COVID-19 (SARS-CoV-2) Testing
Tomorrow’s Health provides one of the most sensitive real-time PCR (RT-PCR) tests for SARS-CoV-2 currently available: able to detect down to 150 virus particles per milliliter (mL) of patient specimen.
This test is offered as an individual (single) or a pooled test. See below recommendations for when the single or pooled test should be ordered:
Individual SARS-CoV-2 test.
This is the most sensitive form of the test and should be ordered when:
- A patient has COVID-19 like symptoms
- There is high suspicion that an individual has COVID-19, even when they are not showing symptoms (e.g., close contact with a COVID-19 positive person)
Pooled SARS-CoV-2 test.
Tomorrow’s Health will be pooling three (3) specimens together in this form of the test. Thus, this test is less sensitive than the individual test and should only be ordered when/for:
- There is a low likelihood (chance) that the individual has COVID-19
- Screening of large numbers of individuals where the prevalence of COVID-19 infection is expected to be low (<5%) (e.g., regular screening of employees, students, etc.)
SARS-CoV-2 antibody (IgM and IgG) test.
- Tomorrow’s Health is performing a rapid, fingerstick test that detects both IgM and IgG in your blood.
- The presence of antibody may mean that you currently have COVID-19 or have had it in the past
A negative test does not completely rule out current or past COVID-19 infection, as antibodies do not appear early in disease (i.e., within the first two weeks) and decrease over time after infection (i.e., months to years later)
Why Choose the COVID-19 PCR Test Offered at Tomorrow’s Health over a COVID-19 Rapid Antigen Test?
Since the beginning of the COVID-19 pandemic, lab testing has been a very important tool in slowing down the spread of this terrible virus. However, it is important to know that there are big differences between the various lab tests that are available right now. The most common types of lab tests include the PCR (polymerase chain reaction) test and the rapid antigen test.
Though it is important to get a test result as quickly as possible, it is even more important to get an accurate result. The rapid antigen test can be turned around rapidly, but the PCR test has proven to be much more accurate. The below table compares the speed and accuracy of the PCR and antigen tests currently available.
|Covid-19 Test Type||Time to Result||Accuracy|
|Rapid Antigen||15-30 Minutes||Sensitivity: 60%
*Overall Accuracy: ~80%
|PCR||1-7 days||Sensitivity: >90%
Overall Accuracy: ~95%
|PCR at Tomorrow’s Health||0-1 day (same day or next day)||Sensitivity: >90%
Overall Accuracy: ~95%
A: Tomorrow’s Health provides one of the most sensitive, real-time PCR (RT-PCR) tests for COVID-19 currently available, with the capability to detect as low as 150 virus particles per milliliter (mL) of patient specimen.
A: The PCR test must be performed by trained technicians in a molecular testing laboratory using sophisticated procedures and equipment. Because we perform the PCR testing in-house at Tomorrow’s Health, we can give results relatively quickly. Most other COVID-19 testing locations in the Tri-Cities area send the specimens out to another location for testing.
A: The PCR test is considered the gold standard for COVID-19 (and many other infectious disease) testing. The PCR test is almost always the type of test required for surgical or other medical procedures, being cleared to go back to work or school, traveling, or attending sporting or other events.
A: Sensitivity is the ability of a test to detect the virus when it is actually there. When a test has lower sensitivity, it means there will be more “false negatives”, instances where the virus was really there, but the test did not detect it. Specificity is the ability of a test to give a negative result when the virus is NOT there. When a test has lower specificity, it means there will be more “false positives”, instances where the virus is NOT really there, but the test is positive for the virus.
A: Rapid antigen tests look for the proteins found in the virus. Because these proteins are constantly changing, creating new “variants” of the virus, the rapid antigen tests become less able to detect these changed proteins. PCR tests look for pieces of RNA (ribonucleic acid, the virus’s genetic material) in the virus that don’t change very much, even in these “variants”.e a negative result when the virus is NOT there. When a test has lower specificity, it means there will be more “false positives”, instances where the virus is NOT really there, but the test is positive for the virus.