CRESTED BUTTE, Colo. (KDVR) — A Crested Butte nurse diagnosed with coronavirus nearly a month ago had a shocking realization during her COVID-19 retest process.

As a health care worker, Lisa Merck decided to err on the side of caution and wait for two negative retest results before returning into the community.

On day 23 of isolation, she’s experiencing a complete 180 in symptoms.

“The last couple of days I’ve been great,” Merck said.

However, Merck recently learned some not-so-great news.

“My second retest came back positive,” she said, adding, “I had kind of a sinking feeling like, ‘Oh my gosh, what now?'”

The positive retest result shocked Merck because results from another test days before were negative.

“March 8, I had my initial COVID-19 test, that was positive. March 23, I had a negative retest. And then on March 30, I had a positive,” Merck said. “The state actually had to call the CDC for guidance because they haven’t really had that case before.”

Colorado Department of Public Health and Environment still recommends the average person with coronavirus should isolate for at least seven days from when symptoms started.

CDPHE says you also should not have a fever for at least three days before ending isolation and your symptoms should have improved. According to CDPHE, health care workers may have to isolate for longer and should do what they are told by the health care facility where they work.

“Are we just walking around and infecting each other?” Merck asked.

Merck no longer has a fever and her symptoms have improved.

“But I’m on day 23 and I’m still shedding, so if I went back to work, that’s dangerous. That’s really, really unsafe and I’m scared for our health care workers,” Merck said.

FOX31 asked the state for a possible explanation for Merck’s mixed retest results. We also asked if CDPHE is considering changing isolation time recommendations with this new information. We have not received a response at this time and will update this story when new information is available.