KANSAS CITY, Mo. — The demand for COVID-19 testing is still at an all-time high but deciding what type of test to take is the question.

Health leaders say there are some guidelines to follow when choosing to take a PCR or rapid antigen test.

“Both of the tests are very good test,” Dr. Ginny Boos, Director of the Infection Prevention at St. Luke, said. “They just have to be used in the way that they were designed for.”

Boos said the difference between a PCR test and antigen test is their sensitivity to the virus.

A PCR test is very sensitive to COVID meanwhile an antigen test is less sensitive and only picks up the virus at a higher level.

“If you’ve been exposed and maybe you don’t have symptoms, but you know that you’ve had a direct exposure from someone that has had the virus, then a PCR is really the best test to take,” Boos said.

Boos said a PCR test is the way to go if you’ve been exposed and don’t have symptoms, but she said it’s better to take an antigen test over a PCR test if you do have symptoms, but a PCR test would work.

Boos said sometimes people can test positive up to four months using a PCR test because of its sensitivity to the virus that’s why after five to ten days an antigen test is a better option.

She said after having COVID for several days someone could be infected, but not infectious.

“After you’ve tested positive, then you can still transmit some of that virus, it’s just that viral load that is typically referred to isn’t as potent,” Boos said. “So, if you’re wearing a mask then you really aren’t likely to spread the virus to other people in the level that would put them in significant risk.”