As we continue to push through the coronavirus pandemic, the Centers for Disease Control and Prevention (CDC) is providing more information to ensure we make it through these unusual times in the safest way possible.
With states beginning to reopen across the country, more and more antibody tests have been conducted in an effort to inform people whether they may have previously had COVID-19.
Unfortunately, according to a report from CNN, the CDC is now saying those antibody tests are not very accurate. The CDC says that antibody tests should “not be used to make decisions” and that the results could be inaccurate up to half of the time.
“In the current pandemic, maximizing specificity and thus positive predictive value in a serologic algorithm is preferred in most instances, since the overall prevalence of antibodies in most populations is likely low,” the CDC says. “For example, in a population where the prevalence is 5 percent, a test with 90 percent sensitivity and 95 percent specificity will yield a positive predictive value of 49 percent. In other words, less than half of those testing positive will truly have antibodies. Alternatively, the same test in a population with an antibody prevalence exceeding 52 percent will yield a positive predictive greater than 95 percent, meaning that less than one in 20 people testing positive will have a false positive test result.”
The message was posted to the Interim Guidelines for COVID-19 Antibody Testing portion of the official CDC site.
The coronavirus mainly comes from animals and a majority of those who were infected early either worked at or frequently visited the Huanan seafood wholesale market in Wuhan, according to The Guardian. The virus is similar to Severe acute respiratory syndrome (Sars) and Middle Eastern respiratory syndrome (Mers).
The Wuhan coronavirus is transmitted from person to person through “droplet transmission.” That means an infected person can pass the virus by sneezing or coughing on another person as well as by direct contact.
While a majority of the cases have been detected in the United States and China — with more than 99,400 deaths in the United States — it has now reached many countries around the world. It has also been confirmed in Italy, Australia, Canada, France, Germany, and many other eastern countries.