The SARS-CoV-2 transmission riddle - Part 3

Binary PCR positivity is a meaningless test result on its own

While immersed in reviewing studies, we soon realised that a “case” meant different things depending on where you looked.  In September 2020, we documented these differences. We were confused then, as much as now, by one central question: when is Covid-19 Covid-19?

Most if not all confirmed cases are based on a positive polymerase chain reaction (PCR) te…