Highlights

A new study analyzed genes in nasal swabs from asymptomatic people who tested positive for SARS-CoV-2.
The study found a cluster of people who worked together in a lab that focuses on plasmids.
Plasmids are tiny bits of DNA commonly used to study the proteins produced by viruses.
The analysis attributed the positive tests to the plasmid DNA, not the virus RNA.
The new study shows the importance of considering occupation in diagnostic exams.