CDC: Coronavirus tests were poorly designed
The faulty coronavirus testing kits developed by the Centers for Disease Control and Prevention in the early weeks of the pandemic were not only contaminated but had a basic design flaw, according to an internal review by the agency.
Health officials had already acknowledged that the test kits were contaminated, but the internal report, whose findings were published in PLOS ONE on Wednesday, also documented a design error that caused false positives.
The distribution of faulty test kits, at a time when no other tests were authorized, set back health officials’ efforts to detect and track the virus.
“It delayed the availability of more widespread testing,” said Dr. Benjamin Pinsky, director of clinical virology for Stanford Health Care. He added, “I think it’s important that they got to the bottom of what went wrong.”
In January 2020, the CDC developed a polymerase chain reaction, or PCR, test for the virus. PCR tests, which are performed in laboratories, can detect the virus at very low levels and have been considered the gold standard for diagnosing a coronavirus infection.
Problems emerged soon after the CDC had begun shipping its test kits out to public health laboratories in early February. Within days, many labs were reporting that the tests were generating inconclusive results.
In mid-February, the agency acknowledged that the kits were flawed, and in April, officials at the U.S. Food and Drug Administration said that poor manufacturing practices had resulted in contamination of the test kits.
The new paper presents the results of the CDC’s own internal investigation into the problems with the tests.
The CDC’s test was designed to detect three distinct regions, or target sequences, of genetic material in the virus. The test kits contain a set of what are known as primers, which bind to and make copies of the target sequences, and probes, which produce a fluorescent signal when these copies are made, indicating that genetic material from the virus is present.