Fauci today: “Part of the reason for wearing face masks is to protect you from infecting you–he gestures at reporters. I had my test yesterday and it was negative.” But isn't there a substantial false negative rate on tests, leaving aside the role model reasons to wear a mask?
I saw it in passing here: https://www.livescience.com/covid19-coronavirus-tests-false-negatives.html … Uncertainty in the number seems to be very high, and it depends on the test type. But my understanding is that false positives are rare, but false negatives fairly common