Contamination and poor design failed CDC’s first COVID tests


The early failure of the CDC’s very first COVID-19 test kits was due to contamination and a design flaw, agency scientists said on Wednesday. This is the CDC’s first public explanation for the high-profile misstep at the start of the United States’ troubled pandemic response, detailed recently in a BuzzFeed News investigation.

In February 2020, the CDC sent a first batch of COVID-19 test kits to public health laboratories across the country, intended to help with surveillance for the new coronavirus. Within days, most test kits failed to pass standard measurements to verify they were working, returning false positive results. The failure of the kits was a nasty surprise at this early stage of the pandemic. The debacle grabbed the headlines and embarrassed the notorious public health agency for weeks, until states were allowed to conduct their own tests.

“It was like we were driving blind, and we were really kinda,” said Kelly Wroblewski, director of infectious disease programs at the Association of Public Health Laboratories, who was not involved in the report. While the failure to verify the test kits certainly did not cause the initial spread of the coronavirus in the United States, she added, “Those three weeks between the initiation of the initial test and then its failure and before we had really a new test available was a very, very long time.

The new test kit failure report, in the journal PLOS One, a non-CDC publication, attributes the false positives to contamination of the “N1” component of the test and an unrealized design flaw in its “component” N3 “.

The findings follow a June 2020 summary report from the Department of Health and Human Services that blamed a CDC research lab for the problems, suggesting that contamination in that lab caused the false positives in their components, rather than a design flaw.

The new study also follows last week’s BuzzFeed News investigation into the test kit’s failure with inadvertently published HHS interviews with lab staff. The investigation revealed emails suggesting that the contamination from a manufacturing lab (not the research lab) could have instead caused problems with the test kit, based on genetic evidence reported the last year at HHS.

The PLOS One report agrees with the BuzzFeed News investigation that genetic evidence points to early test development materials at CDC as the source of contamination. But it also suggests there was a design flaw in the test, as well as contamination, a new suggestion that was rejected in the HHS ‘first investigation of the test kits. Like the 2020 HHS survey, the study blames a CDC research lab for the contamination. Rather, the BuzzFeed News investigation found that a “deep clean” of a manufacturing lab made that larger lab a major suspect for the origin of the test kit contamination.

Because no genetic evidence of contamination appeared in the evaluations of the N3 part of the kit, the results of the study suggest that the N3 test suffers from a design flaw that causes it to give false positive results in validation tests.

Responding to a request for comment on the PLOS One study, a CDC public affairs representative responded with the statement: “Since the initial COVID-19 test rollout, the CDC has implemented corrective actions and remains dedicated to the highest quality and safe laboratory science. “The study did not explain why senior federal health officials relied on CDC labs to fabricate COVID-19 tests rather than engage with private test manufacturers to produce them for the United States.

Based on the study’s analysis, the new findings of contamination and a design flaw are plausible, University of Washington laboratory testing expert Geoffrey Baird told BuzzFeed News via email. But the analysis doesn’t reveal exactly when the contamination was introduced, which we may never know. “The question of when (in which lab) the N1 contaminant was introduced is not really something that seems to be known on the basis of chemical analyzes,” Baird said.

For now, the N3 component of the CDC test remains on sale to testing companies; the CDC did not issue any sort of warning regarding the suspicious design flaw described in the study. An August 2020 report from CDC lab officials simply said the N3 component had been removed from its official test because analysis showed the test was just as effective without it, rendering it redundant.

In retrospect, the problems with the CDC’s test kits are less surprising than they were at the start of the pandemic, Wroblewski said. Normally, the design, validation and manufacture of diagnostic tests take months or years. But, she said, it’s important to understand exactly how they failed in this case “for the sake of transparency, and perhaps to restore some confidence in the agency.”


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