[blueash]

Originally Posted by graciegirl

Eleven patients does not make for a large study to prove or disprove anything and I am sure that is the point you are making.

We all are clutching at straws. Hoping for a vaccine sooner than predicted. Stay safe, Doctor. I like to debate you on politics but highly respect your medical experience and knowledge.

Exactly correct. This is a small study that attempted to replicate a very specific finding from another study.. That HCQ and Zithromax combined was 100% effective in making patients culture/PCR negative. This study failed to replicate that finding and in fact failed to show any benefit at reducing that specific goal, making the patient virus negative.

And as you are a reliable reader I'll digress here to explain culture vs. PCR. In the cultures done in the French studies, a sample is taken then incubated with live cells. If there is virus present those cells are disrupted and this alteration is visually confirmed by microscope. In pcr testing the presence of the RNA [like DNA] known to exist in the virus is measured. PCR is what the labs are using in large scale testing. This distinction is potentially important. A viral culture proves that the virus is still active and capable of attacking cells. While a virus is not "alive" that is a reasonable analogy. On the other hand, a positive PCR could occur if inactive viral particles are present which still have RNA intact but are no longer capable of causing disease. There are animal and human studies showing that the PCR stays positive after the culture becomes negative in other corona virus diseases. You can read about them in the Lancet

In a ferret model of H1N1 infection, the loss of viral culture positivity but not the absence of viral RNA coincided with the end of the infectious period. In fact, real-time reverse transcriptase PCR results remained positive 6–8 days after the loss of transmissibility. For SARS coronavirus, viral RNA is detectable in the respiratory secretions and stools of some patients after onset of illness for more than 1 month, but live virus could not be detected by culture after week 3

But because viral cultures are very difficult to do, using PCR is standard. You have certainly read reports of Covid being found in stool samples after clinical recovery. Those are AFAIK all PCR findings.