0 the number of all tests for an illness that are positive (= show that someone has the illness), expressed as a number out of a hundred: --
Expanded testing does not always reduce the percent positive when there is widespread transmission; it may reveal more people who are infected.
A low percent positive simply means that the level of coronavirus transmission, relative to the amount of testing, is low at this point in time.
The laboratory test percent positive goes down when more people tested are negative.