Some testing kits for 2019-nCoV sent out by the US Centers for Disease Control and Prevention are giving inconclusive results during quality control checks, leading the agency to have to re-manufacture one of the kits' reagents, as GenomeWeb reports.
A positive result on the test, which is real-time RT-PCR based, indicates a likely infection with the 2019-nCoV coronavirus, though a negative result does not fully rule out possible infection. The Food and Drug Administration issued an Emergency Use Authorization for the test last week to enable other labs than the CDC in Atlanta to use it. According to the New York Times, the CDC began last week to ship about 200 kits to labs in the US — each kit can test about 700 to 800 patient samples — and a similar number internationally, though the international shipments were held as this issue was uncovered.
As GenomeWeb reports, when state labs were conducting quality assessment and validation checks of the test, they encountered inconclusive results. The CDC says it traced the issue to a reagent that wasn't working properly and will be re-manufacturing that reagent. "Obviously a state wouldn't want to be doing this test and using it to make clinical decisions if it isn't working as perfectly at state [labs] as it is at CDC," Nancy Messonnier, the director of the National Center for Immunization and Respiratory Diseases, said during a news conference.