Phil Jones yes the RT PCR is a very sensitive test than check for anything. If the cycles are magnified enough it would show us all to have everything. That's why the WHO don't recommend on its own as a means of diagnosis. The common test used for flu is “rapid influenza diagnostic tests" (RIDTs).
RT just means real time or Reverse transcription. PCR on its own takes longer to get the results. It shouldn't make a difference however you won't be getting the results of a PCR within the required 72 hours. What they won't accept is a lateral flow test or antigen test. Both are actually useless in detecting true infection.
