Some of you, especially if performing high cadence surveillance testing, could come across  this scenario.

NY Times article: 

These Researchers Tested Positive. But the Virus Wasn’t the Cause.

Several scientists working with harmless genetic material have discovered that their research may have contaminated their coronavirus tests.

https://www.nytimes.com/2020/11/12/health/coronavirus-testing-lab-contamination.html

Mary Julie Corrigan, SM, CIH

Associate Director,

Harvard University

Environmental Health & Safety Department

46 Blackstone Street

Cambridge, MA. 02139

Mary_corrigan@harvard.edu