Clearly, more widespread testing for coronavirus, both active infections and past infections, will be invaluable as we work to reopen our economies as safely and quickly as possible. At IHM, we are monitoring every test as it comes available, and evaluating it for efficacy.
Testing for Active Infection
At this time, we are not aware of a test for active infection that is available to the general public. We are hoping home test kits will be available soon and that we will be able to send these to our patients. Until then, the best option for testing is through facilities that provide care for COVID or through state health departments.
Antibody Testing for Prior Infection/Immunity
Antibodies develop after we have been exposed to a pathogen. So far, research suggests that within about 1-2 weeks after symptoms start, IgG antibodies to coronavirus can be detected. It stands to reason that a simple IgG antibody test will tell you that you’ve had the infection and are immune, so can safely resume normal interactions with society. Unfortunately, that is not the case.
Antibody tests for coronavirus are being released without FDA approval and are not being held to the usual standards for accuracy. Data on coronavirus is obviously in its infancy, so what we know now is likely to evolve and may change completely.
Two major issues exist with IgG antibody testing. First, we don’t know whether antibodies actually confer immunity. With many coronaviruses, such as those involved in the “common cold,” people can get reinfected. Also, many coronaviruses are known to change and thus evade prior immunity. Without further research, we cannot extrapolate that the presence of antibodies means someone is immune. It might… but we just don’t know yet.
The other concern is that the tests have a high false positive rate because they often detect other coronaviruses, not just SARS-CoV-2. This means a positive test may not mean that you have been exposed to the SARS-CoV-2 coronavirus, but instead to some other coronavirus.
What We Recommend
At this time, we are not aware of a test for active infection that is available for us to order for the general public, and we have not found an antibody test that delivers the sensitivity and specificity we need to trust the results, nor do we know if a positive test confers immunity. We are actively monitoring tests as they become available, and we will be ready to offer testing as soon as reliable and meaningful tests are available for us and our patient population.
As we’ve said, the best tests you can do right now are measuring vitamin D levels, inflammation levels (hsCRP), and tests to check for diabetes or prediabetes (CMP, HgbA1c). These are all risk factors for a worse infection, and they are all things we can address with diet and supplements.
We thank you for your trust in IHM and look forward to providing the highest quality care possible as the coronavirus situation continues to unfold.