The U.S. FDA posted an advisory directed to clinicians and others regarding false positive test results for antigen tests administered for detection of the SARS-CoV-2 virus. The agency said these tests, which are authorized for qualitative detection of the virus, have returned some false positive results, an outcome that is expected when a highly accurate antigen test is administered as a screening instrument in a geographic area with a low prevalence. The agency went to some lengths to advise health care professionals and nursing home staff that compliance with the test label is critical to obtaining an accurate result, including in the context of the elapsed time between test administration and reading of test results. Incubation times are more likely to be allowed to drift out of spec when multiple specimens are incubated in a single incubation run, and inappropriate cycling of personal protective equipment can contaminate specimens. Positive antigen test results may be followed up with a real-time PCR test within 48 hours, particularly in counties with a low disease incidence, and the FDA spelled out several positive predictive value parameters based on local disease prevalence. The FDA has made a point of communicating these and other related issues during the weekly COVID-19 testing town hall as well.

FDA announces recall of discontinued Medtronic catheter

The FDA said the class I recall of the Rashkind balloon septostomy catheter was undertaken due to quality issues that could lead to device breakage, separation or failure during use, which could lead to vascular injury or death. The agency did not specify the quality issues that led to the recall, but noted that the manufacturer, Medtronic plc, of Dublin, has ceased the manufacture and distribution of the Rashkind for “reasons unrelated to this recall.” The recall affects 142 devices in three sizes distributed in the U.S. between May 28, 2018, and Aug. 28, 2020.