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We Know Kids
The Willows Pediatrics Blog

In Office Covid-19 Testing for Symptomatic Patients: Rapid Antigen Test And PCR Test

Rapid Antigen Covid-19 Testing

Covid-19 SARS antigen test box
Willows Pediatrics
has the ability to do rapid COVID-19 testing. This is performed with the rapid lateral flow assay made by Quidel using Sofia 2 test kits. A sample is obtained from the lower part of your child’s nose using a nasal swab. We run the test in our office. Parents receive results within the same day. (If the sample is obtained very late in the day, in those instances we may run your rapid antigen test shortly after the office opens the next morning. Swabs may be kept overnight and run the next morning).

There are a few limitations:

Covid-19 rapid in-office testing available at Willows Pediatrics

  • The rapid Covid-19 test is not recommended for testing asymptomatic individuals`because it may not detect low viral loads. For these individuals, the PCR test is the most accurate.
  • If your child is sick and the rapid Covid-19 test is negative, but symptoms increase or persist, we may recommend that your child also have a PCR test done.
    • Please note: We cannot do a Rapid Test and a PCR Test on the same patient on the same day
  • Rapid testing is not available on Saturdays because a lab tech is not in the office. We can, however, obtain a nasal swab on Sundays and have your child’s test run shortly after the office opens the following day, Monday.

How accurate is the rapid Covid-19 test?

  • In symptomatic individuals, the rapid test detects over 80% of individuals with a Covid-19 infection. Studies have shown rapid antigen Covid-19 tests have a sensitivity ranging from 84.0% – 97.6% compared to PCR testing. However, Covid-19 antigen levels in swabs collected 5-7 days after the onset of symptoms may drop below the limit of detection of the test.
  • In asymptomatic individuals, the rapid test may only detect a third of the positive cases compared to PCR testing

More details on the accuracy of rapid COVID-19 tests is available here.

PCR Covid-19 Testing

Unlike the rapid test, which looks for bits of coronavirus proteins, or antigens, the PCR test is a molecular test that detects genetic material of the coronavirus. PCR tests can detect ultra-low levels of viral RNA, which is why PCR tests are recommended for asymptomatic individuals who may not have enough viral load to be detected by the rapid test. PCR testing can also be done on people with symptoms.

If your child needs a PCR Covid-19 test, a sample is obtained from the lower part of your child’s nose using a nasal swab. This swab is sent to Quest labs, and your child should quarantine until the results come back. The turn-around time for results vary; it typically is 48-72 hours, but may be longer. Since we send the PCR test to Quest labs, we do not have control over when the results are available. (Please note, for individuals who have a Covid-19 PCR test because of an exposure, a negative PCR does NOT mean they can shorten the recommended quarantine period.)

How accurate is the PCR Covid-19 test?

PCR tests have a sensitivity and specificity greater than 95%. This means the chances of a false negative or a false positive are less than 5%.


We submit the cost of the Rapid Covid-19 test to your insurance. When the PCR test is done, Quest Labs submits the bill for the test to your insurance. Please note, Husky Health does not cover the rapid Covid-19 test. Children or adolescents covered by Husky Health needing Covid-19 testing must have the PCR test done.