Testing for COVID-19 has tremendous value when it comes to trying to contain the spread of the COVID virus. According to Dr. Joseph Bustamante, Chief Medical Officer at Memorial Healthcare, "The variety of virus that causes COVID-19) available today can be rather confusing. There are some clear indications as to which test you should get and some not so clear reasons."
There are essentially two broad categories of testing. (frequently referred to as a rapid test). This test detects protein fragments specific to the Coronavirus. It can be done in a clinic, doctor's office, or hospital. Turnaround time for results is usually very quick and in some cases, results can be reported within 15 minutes. The other is PCR testing, which is considered the "gold standard" in SARS-CoV-2 detection. This test actually detects RNA (or genetic material) that is specific to the virus and can detect the virus within days of infection, even those who have no symptoms. The test can be done in a clinic, hospital, or even in your car. Turnaround time is longer, generally in the 2-3 day range but results can be in as little as 24 hours. When demand is high, results can take a week or longer.
Rapid tests are considered most accurate in a patient who is having symptoms of COVID-19. While the rapid test can get you results very quickly, the results may not always be accurate. It may meet the situation of false negative or false positive. In those who don't have symptoms, the false negative rate - meaning my test is negative but I actually have the disease — can be as high as 50%. This can have tremendous consequences as we try to contain the spread of COVID-19.
The false positive rate - meaning I test positive but I do not really have the disease - is quite low. So, if you test positive from a rapid test it is more likely you do have the disease. Current recommendation is to have a confirmation test performed (the PCR test) if you still have symptoms and have had a negative rapid test. This is especially true if you've had a high-risk exposure. A high risk exposure is considered more than 15 minutes of contact with a COVID-positive individual in a 24-hour period and you have been within 6 feet of this individual.
Covid 19 Antibody Rapid Test, also known as serology testing, is usually done after full recovery from COVID-19. Eligibility may vary, depending on the availability of tests. A health care professional takes a blood sample, usually by a finger prick or by drawing blood from a vein in the arm. Then the sample is tested to determine whether you've developed antibodies against the virus. The immune system produces these antibodies — proteins that are critical for fighting and clearing out the virus.
The timing and type of antibody test affects accuracy. If you have testing too early in the course of infection, when the immune response is still building up in your body, the test may not detect antibodies. So antibody testing is not recommended until at least 14 days after the onset of symptoms. The U.S. Food and Drug Administration (FDA) authorized specific antibody tests, but tests with questionable accuracy are still on the market.
Another benefit of accurate antibody testing is that people who've recovered from COVID-19 may be eligible to donate plasma, a part of their blood. This plasma could be used to treat others with severe disease and boost the ability to fight the virus. Doctors call this convalescent plasma.
