Chester County will notify thousands of ‘questionable’ COVID results

A nurse prepares to process a COVID-19 testing kit for results. (Eman Mohammed/NPR)

A nurse prepares to process a COVID-19 testing kit for results. (Eman Mohammed/NPR)

A Pennsylvania county has acknowledged that tests it purchased from a local biotech start-up produced “potentially inaccurate” results for thousands of people.

Chester County vowed this week to reach out to those who received the “questionable test results” in late May and to appoint a consultant to review the purchase of the antibody tests, The Philadelphia Inquirer reported.

The news comes days after the newspaper reported that the county spent $13 million in federal pandemic aid on a no-bid contract to Malvern-based Advaite. The testing program was intended to identify essential workers who had developed disease-fighting antibodies, which show up in the blood after COVID-19 infection.

In the first few weeks after testing began May 7, the tests produced results that appeared to be accurate. But two weeks later, the percentage of people testing positive for coronavirus antibodies began spiking to levels far above what was plausible, based on the prevalence of the virus in the area. The county eventually shelved the program June 2.

The U.S. Food and Drug Administration says antibody tests should not be used to diagnose COVID-19. But Chester health officials and their lab partner decided to interpret certain results as signaling a current infection. Patients with those results received emails stating: “You may have COVID-19. You are likely contagious. You should isolate yourself at home.”

The county, though, never informed those who may have received false alarms, nor did it disclose the questionable results — about 6,100 of the 19,425 tests it conducted — on its website.

Chester County said Tuesday that its three-member Board of Commissioners would appoint an “independent legal consultant” to review the process associated with sourcing and procuring the antibody tests.

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