Edward Espinosa, DO, MPH – Medical Director, Buckhead Medicine
As the country begins to emerge from the total shutdown imposed to control the exponential spread of the COVID-19 virus, widespread testing becomes key to controlling the community spread of the virus. In the past 8 weeks there has been widespread coverage in the media on the variety of COVID-19(Coronavirus) tests being introduced into the market and their accuracy and reliability. As highlighted in a previous blog, with the prevalence of coronavirus infection running at about 5% in the general population, test manufacturers and regulators alike will have to guard against a high rate of false positives from these tests.
To determine contraction risk, the antibody tests for short and long term immunity to Coronavirus become important. If an individual test is positive for short term antibodies (IgM) it implies that they are in a convalescence phase, recovering from an active infection from the virus. Testing positive for long term antibodies (IgG) indicates that the individual has had an infection in the distant past. This confers a degree of immunity for re-infection. The higher number of tested individuals within a group that have antibodies present, the increased likelihood of conferring immunity against re-infections or minimizing the degree of re-infection. Considering the utility of such tests in providing guidance with regards to contraction risk these tests become important for employers to assess and evaluate returning to work front-line workers.
In spite of the utility of antibody tests, a key question remains regarding their accuracy and reliability, since they have been released onto the market with very little regulatory oversight. This is however about to change, with the FDA, CDC and NIH saying last week that they will work together to validate the accuracy of the tests on sale in the US. The article referenced below provides an excellent overview of the accuracy of the current tests on the market.