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Here's how effective face mask mandates are, according to SLU study

Researchers looked at the three weeks before face mask mandates were put in place back in July in St. Louis and St. Louis County

ST. LOUIS — A new study from Saint Louis University found face mask mandates work. 

Researchers looked at the three weeks before face mask mandates were put in place back in July in St. Louis and St. Louis County.

They also looked at the 12 weeks after the mandate was put in place.

COVID-19 cases in counties in surrounding areas — Franklin, Jefferson and St. Charles counties — which don't have mask mandates did not drop.  

The study found that case growth in the city and county was about 40% slower than in those counties without a mask mandate.

The data was put together using percent changes in COVID-19 cases by day and location, with 530 observations from June 12 through Sept. 25.

A total of 44,294 cases were reported throughout this period among a total estimated population of just over 2,000,000 residents, which is approximately one-third of the population within the state, according to the study.

Credit: SLU researchers

“The data shows that in every environment that this has been studied when you put in a mask mandate more than 80% of that specific population is following it. It's going to have a reduction," said Dr. Enbal Shacham, the lead author on the study.

The study also found the mandate narrowed racial disparities in virus spread.

Editor's note: The study has not yet been peer-reviewed.

St. Louis Metropolitan Task Force wants statewide mask mandate

On Nov. 13, Dr. Alex Garza, the head of the task force, called for statewide measures to prevent the spread of COVID-19 including a face mask mandate; a statewide "safer at home" policy and a plan to help health care workers.  

"The statewide mask mandate is needed to save lives across the state," Dr. Garza said.

Hospitalizations related to COVID-19 continue to reach record levels in the St. Louis area. 

Dr. Garza said patients from other parts of the state - where mandates are not currently in place - are coming to St. Louis area hospitals for treatment.

Missouri is one of the states without a face mask mandate - 36 states have put a mandate in place. 

No mask mandates in Franklin County, Jefferson County or St. Charles County

While there's no mask mandate in Jefferson County, health officials are urging residents to act now as COVID-19 cases keep surging in the area. 

The county remains in the highest alert status of 'red' with the seven-day rolling average of COVID-19 cases per day/per 100,000 residents at 95.05, which makes it the highest seven-day rolling average recorded in Jefferson County since the start of the pandemic, according to the health department.

St. Charles County Executive Steve Ehlmann issued a warning to residents, urging them to change their behaviors immediately to stop COVID-19 spread.

“Our county is facing a severe rise in positive cases and hospitalizations, as well as an increase in deaths,” Ehlmann said. “I am calling on each county resident to do what is necessary to help us get this virus under control.” 

St. Louis County enacts stricter face mask requirements 

On Nov. 17, St. Louis County put three new public health orders in place to control the spread of the virus.

  1. Safer at Home order
  2. Revised quarantine and isolation procedures order
  3. Strengthened face covering order

Anyone 6 years and older must now wear a face mask when they leave the house, including when they visit someone else's house. An exception can be made while eating or drinking as long as social distancing is being practiced, according to the order.

Masks must be worn at gyms while working out and at sports settings, except while actively playing.

Page said while 3-5-year-olds aren’t required to wear masks, it is strongly encouraged.

Exceptions to the mask rule continue to include those with medical conditions that prevent them from wearing a mask.

CDC on face masks

Earlier this month, the CDC said wearing a face mask not only protects others from the spread of the coronavirus, but it protects the wearer too.

"Adopting universal masking policies can help avert future lockdowns, especially if combined with other non-pharmaceutical interventions such as social distancing, hand hygiene, and adequate ventilation," the CDC said in its document that details scientific evidence.

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