Getting COVID-19 tests can be challenging for some employers, especially considering the rapid evolution of testing guidance on all of the different testing options. While each test has its own limitations, molecular tests are perhaps the most effective.
Of the three main types of tests for COVID-19, two are diagnostic (PCR and antigen tests), and one looks for protective antibodies from a previous infection (antibody or serologic tests).
1. RT-PCR
This is the most common test that is frequently used to detect the virus’s genetic material in the body. Using this test, patients can know whether or not they have an active COVID-19 infection and can adjust their lifestyle accordingly (i.e., quarantine).
Pros:
- Minimally invasive
- Allows for social distancing
- Fewer false negatives in some instances
Cons:
- Long turnaround times
- False negatives
- Uncomfortable for some people
2. Antigen Tests
Performed using a nasal or throat swab, helps detect specific protein fragments residing on the surface of the virus.
Pros:
- Rapid results: The test uses technology similar to that used in a pregnancy test and yields results within minutes
Cons:
- Performed at a hospital or clinic: At-home antigen tests are not widely available, so patients typically have to travel to a hospital or clinic to have this test performed
- High false-negative rate
3. Antibody Tests
This test is also known as a serological test, blood test, or serology test. It involves taking a sample with a finger stick or blood draw.
Pros:
- Offers more timely and convenient results
Cons:
- Not effective for diagnosing an active coronavirus infection
- There is not enough sufficient evidence to suggest that the presence of these antibodies determine that the immune system is protected from future exposure to a coronavirus
Popular Testing Method: Pooled Sample Testing
Pooling samples involves mixing several samples together in a "batch" or pooled sample, then testing the pooled sample with a diagnostic test.
Pros:
- Increases the number of individuals that can be tested, using the same amount of resources
- Works well when there is a low prevalence of cases, meaning more negative results are expected than positive results
Cons:
- Because samples are diluted, which could result in less viral genetic material available to detect, there is a greater likelihood of false negative results, particularly if not properly validated
- Cost of high volume if batches come back positive--if/when an individual in the pooled sample tests positive, all 4 individuals will need to re-test individually
Knowing the pros and cons of RT-PCR, antigen, antibody, and pooled testing can help you decide what's best for your company. However, while there are several different types of COVID-19 testing, some are more accessible than others. Testing on a mass level can also be difficult, so it's best to partner with a vendor who can help you successfully implement COVID-19 tests.
Want to learn more about COVID-19 solutions for your company?
For more information on what you can be doing to reduce the spread of COVID-19 in your workplace, download our checklist today!
