A team of researchers has found very isolated small fragments of the Sars-CoV-2 coronavirus in the genome of human cells. This may be an explanation for false-positive tests.
The group explains in the Proceedings of the U.S. National Academy of Sciences (“PNAS”) that the genetic fragments do not pose a danger. Such fragments cannot lead to whole virus particles and also cannot trigger a new infection, as the researchers led by Rudolf Jaenisch of the Whitehead Institute for Biomedical Research in Cambridge (Massachusetts, USA) write. The discovery could be a possible explanation for why some people continue to test positive for Sars-CoV-2 on PCR testing long after their corona infection.
The study’s findings are supported by research published in the journal PLOS ONE: A group led by Ithan Peltan of the University of Utah in Salt Lake City studied patients who tested positive for the virus again with a PCR test 60 or more days after a positive corona test. In around 90 percent of cases, there was no Sars-CoV-2 infection despite a positive PCR test, i.e. there was no new infection.