I learned this as a fact last week. We recently had to have my 94-year-old mother transported to the hospital because she was exhibiting symptoms of a stroke (slurred speech and sagging face, loss of movement in left leg and arm). But since we had read that stroke symptoms were often present in elderly COVID-19 patients, we asked the attending physician on her case whether she had been tested for COVID: no, they replied, she is not exhibiting symptoms (fever, trouble breathing, etc.). We asked again a day later to the next attending physician: same answer.

She's been home now (with her caregivers) for a little over a week, with PT and OT coming to the house. So far, she seems much better, and can even walk with a walker short distances. No sign of COVID (yet). So I hope they were right.

It does seem there is little sense in getting tested (unless, like the top WH officials you can get tested daily) unless you are exhibiting symptoms. The number of tests is limited, so they can't be used indiscriminately.