Ruh roh (at least in SF): asymptomatic test positivity rate @ucsfhospitals now 5% (was ~2% last month). While not a perfect sample, implies that ~1 in 20 people in SF who feels well would test pos. for Covid. In a crowd of 10: 40% odds ≥ one is pos. Airplane w/ 150: 99.9% odds. pic.twitter.com/EqhLEJRT5W

— Bob Wachter (@Bob_Wachter) December 2, 2022