COVID-19 Testing: PCR vs. Rapid - What's the Difference?

March 16, 2021
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So you’re finally allowed to reopen… now what?

There are so many different things to consider when developing your camp reopening plan, and one of the most important is creating an effective COVID-19 testing strategy.

There are many testing options available these days, and they can vary significantly in cost, result time, and their ability to accurately detect infection.

The most common tests used to screen for COVID-19 are polymerase chain reaction (PCR) and rapid tests.

How do they differ? When should I use them?  How do I know I’m choosing the right test for my staff and campers?

Types of Tests Used to Detect Active Infection 

Nucleic Acid Amplification Test (NAAT)

(e.g. Molecular tests, PCR Tests, viral RNA Test)

Antigen Test 

(e.g.  Rapid Test, Rapid Antigen Test)

What does it look for?
Genetic material (nucleic acid) specific to the virus

Where is it collected from?
Back of nose, front of nose, throat, saliva, or lungs

Average Sensitivity
85–95%

How long for results?
Hours to days

What does it look for?
Protein fragments (antigens) from the virus

Where is it collected from?
Back of nose, throat, or saliva

Average Sensitivity
50–70%

How long for results?
Minutes to hours

Sensitivity means how often the test generates a positive result for people who actually have a COVID-19 infection.

Did you know?

Compared to PCR tests, antigen tests are more likely to miss an active COVID-19 infection early in its course or due to low viral load. If infected and asymptomatic for COVID-19, a PCR test is likely to detect the virus. A PCR test can detect infection at lower levels than a rapid antigen test. 

What are the advantages of rapid antigen tests and when would it make sense to obtain them?  

Rapid antigen tests can be conducted onsite, provide results quickly, and are typically less expensive than PCR tests. They are acceptable to confirm a diagnosis when someone has symptoms of COVID-19. Rapid antigen tests can aid in screening persons in congregate settings, such as residential housing communities, or those with repeated exposures, such as frontline workers, if done daily or multiple times per week to detect infection and take immediate steps to prevent further transmission.

What are the disadvantages of rapid antigen tests and when would it be less appropriate to obtain rapid antigen testing?

Antigen tests are typically not as reliable as PCR tests in screening for COVID-19 infection in communities with low rates of infection or in individuals who are asymptomatic. If an individual has symptoms of COVID-19, a positive antigen test can be used to confirm infection, but if the antigen test result is negative, a PCR test should be conducted. If there is a discrepancy between the two tests, the PCR test result should be relied upon for diagnosis as it is considered as the “gold standard.”

Sources:

This blog post was provided by Heed Health. Heed Health partners with clients to provide COVID-19 Testing, Monitoring, and Advisory solutions.

Periodically, the American Camp Association (ACA) makes timely and relevant information about products and services available to its members so they can make informed decisions for their camps. However, the ACA does not endorse products, services, or companies.