REDWOOD CITY (CBS SF) — With additional testing facilities coming online, San Mateo County health officials announced Wednesday they have 79 new confirmed cases of the coronavirus — the largest single day jump among county residents since the outbreak began in January.

County officials said the county’s death toll remained at 10 — 6 victims over the age of 80, 4 of them female. The new cases swelled the number of San Mateo County residents suffering from the coronavirus to 388 since the outbreak began.

While the number of new cases and deaths have been foremost in local residents minds, state leaders and health officials say they are increasingly focused on a different metric. They are using the number of people arriving at the hospital.

“The number of hospitalizations, the percentage increase of 13%, intensive care units 10%,” explained California Governor Gavin Newsom. “That is in line with some of our modeling.”

For the second day in a row on Tuesday, the governor zeroed in on those specific numbers.

“I think we want to basically look at things that we can count with some consistency,” says UC Berkeley epidemiologist Art Reingold. “One of them is deaths, and one of them is hospitalizations.”

Reingold says the test results everyone has been following only tell part of the story. When it comes to how many people are infected, the virus itself is probably a more reliable indicator. That is because the percentage of people who get really sick from it is relatively consistent.

“Everything else, numbers of people positive, are really subject to the amount of testing going on, so they’re really hard numbers to interpret,” Reingold says of the numbers. “We think that hospitalizations are a better indicator, yes.”

But the positive test results do give some evidence as to spread, and that is where there is some reason for early, cautious optimism in the Bay Area.