Tarrant County’s mask mandate helped stabilize growth of new COVID cases, expert says
It’s been about three weeks since Tarrant County required face masks be worn in businesses, and a new report found that the mandate helped stabilize the surge in coronavirus cases locally.
The transmission rate of the novel coronavirus, growth of new COVID-19 hospitalizations and ER visits for suspected COVID-19 patients have leveled off and begun to slightly decline in Tarrant County, according to an analysis by Dr. Rajesh Nandy, an associate professor of biostatistics and epidemiology in the University of North Texas Health Science Center’s School of Public Health.
“We cannot really say that we have seen a complete reversal, but we certainly have seen a stabilization,” since the mask mandate went into effect June 26, Nandy said.
Nandy has been studying the Dallas-Fort Worth Metroplex’s data on hospitalizations, cases and mobility over the course of the pandemic, and while other factors like decreased mobility also likely played a role, Tarrant County’s mask mandate “certainly contributed some.”
And a week after Tarrant County’s local mask order went into effect, Gov. Greg Abbott mandated face coverings be worn in most public places statewide.
The R0, pronounced “R-naught,” is used to estimate the number of new infections transmitted by a single case. If the the R0 is below one, it indicates the virus’ spread is on the decline. In late June, it was as high as 1.35 for Tarrant County, Nandy said. In recent days, the R0 in Tarrant County has hovered just above one.
And a model from the UT Southwestern Medical Center analyzing data through July 16 also found that since Tarrant County’s mask mandate, the virus’ contagiousness has been on the decline from highs in mid-June.
A recent study worked on by researchers from Texas A&M University and UT Austin found that wearing a face mask is one of the most effective ways to prevent the transmission of COVID-19.
Nandy also analyzed local data from the counties of Dallas, Collin and Denton. He found a similar stabilization in levels of transmission, ER visits and hospitalizations across the counties — except in Collin, which is exhibiting the least change and a projected growth in hospitalizations.
Throughout July, the number of emergency rooms visits across Tarrant County for suspected COVID-19 patients has also been on the decline. After reaching a seven-day average of nearly 6.5% in early July, the percentage of emergency department visits from people experiencing COVID-19-like illnesses has trended downward and was at a seven-day average of 4.78% on July 18.
However, hospitalizations have continued to grow — although at a slower pace. Hospitalizations hit an all-time high on July 16, with 708 COVID-19 patients hospitalized in Tarrant County. Just over 70% of the county’s intensive care unit beds — which are usually reserved for the most severe patients — are occupied, Nandy said.
Last week, hospitalizations of COVID-19 patients in Tarrant County increased 4% compared to the previous week, according to the UT Southwestern model. That was the smallest week-over-week growth Tarrant County has seen in the past month, with a 28% and 43% increase in previous weeks.
While the growth of new hospitalizations of COVID-19 patients has slowed in recent weeks, Nandy stressed that hospitals are holding the line in terms of capacity — and staff available to handle a surge in cases.
“Because we are at such a high level right now, even a mini surge might stress the system,” Nandy said in terms of hospital capacity. “Our system can handle where we are right now, even though it’s not the best place to be. But if it starts picking up, that would be a challenge.”
UT Southwestern’s model predicts that by July 30, Tarrant County’s total COVID-19 hospitalizations will be between 600 to 950 cases and roughly 640 new infections per day.
Public health experts attributed the surge in cases throughout June, in part, to people gathering to celebrate the Memorial Day weekend and increased activity as more people venture out. Experts had cautioned residents ahead of the Fourth of July weekend, for fear large gatherings could add more cases.
Based on Google’s community mobility reports, travel to stores, restaurants and recreation locations in Tarrant County was at about 39% below pre-pandemic levels on July 4, compared to about 26% below pre-pandemic levels on Memorial Day. Despite the spike on the Fourth of July, retail mobility has decreased overall since late June, and was at 12% below pre-pandemic levels as of July 14.
Last week, Abbott reiterated that a shutdown — even locally for the hardest-hit regions — was not on the horizon, if Texans abide by his mask mandate.
A document prepared for the White House Coronavirus Task Force and first reported on by the Center for Public Integrity last week, put both Texas and the Dallas-Fort Worth area in the “red zone” for reporting new cases above 100 per 100,000 residents and a positivity rate of over 10%. It recommended additional restrictions to curb the surge in coronavirus cases, like closing gyms and reducing indoor dining capacity to 25%.
Nandy said reinstating a stay-at-home order shouldn’t be ruled out in the event of another surge. However, currently he said it isn’t necessary since the mask mandate appears to be contributing to a leveling off of new cases.
“It’s probably better to be a bit careful,” Nandy said. “But I do think that we are not at a position to call for a complete shutdown at this point.”
But for the mask mandate to be effective, people must comply.
“We have to be very vigilant,” Nandy said. “We are in a delicate position.”
This story was originally published July 21, 2020 at 6:00 AM.
