Abbott Labs says rapid tests can produce false negatives under certain conditions


Abbott Labs last week asked healthcare providers not to use solutions called “viral transport media” for samples tested on their ID NOW device, which performs one test at a time and can detect cases of positive coronaviruses in as little as five minutes and spitting out negative results in 13 minutes.

The company says customers should instead place swabs with patient samples directly into the device. When this method is used, the test works as “expected,” an Abbott spokesperson said, adding that when the company learned of the problem, it immediately informed its customers and the US Food and Drug Administration.

Abbott has promoted the ID NOW test as a “point of care” test, which means that medical offices or clinics can collect patient samples using pads and quickly test the samples without having to transport them to specialized laboratories.

Since the machine only processes one test at a time, laboratories may have used the transport stand to store the test samples until they can be processed. Abbott’s information about the test originally filed with the FDA listed a number of carriers that could be used with the test.

Clinical pathologists and laboratory scientists at the Cleveland Clinic said that the Abbott system produced higher false negatives than the other devices tested.

They processed more than 200 samples of Covid-19 using five test systems and discovered that ID NOW detected the virus in only 84.4% of the samples, a spokesperson for the based medical center told CNN. in Ohio.

ID NOW and another test had higher false negative rates than the other devices evaluated, said the spokesperson. NPR first reported on the assessment on Tuesday.

The Cleveland Clinic spokesperson told CNN that a dilution effect can occur every time a swab sample is placed in a viral transport medium, but added that in the assessment, ” all tests were done from the same viral transport medium, so it was a real leader – direct comparison. “

Abbott Laboratories guidelines come more than two weeks after President Donald Trump said at a press conference in Rose Garden that the company’s rapid coronavirus test would be “a whole new ball game” to expand testing for the disease.

Many hospitals, clinics and CVS test sites across the country have been able to use Abbott’s rapid tests.

The federal government has purchased devices for each state, and assistant health secretary Brett Giroir said last week that tens of thousands of other tests would be distributed to the poorest state labs.

The New York Northwell Health Labs, a private laboratory system serving state hospitals, use the Abbott test “in conjunction with” viral transportation.

A spokesperson told CNN, “We work closely with all of our suppliers to ensure the best possible clinical results. We are constantly evaluating our process throughout this crisis, which, as you know, is a dynamic and fluid situation. “

MedStar Health, a private hospital system located in Virginia, Maryland and Washington, DC, has avoided using viral transportation for rapid testing.

“Our lab teams have done extensive testing on the kits and we believe they are accurate,” said Marianne Worley, spokesperson for MedStar Health.

Nearly a month after Detroit mayor Mike Duggan negotiated an agreement to obtain five test devices and 5,000 tests, a mayor spokesperson said local health officials had not used any means of viral transport for samples tested on this system.

“We put them directly into the Abbott machine and do not transport them in a holder,” said the spokesperson.

Dave Koch, professor of pathology and laboratory medicine at Emory University, said it was “a remarkable achievement” that the Covid-19 assays came to market very quickly, but said it means that many typical validation experiments have not been completed.

“So test results can be influenced by something as simple as the medium of viral transport. This problem appears to have been identified, but other problems may arise, so caution is advised, “said Koch.

CNN’s Nicole Chavez contributed to this report.


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