks Play Key Role in Slowing Spread of COVID-19

Woman wearing a mask

Because of the highly contagious Delta variant, the Centers for Disease Control and Prevention recommends everyone, even vaccinated people, wear a mask in public indoor spaces in areas of high transmission.

Masks are required to enter MU Health Care facilities, and some businesses and schools also require masks for entry. Here are the latest guidelines on masks:

Who should wear a mask?

Christelle Ilboudo, MD
Christelle Ilboudo, MD

The CDC says face masks should be worn by everyone 2 years and older when in public indoor settings in areas with high or substantial community transmission of COVID-19. That applies even to fully vaccinated people. In general, masks are not needed outdoors but should be considered in crowded settings such as sporting events and concerts in areas with high numbers of COVID-19 cases.

“Masks work,” said Christelle Ilboudo, MD, pediatric infectious disease expert and MU Health Care’s medical director of infection control and prevention. “The more we can limit exposure in our activity, the better protected we will be overall.”

In studies of outbreaks, mask-wearing has been shown to reduce community transmission by as much as 70-80%. One population-based study in Kansas found that over a nine-month period in 2020, counties with mask mandates saw a 60% decrease in COVID-19 cases and hospitalizations and a 65% reduction in deaths compared to counties without mask mandates.

Are masks effective?

COVID-19 is spread through water droplets, and although masks aren’t 100% effective as a barrier, they can reduce the distance droplets travel. If you imagine how far droplets from a sneeze travel if not covered, it’s easy to see how a mask limits their spread.

“Masks, distancing, hand-washing and staying home when you’re sick all work in conjunction to stop outbreaks before they happen,” Ilboudo said. “Masks are the easiest thing we do as individuals, which is why we keep emphasizing masking. It is easier for me to wear a mask than to replace the entire ventilation system in a school building.”

What type should I wear?

The CDC recommends masks with at least two layers of breathable, washable fabric and an adjustable nose wire. Disposable masks, made of non-woven material with a nose wire, also offer protection. Multilayer neck gaiters can be used, and single-layer gaiters can be folded to offer better protection.

Children should wear masks made for their smaller faces. Those will fit better and provide better protection.

The CDC does not recommend masks made of material such as vinyl, which restricts breathing, masks that have ventilation valves or ports, or N95 masks prioritized for use by health care workers. The use of face shields without a mask is not effective protection against exposure.

How do I wear a mask properly?

The mask should completely cover your nose and mouth, fit snugly under your chin and against the sides of your face without gaps, and it should have a nose wire to prevent air escaping the top of the mask. It should have ear loops, or it should tie behind your head, keeping it securely in place so you don’t need to constantly readjust it with your hands.

How do I sanitize a mask at home?

If you use a cloth mask, washing it in the washing machine after you wear it is enough to sanitize it. Just be sure to choose materials that can be washed and dried without shrinking or being damaged. As the name suggests, disposable masks cannot be re-used. Wash your hands after handling a dirty mask.

The key takeaway: If you’re going out in public, wearing a mask can go a long way in reducing the spread of COVID-19.

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