CDC Warns Of Antibody Test Accuracy:” It Can Lead To False-Positives”

According to the US Center for Disease Control and Prevention, people should be aware of antibody test results. Although it is used to determine if someone has been infected with the coronavirus in the past, the results, however, are sometimes incorrect.⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

Also known as serologic tests, antibody tests test for traces of an immune response to infection. In some people, it can be found within the first week of being diagnosed with COVID-19, the CDC states. But, due to its lack of accuracy, the new guidelines recommend that the test is not used when making important policy decisions.⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

“Serologic test results should not be used to make decisions about grouping persons residing in or being admitted to congregate settings, such as schools, dormitories, or correctional facilities,” the CDC says. “[Also] serologic test results should not be used to make decisions about returning persons to the workplace.”⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

Because of this, health officials that decide to use the antibody test should make sure that they’re using the most consistent test that they can locate. Even then, doctors will more than likely have to test people more than once, the CDC mentions.⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

The CDC also notes that in several areas within the country, the antibody is projected to be low, which could lead to more people who get tested to believe that they have the disease but don’t.

“In most of the country, including areas that have been heavily impacted, the prevalence of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) antibody is expected to be low, ranging from less than 5% to 25%, so that testing at this point might result in relatively more false-positive results and fewer false-negative results.” ⠀⠀⠀⠀⠀⠀⠀⠀⠀

The bigger the sensitivity, the less false negatives a test will provide, CNN stated. The higher the specificity, the less false positives. A false positive has the ability to have someone assume that they are infected with the coronavirus when In fact, they are not.⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

“Therefore, its best to use tests with high specificity, which are unlikely to throw up a lot of false positives, and in populations where doctors suspect there are many cases,” the CDC states.