Antibody Testing for COVID-19
Several clients have questioned if they had #COVID-19 earlier in the year than the news reported we would have experienced this #virus in our country. Others are healthcare workers and are interested if they have immune protection, while others still, have interest in better understanding their immune system or want the understand their past exposure to help discern if they might choose to obtain the #vaccine into the future.
Here are a Few Points to Consider
MidAmerican Clinical Laboratories is reporting that current data shows IgG is detected in 98% of known PCR positive clients at 14 days of symptom onset. When we are looking for IgG antibodies, this is not a diagnostic tool as we are simply hoping to identify if there has been infection in the past. While this test is new, preference is given to those whose results might impact public health such as healthcare providers, public servants and others workers directly involved in the pandemic response.
Certainly with #immunizations becoming a point of contention with regards to individual rights verses protecting public health, it seems knowing one's individual status is in fact protecting public health whether essential or not. Each of us have visited the local hardware, grocery store, or local trails for hiking, most without masks.
Offering the antibody testing will help further assess the true rate of infection and return to work protocols, yet with limitations in who will be tested, results will be significantly skewed. We will be looking a population with high likelihood of exposure, not the general public's exposure and response. Further, it isn't simply the population that is limited, but confirmation of prior respiratory infection or known exposure with development of immune response is highly recommended prior to testing. This will limit our understanding of those who may have been exposed but never developed symptoms. Antibody testing will also support future vaccine development and convalescent plasma donor screening.
What does a Positive Result Mean?
This is indicative of an immune response to SARS-CoV-2 infection, the causative agent of COVID-19; however, it is unknown if the presence of IgG antibodies are indicative of protective immunity. The belief is this would be likely. A person with a positive IgG response has most likely been exposed to COVID-19 although there is slight chance of a false positive if one has had previous exposure to other common coronaviruses.
There are no formal guidelines for returning to work based on IgG testing, but there is thought that evidence of positive IgG and negative PCR prior to returning to work would reduce risk of transmission. A negative finding would suggest one has not acquired antibodies, which does not in itself rule out exposure or past infection with COVID-19.
If I test positive, can I spread COVID-19 to others if I don't have symptoms?
It is currently unknown when someone is no longer infectious or even how long they test positive after becoming infected. The CDC has found positive results in those infected beyond thirty days of symptoms. We often test IgM and IgG antibodies, with the IgM telling us there is current infection and IgG telling us the infection is gone, but was present at some point in the past. There is no formal guidelines on testing IgM or IgG with COVID-19, so it currently being offered to help better understand the prevalence and impact on public health.
Can I be tested?
Eden Family Practice can only provide testing for its current clients. If you are interested in being tested, contact your primary care provider. If you would like to initiate primary care with Dr. Lane, feel free to leave a voice mail and we can get a wellness consult scheduled.
Additional Information can be found here from the FDA and the ACLA offers a White Paper on Serologic Testing here.
What are my Options?
Several labs are now offering antibody testing for COVID-19; each are somewhat different. Some offer both IgM and IgG testing, while others are offering only the IgG. Turn around time differs as well as cost. Certainly one's insurance may dictate where one should be tested as well.
Test Code for COVID-19 IgG/IgA antibody Euroimmune assay testing with PathLabs (39432) is available now (as of April 24th). This is billable to insurance or available to cash paying clients for a reasonable fee. Into the near future, this lab will only run the IgG and eliminate the IgA antibody. Prices will remain the same. Current clients can call the office and request testing.
Diagnostic Solutions Laboratory made COVID-19 IgG/IgM antibody testing available on April 20th via serum, but the cost is nearly four times that of PathLabs. They also offer SARS-CoV-2 via stool analysis and COVID-19 diagnostic test via oral and nasopharyngial testing. Turn around time is 24 hours however, and PathLabs is a few days. If this interests you, please let me know so I can order kits.
Test Code for SARS-CoV-2 IgG antibodies with MidAmerica Clinical Laboratories (39504) is available through May 1st, only for healthcare providers. Testing should occur after a minimum of ten days from symptom onset to test. My preference is PathLabs.
Again, Eden's office line is 765-335-2171 if you are a current client and would like testing or would like to make an appointment as a new primary care client.