This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

ST. CHARLES COUNTY, Mo. – We’re learning of more people with COVID-19 who are being told they’re testing negative even though they have the virus. The latest warning comes from a St. Charles County woman who wouldn’t have known without getting a second test.

The 48-year-old woman doesn’t want to be identified. She shared her test results showing her false negative. She’s concerned because she stood in line with about 60 other people.

She fears that if her test was wrong – what about the others?

It’s the second time this week we’ve heard warnings about making sure you get a thorough COVID-19 test.

On Monday, the head of Monroe County, Illinois Health Department said he was learning of false negatives from people taking their own tests.

“It has to be a deep nasal swab for it to be an accurate test,” said John Wagner, Monore County Health Administrator. “The last thing we want is positives going around thinking they’re negative. That would be a sure way to spread this quickly.”

The records of the 48-year-old St. Charles County woman revealed she took a COVID-19 test on Sunday, June 28. It was a rapid test that she said showed results in about 30 minutes. The result showed she was negative for the coronavirus.

She said she also asked for an additional lab test that required a deeper nasal swab. Those results, which she also shared with Fox 2, came back Wednesday as positive.

She doesn’t want to be identified because of the extreme emotion around this issue but shared her records with us.

“Don’t be fooled by a false sense of security if you think you’re negative after a rapid test,” she said. “You could be spreading the coronavirus without knowing.”

Dr. Phillip Zinser, director of infection Control at DePaul Health Center, said he’s seen a few false negatives.

“There are many tests that are available. The quality of the tests is improving,” he said. “They are definitely better than they were a couple of months ago.”

“Good collection of the sample is key to getting a good result and that does require that the swab go all the way to the back of the nasopharynx and that they scrub the cells around there and get a good sample.”

The woman who called Fox 2 said both of her tests were taken at urgent care centers. We spoke with a representative of the St. Charles urgent care center where she got her false negative. He connected me with a human resources specialist who promised to look into it. Another representative responded saying the clinic stopped using rapid tests this week.