The accuracy of the kits leaves much to be desired.
A review of at least 40 studies evaluating the accuracy of tests for antibodies (serological) after a person’s immune system fights SARS-CoV-2 coronavirus revealed that the fidelity of most kits have extremely large variations.
The document published on the portal of the medical journal TheBMJ reviewed the results of about 40 studies designed to analyze the accuracy of the multiple serological tests available. These tests reveal the presence of the specific antibodies that the immune system creates to fight the virus that causes COVID-19 disease. Although the tests are not used to determine if a patient is fighting an infection, they do show whether the person was ever infected.
However, the review of the studies, conducted in the United States, Japan, Italy and other countries, found several problems. The risk of a test yielding a false positive ranged from 66 to 97.8 percent. If 10 percent of a city’s population were infected, the researchers estimated that rapid testing would yield 31 false positives in 31 out of every 1,000 people, as were 34 false negatives.
Researchers advised governments to use this large-scale rapid testing to analyze their options closely. Although they take longer, molecular tests have been shown to be more effective in diagnosing contagion in people.