The Wyoming Department of Health (WDH) is encouraging residents with COVID-19 symptoms to get tested to help prevent further spread and outbreaks, but to also be aware of different types of testing and what they may or may not be able to reveal.
Dr. Alexia Harrist, state health officer and state epidemiologist with WDH, said testing is more available now than at other points of the pandemic.
“We want anyone with symptoms that could be COVID-19 to ask about testing,” she said. “Identifying individuals with COVID-19 helps us track this disease. No one should avoid testing out of fear. Knowing what’s going on in Wyoming is good for all of us.”
“If you have symptoms we recommend you call ahead to your healthcare provider for advice and to make arrangements,” Harrist said. Decisions about which patients should be tested are usually made by healthcare providers, partially based on WDH guidance.
Viral tests and antibody tests are the two primary types of tests currently available for COVID-19. “The short answer on the difference between them is a viral test can show if you have a current infection while an antibody test might show if you had a past infection,” Harrist said.
Viral tests typically use samples gathered with swabs from inside the nose. Some viral tests allow quick results at the same location where the sample is collected. With others, samples are sent for analysis to a laboratory such as the Wyoming Public Health Laboratory. “This type of testing is most accurate and most important for when you are sick,” Harrist said.
People who test positive for COVID-19 should follow advice available from WDH meant to help prevent spreading illness.
“If you test negative, you probably were not infected at the time your sample was collected and there is likely another cause of your symptoms. However, it’s also possible your sample was collected early and you could test positive later because it can take up to 14 days after exposure to COVID-19 for someone to become ill,” Harrist said.
Antibody tests involve blood samples and should not be used to find out whether someone is currently sick with COVID-19, but may reveal an earlier infection.
Harrist said people should know not all antibody tests are reliable and providers should be cautious when choosing antibody tests to ensure they've been properly evaluated.
Harrist emphasized it isn’t known yet if having antibodies to the COIVD-19 virus can protect someone from getting infected again or how long any possible protection might last. “It’s unclear whether COVID-19 antibodies can provide immunity against getting future infections. A positive antibody test result should not be viewed by anyone as a ‘free pass’ or guarantee against new illness,” she said.
“It can take 1-3 weeks after you are infected with a virus for your body to make antibodies. That’s why it is not a good method to see if you are currently ill,” Harris said.
If a reliable antibody blood test is used, a positive result can show a person has antibodies that likely resulted from an earlier COVID-19 infection. Some people might test positive without ever experiencing symptoms.
Individuals who test negative for COVID-19 with a reliable antibody test probably did not have a previous infection with the virus that has since gone away. “We know many people are curious to know whether an episode of illness they had earlier this year was actually due to COVID-19,” Harrist said.
For more COVID-19 information and recommendations visit: https://health.wyo.gov/publichealth/infectious-disease-epidemiology-unit/disease/novel-coronavirus/.