Connecticut discovers at least 90 false positive coronavirus tests

Coronavirus testing in Connecticut returned at least 90 false positives due to a “flaw” in the state’s testing system, Connecticut’s Department of Public Health announced Monday.

A total of 144 people tested positive using a system developed by Massachusetts-based Thermo Fisher Scientific in the period between June 15 and July 17, the department said. Nearly all of the tests affected by the flaw were taken from residents of nursing homes or assisted living facilities, according to acting Public Heath Commissioner Deidre Gifford.

“This [error] is going to apply to a minority of tests in the state,” Gifford said, according to the Hartford Courant. “Anybody who’s received a positive test, they should absolutely assume that that positive result is correct until such time as they are informed by their provider of any change.”

Of the more than 650,000 tests the state has conducted since March, Gifford said only a small percentage of tests would have been affected by the error, and that people who received a positive result should in general assume it was accurate. The state began using the Thermo Fisher system on June 15.

Public health lab director Jafar Razeq said the lab discovered the issue with the tests while looking at raw testing data to validate pool testing.

“When we started looking at the background information on these specimens, we realized that these specimens should have not been reported as positives,” he said. “That was alarming.”

The team pulled all of the system’s positive tests, which comprised 161 specimens from 144 patients out of more than 2,200 total samples.

“If it had not been for us looking into the pool testing to use some of these previously known positive samples, there were no indications that any of these reported positive results would have been questioned,” he said. “There [was] nothing for us to question the results that we had, if it was not for the pool testing.”

Gifford said the department has made corrections based on the discovery.

“Thanks to the quick action of our team at the state lab, adjustments have already been made to ensure the accuracy of future test results from this platform,” she said, according to the Courant.