DALLAS (CBSDFW.COM) – Testing of grocery store employees without Covid-19 symptoms was put on hold Thursday, three days after it was first offered at the American Airlines Center and the Ellis Davis Field House in South Dallas.

A spokeswoman with the U.S. Department of Health and Human Service pointed to the CDC’s guidelines for testing sites that are federally-supported, such as the AAC and the Ellis Davis Field House.

Those guidelines only consider healthcare facility workers and first responders who don’t have any symptoms of the virus.

Dallas County leaders said federal officials are in the process of updating its guidelines for criteria at sites where it provides the testing kits.

Judge Clay Jenkins said because the two federally supported test sites haven’t reached their newly expanded capacity, he wanted to use available test kits for others who are at high risk.

“These grocery store workers are literally being around hundreds of people a day so that is exposing these workers to the possibility of getting sick,” Judge Jenkins said.

Since grocery store employees were allowed to be tested this week, city of Dallas records show the number of visitors at the AAC and the Ellis Davis Field House jumped to more than 400 at each site.

The limit at each site is 500 per day.

On Thursday, the county also began having Parkland Hospital take test kits from the two drive-thru sites to a nursing home to test residents.

On Saturday, the county tested 80 residents at the Duncanville Health and Rehab after two people tested positive for the virus.

Results showed there were 20 people who tested positive.

Judge Jenkins said that’s why he wanted to increase testing at nursing homes.

“We’ll have the flexibility with our mobile units to get to people who are most in need of testing,” he said.

The city of Dallas tweeted late Thursday afternoon that both facilities reached their maximum testing capability.

Experts say more testing is needed in the county and across the state as the economy gradually reopens.

But they also say there are limitations and that not everyone who wants a test can get one.

Dr. John Carlo, a former President of the Dallas County Medical Society, and now CEO of Prism Health North Texas, said the Covid-19 tests are essential in detecting the virus early.

But he said the tests are most accurate when people actually have symptoms.

“If you’re symptomatic, the test is more likely to be positive. Because it’s looking at the number of virus particles in that test.

When somebody does not show signs of symptoms and is asymptomatic, the test isn’t as good.”

He said people must remember, tests are good only on the particular day they’re given. “One of the limitations about determining somebody is infections or not, you may only have that answer today. We don’t know what that would look like tomorrow, the next day, the next day after that. Certainly, we’re not going to test everybody, everyday.”

Long term, Carlo said, in addition to a strong testing program, what’s needed are a vaccine and medicine that can be given to patients to lessen the severity of the virus.

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