Coronavirus tests made by Thermo Fisher return false negative AND false positive results, FDA warns 

The US Food and Drug Administration (FDA) has issued a warning that a coronavirus test kit may return ‘inaccurate results.’

Health officials said on Monday there are two issues with the TaqPath COVID-19 Combo Kit produced by laboratory equipment company Thermo Fisher Scientific.

Firstly, the test, which detects the virus in respiratory samples, has had numerous complaints of false positive results due to not mixing specimen well enough.

Secondly, the software that clinicians use to the run the test is out-of-date causing results to come back as either false or inconclusive.

It comes on the heels of reports of more than 100 tests used in Connecticut and Kentucky revealed to be false positives.

The FDA has warned there are two issue with Thermo Fisher Scientific’s TaqPath COVID-19 Combo Kit (above)

Officials say the test has been improperly mixing samples, returning false positives, and has out-of-date software, returning false negatives. Pictured: A member of the clinical staff at Royal Papworth Hospital in Cambridge, England, cares for a patient in the ICU on May 5

Officials say the test has been improperly mixing samples, returning false positives, and has out-of-date software, returning false negatives. Pictured: A member of the clinical staff at Royal Papworth Hospital in Cambridge, England, cares for a patient in the ICU on May 5

On March 13, the FDA issued an emergency use authorization for the kit by Thermo Fisher, based in Waltham, Massachusetts, only to be used in laboratories.

The test is designed to detect nucleic acid from the virus, SARS-CoV-2, in upper respiratory specimens, such as nasal swabs.

According to Thermo Fisher Scientific, one kit can test up to 94 specimens and return results in under four hours.

However, officials received several consumer complaints related to ‘inadequate vortexing and centrifugation’ of the test.

The vortex mixes various samples of liquids rapidly and the centrifuge then separate the particles from a solution.

The FDA says that not mixing the swab with the solution well enough can lead to false positive results.

Last month, Connecticut’s Department of Public Health announced that between June 15 and July 17, Thermo Fisher’s test returned  least 90 false positives.

Dr Deidre Gifford, acting DPH commissioner, said almost all of the affected tests were taken from nursing homes or assisted living facilities.  

Officials say Thermo Fisher Scientific has updated instructions on how to use their kit to reduce the risk of inaccurate results.  

‘The updated instructions related to vortexing and centrifugation are important for both laboratories performing testing according to the authorized instructions for use and laboratories who are performing validated modifications outside of the authorization,’ the FDA wrote.

When tests return positive results, users are told to review to determine whether the plate should be retested due to inadequate vortexing and centrifugation. 

The second issue is that the software for the test is out-of-date and needs to be upgraded to reduce the risk of false or inconclusive tests.

Officials recommends laboratory staff stop using Applied Biosystems COVID-19 Interpretive Software version 1.2, v2.0 and v2.2. and upgrade to version 1.3 or 2.3. 

In mid-July, University of Kentucky Healthcare revealed it identified 26 false positive tests from the company due to a software issue. 

‘The FDA is working with Thermo Fisher Scientific and our public health partners to resolve these issues,’ the agency wrote on its website.  

‘The FDA will continue to keep clinical laboratory staff, health care providers, manufacturers, and the public informed of new or additional information.’

In the US, there are more than 5.4 million confirmed cases of the virus and more than 170,000 deaths. 

  

Read more at DailyMail.co.uk