With the omicron variant of COVID-19 sweeping through North Texas and around the country, many people are relying on rapid tests to determine if they have the virus, especially over the holidays when people wanted ensure they did not expose friends and family to COVID-19.

However, the accuracy of rapid tests has led to some concerns and unfortunate situations recently.

When Sarah Sedaghatzadeh began to feel slightly ill near the end of December, she underwent a rapid COVID-19 test that showed she was negative. Sedaghatzadeh trusted the results and spent time with friends and family members.

Two days later, Sedaghatzadeh underwent a PCR test, and the results showed that she was positive, meaning her previous result had been a false negative.

Sedaghatzadeh’s entire family, including her mother, pregnant sister, brother-in-law, and her boyfriend, also ended up testing positive for COVID-19.

“It’s the worst feeling in the world I’m telling you right now,” she told The Dallas Morning News. “I spread it to everybody in my family. And, I mean, it sucks.”

Sedaghatzadeh and her entire family have now successfully recovered from COVID-19, but it was a learning experience about the dependability of rapid tests.

“Now I’m just like, masks everywhere even though I’m vaccinated,” she said. “I just want to be more precautious now. And if I’m feeling slightly sick, now I’m like, don’t risk it. Even if it says negative, don’t risk it. I think that’s my biggest learning lesson in all this.”

Sedaghatzadeh’s experience highlights the shortcomings of rapid COVID-19 tests. Last month, the FDA, in conjunction with the National Institutes of Health, released an announcement cautioning against relying solely on rapid antigen tests, saying they “do detect the omicron variant but may have reduced sensitivity,” especially in the early stages of infection.

Dr. Hafiza Khan, a Plano cardiologist, spoke with NBC 5 about the dependability of rapid antigen tests.

“Well, no test is perfect,” Dr. Khan said, “the home antigen tests take a while to turn positive, so after experiencing symptoms, the home antigen test may not turn positive for a day or two. The amount of virus has to build up before the home antigen test will turn positive. The other thing to remember is that the antigen tests are not as sensitive as the PCR tests, although they are certainly very convenient.”

The more convenient and affordable rapid antigen tests work by detecting proteins that the coronavirus carries and give you the results quickly. PCR tests are more sensitive because they detect the viral RNA, but it can sometimes take a few days to get the results.

Hafsa Irfan also had a similar situation in mid-December. After learning that she was exposed to COVID-19, Irfan was able to take a rapid test and two PCR tests. The results for the rapid test and first PCR test came back negative. However, the second PCR test, which she took only 20 minutes after the first, revealed she was positive.

“At first, I was really confused because my sore throat kind of went away in a day. So I was like, ‘oh, there’s no way I have it,’ like I don’t feel anything,” Irfan said. “But you can definitely still carry it.”

Dr. Philip Huang, Director and Health Authority for the Dallas County Health and Human Services Department, suggests taking precautions even if a rapid test shows your negative.

“If you had a negative because of the false negatives, then it just means the test didn’t come back positive,” Dr. Huangtold The DMN, “it doesn’t mean that you might not come back positive the next day or later when it’s repeated. So you still need to take precautions.”

Dr. Huang explained that the increase in false negatives is due to a rise in testing around the holidays and the rapid spread of the omicron variant. Dr. Huang recommends that if you are experiencing symptoms, taking the more reliable PCR test instead of the rapid test, if possible, would be the best option.

“It needs to be used appropriately and interpreted appropriately,” Dr. Huang said. “It’s one tool that we have, it’s not perfect, and that’s where we hope it doesn’t give them a false sense of security.”