Top UCSF doctor says he's masking up again

One of the Bay Area's top COVID experts said he's starting to mask up again.

Dr. Robert Wachter, chair of the UCSF Department of Medicine, said the asymptomatic testing rate is a good metric for how widespread COVID is in the Bay Area.

And he said it's tripled in the last few weeks in San Francisco, which means there could be as many as 1 in 30 people positive for COVID without showing symptoms.

Wachter said he had been less careful when it came to masking in places like restaurants, but now, he will be back to wearing N95's in crowded indoor spaces.

His personal decision comes as the Centers for Disease and Control is renewing a recommendation that people wear masks on public transit, despite a court order in Florida that struck it down.

The CDC wants the public to wear a mask on planes and on trains because of an increase is positive cases. 

Last week, BART's board of directors mandated that riders and employees must wear masks on trains and at station platforms until at least July 18.