Visitors wearing face masks leave the Alamo, Wednesday, March 3, 2021, in San Antonio. Gov. Greg Abbott says Texas is lifting a mask mandate and lifting business capacity limits next week. (AP Photo/Eric Gay)

Study finds mask mandates, dining out influence virus spread

Study finds mask mandates, dining out influence virus spread

NEW YORK — A new national study adds strong evidence that mask mandates can slow the spread of the coronavirus, and that allowing dining at restaurants can increase cases and deaths.

The Centers for Disease Control and Prevention released the study Friday.

“All of this is very consistent,” CDC Director Dr. Rochelle Walensky said during a White House briefing on Friday. “You have decreases in cases and deaths when you wear masks, and you have increases in cases and deaths when you have in-person restaurant dining.”

The study was released just as some states are rescinding mask mandates and restaurant limits. Earlier this week, Texas became the biggest state to lift its mask rule, joining a movement by many governors to loosen COVID-19 restrictions despite pleas from health officials.

“It’s a solid piece of work that makes the case quite strongly that in-person dining is one of the more important things that needs to be handled if you’re going to control the pandemic,” said William Hanage, a Harvard University expert on disease dynamics who was not involved in the study.

The new research builds on smaller CDC studies, including one that found that people in 10 states who became infected in July were more likely to have dined at a restaurant and another that found mask mandates in 10 states were associated with reductions in hospitalizations.

The CDC researchers looked at U.S. counties placed under state-issued mask mandates and at counties that allowed restaurant dining — both indoors and at tables outside. The study looked at data from March through December of last year.

The scientists found that mask mandates were associated with reduced coronavirus transmission, and that improvements in new cases and deaths increased as time went on.

The reductions in growth rates varied from half a percentage point to nearly 2 percentage points. That may sound small, but the large number of people involved means the impact grows with time, experts said.

“Each day that growth rate is going down, the cumulative effect — in terms of cases and deaths — adds up to be quite substantial,” said Gery Guy Jr., a CDC scientist who was the study’s lead author.

Reopening restaurant dining was not followed by a significant increase in cases and deaths in the first 40 days after restrictions were lifted. But after that, there were increases of about 1 percentage point in the growth rate of cases and — later — 2 to 3 percentage points in the growth rate of deaths.

The delay could be because restaurants didn’t re-open immediately and because many customers may have been hesitant to dine in right after restrictions were lifted, Guy said.

Also, there’s always a lag between when people are infected and when they become ill, and longer to when they end up in the hospital and die. In the case of dining out, a delay in deaths can also be caused by the fact that the diners themselves may not die, but they could get infected and then spread it to others who get sick and die, Hanage said.

“What happens in a restaurant doesn’t stay in a restaurant,” he said.

CDC officials stopped short of saying that on-premises dining needs to stop. But they said if restaurants do open, they should follow as many prevention measures as possible, like promoting outdoor dining, having adequate indoor ventilation, masking employees and calling on customers to wear masks whenever they aren’t eating or drinking.

The study had limitations. For example, the researchers tried to make calculations that accounted for other policies, such as bans on mass gatherings or bar closures, that might influence case and death rates. But the authors acknowledged that they couldn’t account for all possible influences — such as school re-openings.

“It’s always very, very hard to thoroughly nail down the causal relationships,” Hanage said. “But when you take this gathered with all the other stuff we know about the virus, it supports the message” of the value of mask wearing and the peril of restaurant dining, he added.

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Mike Stobbe, The Associated Press

Coronavirus

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

The Business Council of Alberta says the federal budget is nearly silent on Canada’s energy sector. (File photo by The Canadian Press)
Business Council of Alberta mostly disappointed in federal budget

Investments in childcare and early learning commended

.
3-hour paid leave for Albertans to get vaccinated in the works

The UCP government intends to introduce legislation that will ensure working Albertans… Continue reading

Alberta completed 18,412 COVID-19 tests, as reported on Wednesday, for a test positivity rate of 9.5 per cent. (NIAID-RML via AP)
Highest daily count of 2021 so far: Alberta reports 1,699 COVID-19 cases

Variants now make up 59 per cent of Alberta’s active cases

Several cases of COVID-19 were reported among employees of stores at Bower Place Mall. (Photo by LANA MICHELIN/Advocate staff).
COVID-19 cases reported at Bower Place mall stores

AHS said five complaints were investigated since March, and required changes made

Westerner Park’s Exhibition Hall was used as a vaccination clinic on Wednesday. A steady stream of people came to get their COVID-19 shots either by appointment or as walk-ins. Photo by PAUL COWLEY/Advocate staff
No long lineups at walk-in vaccination site in Red Deer

A steady stream of people walked into Westerner Park on Wednesday to… Continue reading

Linda Tomlinson
Gardening: Leave the lawn until the soil is dry

Spring is arriving, Alberta style with warm days, cold days and snow.… Continue reading

Anderson scores twice as Canadiens down Oilers 4-3

Anderson scores twice as Canadiens down Oilers 4-3

New York Liberty guard Kia Nurse (5) shoots next to Indiana Fever's Kamiah Smalls during the first half of a WNBA basketball game Thursday, Sept. 10, 2020, in Bradenton, Fla. Nurse isn't just one of Canada's finest female basketball players, she's becoming a popular voice of the game as well. THE CANADIAN PRESS/AP -Phelan M. Ebenhack
Canadian basketball star Nurse is carving out space in sports broadcasting at just 25

Canadian basketball star Nurse is carving out space in sports broadcasting at just 25

The D.C. Defenders, right, line up against the Seattle Dragons for the opening kickoff of the opening football game of the XFL season, in Washington, Saturday, Feb. 8, 2020. Despite heated social media discussion in Canada, talks between the CFL and XFL haven't addressed what rules could be implemented in a potential partnership. THE CANADIAN PRESS/AP-Stephen Whyno
CFL commissioner Ambrosie says talks with XFL have centred around business, not rules

CFL commissioner Ambrosie says talks with XFL have centred around business, not rules

Former B.C. university rowing coach ‘deeply sorry’ after complaints

Former B.C. university rowing coach ‘deeply sorry’ after complaints

Canada's Brianne Jenner (19) and Russia's Anna Shibanova (70) battle for position in front of Russia goaltender Alexandrova Nadezhda (31) during third period IIHF Ice Hockey Women's World Championship preliminary round action in Plymouth, Mich., on Monday, April 3, 2017. The women's world hockey championship in Nova Scotia has been cancelled a second time because of COVID-19. THE CANADIAN PRESS/Jason Kryk
Women’s world hockey championship in Nova Scotia cancelled again

Women’s world hockey championship in Nova Scotia cancelled again

Canada's Meagan Duhamel and Eric Radford compete in the pairs figure skating free program at the Pyeonchang Winter Olympics Thursday, February 15, 2018 in Gangneung, South Korea. THE CANADIAN PRESS/Paul Chiasson
“Once in a lifetime opportunity” – Radford, James are Canada’s newest pairs team

“Once in a lifetime opportunity” - Radford, James are Canada’s newest pairs team

A school bag and a lunch bag are seen in the schoolyard at Bancroft Elementary School as students go back to school in Montreal on Monday, Aug. 31, 2020. Alberta Education Minister Adriana LaGrange says the organization representing the province's teachers is playing politics with a proposed new kindergarten to Grade 6 curriculum and isn’t sincere about a real bridge-building effort. THE CANADIAN PRESS/Paul Chiasson
Alberta teachers and education minister swap accusations of politicizing curriculum

Alberta teachers and education minister swap accusations of politicizing curriculum

Most Read