National coronavirus test shortages have emphasized testing’s critical role in containing and mitigating the pandemic, but these inconvenient truths remain: A test result is rarely a definitive answer… The result itself may be falsely positive or negative, or may show an abnormality that doesn’t matter. And even an accurate, meaningful test result is useless (or worse) unless it’s acted on appropriately.
Coupled with genuine uncertainty about an emerging disease and a political environment that has sown misinformation and rendered science partisan, the nuances of testing are too often lost at a time when they are particularly crucial to convey.
Jasmine Marcelin, who specializes in infectious disease at the University of Nebraska Medical Center, was concerned to see Nebraskans tested at statewide facilities get “inconsistent results without a lot of guidance or explanation about what these results might mean.”
A negative antibody test could mean you were never infected with the virus, or it could mean that you’re currently infected but haven’t yet built up that army, or that these defenses have already faded away.
A positive test, on the other hand, may have mistakenly detected antibodies to another, similar-looking virus. And even if the test correctly shows you had covid-19, it’s not yet clear if this means you’re protected from reinfection.