For individuals with COVID-19 symptoms, they should have a COVID-19 test administered whenever possible. People who have no symptoms yet have had close contact with someone who is, or might be, infected should also take a test, contact local health facilities and follow their guidance.
While waiting for test results, one should remain isolated from others. COVID-19 tests will first be administered for those at higher risk of infection when limited tests are available. Those who are high risk include health workers and those at higher risk of severe illness, including older people, particularly those residing in seniors’ residences or long-term care facilities (World Health Organization, 2021).
What test will reveal if someone has COVID-19?
In nearly all circumstances, a molecular test confirms infection of SARS-CoV-2. Polymerase chain reaction (PCR) is the most commonly used molecular test. Molecular tests detect viruses in the sample by amplifying the viral genetic material to measurable levels (Jayamohan, 2020). Thus, a molecular test will verify an active infection, usually within three to five days of exposure, and around the moment symptoms may begin (Winkelhake, 2021).
Learn more about what kind of COVID-19 tests are available.
What about rapid tests?
Rapid antigen tests are occasionally known as rapid diagnostic tests (RTDs). These rapid diagnostic tests detect viral proteins, otherwise referred to as antigens (Groth, 2020). Rapid antigen tests are not as expensive as PCR and offer quicker results. Even though they are generally less accurate, these tests function best when there is more virus spreading in the community, and when sampled from a person when they are highly contagious (World Health Organization, 2021).
What test will reveal if someone had COVID-19 in the past?
Also known as serological tests, antibody tests will show whether an individual has had a previous infection, even if they had no symptoms (Center for Disease Control and Prevention, 2020). COVID-19 antibodies are present in persons with past disease, and an antibody test will confirm such. Antibody tests cannot diagnose COVID-19 in the early stages of infection. This sort of test can only determine past COVID-19 infections (World Health Organization, 2021).
Center for Disease Control and Prevention. (2020, November 03). Serology Testing.
Retrieved from Center for Disease Control and Prevention: https://www.cdc.gov/coronavirus/2019-ncov/lab/serology-testing.html
Groth, L. (2020, 12 May). What Is a Coronavirus Antigen Test — and How Is it
Different Than Antibody Testing? Retrieved from Health: https://www.health.com/condition/infectious-diseases
Jayamohan, H. (2020, October 18). SARS-CoV-2 pandemic: a review of molecular
diagnostic tools including sample collection and commercial response with associated advantages and limitations. (Department of Engineering, Producer, & University of Utah) Retrieved December 10, 2021, from PubMed: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7568947/
Winkelhake, H. (2021, September 03). Norton Healthcare. Retrieved from How Long
Does It Take After Exposure To Test Positive For COVID-19?: Retrieved from Norton Health Care: https://nortonhealthcare.com/news/how-long-after-exposure-to-test-positive-for-covid/
World Health Organization. (2021, May 13). Coronavirus disease (COVID-19).
Retrieved from World Health Organization: https://www.who.int/news-room/questions-and-answers/item/coronavirus-disease-covid-19