Throughout the summer, Texas’ coronavirus outbreak became grimmer by the day and by almost every metric: case counts, hospitalizations, deaths. But in the past week or so, Abbott and some of the state’s public health officials began to see hope in the daily case counts as they appeared to stabilize.
A growing body of evidence points to widespread mask-wearing as an effective strategy for containing the virus, and one North Texas researcher’s statistical analysis published this week argued that local mask orders in the region reduced viral transmission enough to avoid a lockdown. The governor, who has faced blistering criticism for his handling of the pandemic from members of his own political party, immediately seized upon those findings in defense of his statewide order.
“A community lock down is not needed as long as masks & other distancing strategies are used,” Abbott wrote Monday on Twitter, citing the analysis by Rajesh Nandy, a professor of biostatistics and epidemiology at the University of North Texas Health Science Center.
But public health experts warn that more restrictive lockdowns may still be appropriate in the state’s hardest-hit regions, as the disease continues to infect about 10 times as many people each day compared with two months ago, ravaging some parts of the state more severely than others.
State data now appears to show new daily infections leveling off, albeit at nearly record highs. There were around 9,100 daily new cases of the virus on average over the past week. The state recorded its largest number of daily new cases July 15, at 10,791. On Thursday, that number was 9,507.
“The downside is even though we are approaching another plateau, we are at a much higher level than in May,” Nandy said.
The average percentage of coronavirus tests coming back positive has also fallen over the past week.
Taken together, epidemiologists say those trends may indicate that Texas is reaching a plateau of new cases, where the number of cumulative infections climbs steadily, rather than exponentially. That would hardly represent a victory over the pandemic, but it would help keep hospitals from being overrun with sick patients.
Public health experts say more time is needed to see if daily case numbers hold steady or, ideally, decline — which would also lead to fewer hospitalizations and deaths.
While there is widespread consensus that more people wearing face coverings in public will slow viral spread, researchers disagree over how much credit to assign to the statewide mask order.
“We will probably never know for sure whether the mask mandate is affecting what looks to be at least a leveling off of cases,” said Catherine Troisi, an infectious disease epidemiologist at UTHealth School of Public Health in Houston.
As of July 23, there are 361,125 cases in 250 counties. The average number of cases reported over the past seven days shows how the situation has changed over time by de-emphasizing daily swings. The number of new cases reported drops on weekends, when labs are less likely to report new data to the state.
“It is certainly possible the mask mandate is decreasing spread,” she said. “I hope that’s true, but it’s hard to prove.”
Disease modelers estimate a figure called the reproduction number, which essentially represents how many people, on average, a person infected with the coronavirus will pass it on to. A reproduction number above 1 signals rapid growth, a value of 1 indicates stable growth, and less than 1 means an area is experiencing a decrease in new cases over time and has slowed the rate of transmission.
In the state’s largest urban areas, including Houston and Dallas, researchers are more confident that the rate of transmission has slowed such that the regions’ reproduction numbers are now at or are slightly below 1.