LOCAL

COVID-19 testing falls in Texas, but spread continues

Philip Jankowski
Tonia McQueen takes a sample from construction worker Victor Sanchez for a COVID-19 test at a free testing site for construction workers at Sacred Heart Catholic Church in Austin on June 20. Testing throughout the state has declined in recent weeks as the rate of positive cases has climbed.

The amount of coronavirus testing in Texas has decreased substantially in recent weeks, just as the rate of positive cases has climbed, state data show, raising concerns about the accuracy of recent trends that show a declining number of new cases.

As of Monday, the weekly average of molecular coronavirus tests conducted statewide had fallen to its lowest level since June 21. Meanwhile, the rate of tests returning positive results more than doubled over that same period.

It is a troubling trend, disease experts say — one that shows not nearly enough testing is happening in Texas and that the actual number of coronavirus cases is likely far higher than what the state is reporting.

CORONAVIRUS IN TEXAS: What we know, latest updates

“It is really frustrating from an epidemiological stance,” said Angela Clendenin, an epidemiologist at the Texas A&M University School of Public Health. “Testing isn’t just about confirmatory testing. Testing during a pandemic, particularly with a novel disease, needs to be very robust and very widespread so we can determine the burden of what we are dealing with.”

The World Health Organization has said that a 3% positivity rate is indicative that adequate testing is happening.

On Monday, 21% of Texas coronavirus tests returned positive results. Meanwhile, testing had declined nearly 49% since its peak on July 22.

The testing peak was just one week after the amount of new cases had peaked with several days of more than 10,000 new confirmed cases reported statewide. That number was down to 8,913 on Tuesday. In total, 500,620 cases of the coronavirus have been confirmed in Texas and 8,710 people have died from the virus, according to the Texas Department of State Health Services.

The decline in testing also shows continued flaws in the state’s data collection efforts. County-level counts of cumulative tests from the state health department show a contradictory trend — that in most counties testing is actually increasing, according to an American-Statesman analysis.

The culprit behind the disconnect is the vast number of tests that the state health department is counting as “pending assignment,” where more than a half million tests remain unassigned to any specific county.

To make matters more confusing, it is unclear what date the state health department assigns those pending tests when they are assigned to a county, leading to data illustrating a sharp increase in cases on the local level while it is far more likely that those numbers have fallen.

How it works is that even while the county-level data show local increases, the number of tests unassigned to a county has dropped sharply from more than 1 million last week to Monday’s count of 578,106 tests pending assignment.

The Texas Department of State Health Services did not respond Tuesday to an inquiry seeking elaboration on how it doles out tests that it considers “pending assignment.” However, a department spokeswoman indicated Monday that the recent decline in testing appears to remain a mystery to them.

“We are looking into why the number of lab tests reported to DSHS has been trending lower over the past few days,” DSHS spokeswoman Lyndsey Rosales said in an email. “The number of test results received affects the positivity rate. We are closely analyzing our data to uncover any anomalies. DSHS is also reaching out to the larger clinical labs and statewide health care associations to find out if they are seeing a similar trend.”

On Monday, Gov. Greg Abbott told KAUZ-TV in Wichita Falls that testing conducted in private labs was leading to a longer lag time for test results.

“We're trying to get away from using those commercial labs,” Abbott said. “I will tell you this, however, and that is, you're about to see the test turnaround not be several days, but be less than an hour, because beginning maybe as early as next week, we will have quick turnaround — as in 15-minute turnaround tests used at nursing homes.”

Abbott did not say who would be conducting those tests if not commercial labs. As of Monday, commercial labs had performed 97% of coronavirus tests in Texas, according to the state health department.

Clendenin, the Texas A&M epidemiologist, said lag times have increased at some labs due to a lack of medical technologists available to run these tests.

Meanwhile, Austin Public Health’s interim director Dr. Mark Escott said Tuesday that recent declines in the local health department’s testing are not from any lack of supply.

“This is not because tests aren’t available, this is because less people are signing up for testing,” Escott said during a meeting of the Travis County Commissioners Court.

Abbott’s comments on Monday reference rapid antigen tests. Those have a higher tendency to return false negatives, but Clendenin said they might be the key to rapidly increasing testing in Texas while eliminating the lag times in test results that have plagued testing from the start.

Currently, the state health department does not count positive results from rapid antigen counts as confirmed cases, labeling them instead as probable.

“We may need to sacrifice that gold standard a bit for antigen tests and begin accepting those as a little more confirmatory than we currently do,” Clendenin said.