The chart above is from the Morning Consult Poll. They surveyed 2,000 registered voters in three different time periods (Feb 7-9, Feb 24-26, and March 3-5). The surveys have a margin of error of 2 points.
At the beginning of February (7th thru 9th), most people (61%) approved (at least somewhat) of the way Donald Trump was handling the possible epidemic of the Coronavirus. I think they hoped Trump would understand the seriousness of the situation and do what a president should.
Near the end of February (24th thru 26th), that approval have dropped to 56%. People were beginning to have doubts as to whether Trump was up to the task he faced.
By the first week of March (3rd thru 5th), that approval had dropped to 44%. people were beginning to understand the awful truth. Trump has not risen to the task. He has treated this crisis just like he's treated everything else. He only cares how it affects him politically (and his chances of re-election).
He has called the virus a "hoax" perpetrated by Democrats to hurt his presidency. He has labeled it as just another "flu". He has said there are plenty of tests available for anyone who wants to be testing (even though the Coronavirus committee headed by Pence has said just the opposite). He has even said the virus will magically disappear in April. And he has bragged about being a scientific expert on the issue.
In other words, his response to the possible epidemic is to lie.
I expect to see the approval of Trump's handling of the virus to fall even further in the coming days and weeks. Only a confirmed "trumpista" could overlook the incredible incompetence he has shown.