Here is a quote from an article where an expert says that the measures taken to stop the spread of the current coronovirus are not up to par. What I don't understand in it is the very last phrase:
The author also argued that official numbers are “grossly underestimating” the true toll of infections.
“They have a lag time in testing people; they don’t have enough test kits; they have lines around the block, in Wuhan, of people trying to get tested,” says Garrett. “It’s wholly backed up.”
What is wholly backed up? How is it backed up and by whom? And what kind of "backing up" exactly it is?
I know of two meanings of "back up". First one is "support" and the second one is "accumulate", but it looks like here is some other meaning.