@b05df304 I am not sure I can derive the exact meaning of transient in this context. I assume you mean that it isn't persistent, e.g. keeps replicating so maintains threshold level presence, but instead it disappears over some (unspecified, possibly unknown and/or deviating per person) amount of time.

(I know I am making much more of your answer, but I am trying to put it in words in the way I place it into my limited understanding.) 

 @2dfc6694 TRANSIENT means existing for a short time...as in, the RNA will eventually be gone.