Connecticut State Public Health Lab Discovers False Positive COVID-19 Test Results

Connecticut’s State Public Health Laboratory has uncovered a flaw in one of the testing systems it uses to test for SARS-CoV-2, the virus that causes COVID-19. The flaw, which has been reported to both the manufacturer and the federal Food and Drug Administration, led to 90 of 144 people tested during June 15–July 17, 2020 receiving a false positive COVID test report. The Department of Public Health (DPH) has taken immediate steps to make sure the patients are notified. The errant testing results were from a widely-used laboratory testing platform that the state laboratory started using on June 15. The exact cause of the false positive results is still being investigated. 

“We have notified the healthcare facilities for everyone who received a false positive test result from our state laboratory,” said Acting Commissioner Deidre S. Gifford, MD, MPH. “Accurate and timely testing for the novel coronavirus is one of the pillars supporting effective response to the COVID-19 pandemic. 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.” 

The false positive test results were discovered by DPH laboratory scientists during an examination of previously positive samples to determine the feasibility of testing “pooled” specimens at the state lab. The errant results are from test specimens processed between June 15 and July 17. The DPH state public health lab relies on this testing platform, but to ensure accuracy moving forward, all positive results will be further analyzed by multiple laboratory scientists, and if indicated, retested using another method. 

Medical providers and patients have been notified of false positive results. Many of the persons with false-positive test results are nursing home residents. Any nursing home resident with a false positive COVID-19 test result will be retested as soon as possible. DPH epidemiologists are reaching out to nursing homes again today to review all of the clinical issues for any impacted patients. 

The overall COVID-19 case numbers for Connecticut will be adjusted downward as a result of these false positive tests, provided that re-testing still shows the impacted individuals to be negative. Connecticut’s count of total positive cases will only be adjusted down for the number of people of these 90 who had received a false positive result and later tests negative. If someone previously received a positive result before receiving the false positive result, that person is still considered a positive case. 

A total of 161 lab specimens from 144 individuals showed positive results for COVID-19 using the platform during the period of June 15-July 17. Of those, a total of 91 specimens from 90 people showed false positive results.