Bay Area may be seeing 'early signs of flattening,' but it's too early to know for sure, experts say

A man wears a mask while walking his dog in front of Lake Merritt in Oakland on March 26. A man wears a mask while walking his dog in front of Lake Merritt in Oakland on March 26. Photo: Jeff Chiu/Associated Press Photo: Jeff Chiu/Associated Press Image 1 of / 49 Caption Close Bay Area may be seeing 'early signs of flattening,' but it's too early to know for sure, experts say 1 / 49 Back to Gallery

For more coverage, visit our complete coronavirus section here.

While it's still too early to say exactly how the coronavirus epidemic will unfold in the San Francisco Bay Area in coming weeks and months, there's a growing consensus among experts that early action and social distancing may reduce the severity of the pandemic's peak. Whether or not this will be the case, though, experts agree residents must continue to follow shelter-in-place orders with strict vigilance.

Looking at the rise in Bay Area cases in the past two months, UCSF epidemiologist Dr. George Rutherford said, "Its not an exponential rise by any stretch of the imagination compared to New York City. I think one could interpret it as maybe being very early signs of 'flattening the curve.'"

Rutherford is referring to the phrase "flatten the curve" that experts frequently use when talking about the coronavirus crisis gripping the globe. The "curve" in question is the bell curve of the epidemic, and as the virus infects more people, the graph starts to climb. In a worst-case scenario, it's an exponential climb, infecting a significant portion of the population. By limiting exposure to others — a practice known as "social distancing" — epidemiologists believe the curve could be meaningfully flattened.

Dr. Robert Wachter, the chair of UCSF's Department of Medicine, agrees the Bay Area curve is flattening.

"There’s no question that we have had a far more benign course so far than what they’re seeing in New York," Wachter said.

He pointed out that in mid-March, New York City and San Francisco had about the same number of cases, 20 or 30. As of Tuesday morning, New York City had 40,900 cases and San Francisco 397, according to Johns Hopkins University. New York City has 932 deaths and San Francisco six.

What's more, UCSF has on average had about 12 to 15 coronavirus patients at its hospital in recent days, while similar hospitals in New York are seeing hundreds of patients. "Many of our patients are suspected COVID and a decent number are sick, but numbers are not increasing dramatically and across the Bay overall patient volumes are down," said Dr. Maria Raven, a UCSF chief of emergency medicine. "But still probably too early to tell."

Health experts have been making educated guests to explain the big difference in the number of cases, and believe several factors are at play, including urban density (New York is more dense than California), differences in mass transit (New Yorkers are more likely to be packed on subways than Californians) and access to testing (New York has tested more of its residents than California).

But California's slightly earlier moves by authorities to enact social distancing policies — and New York's later implementation of extreme measures — may be one of the key reasons for the discrepancy in cases. Bay Area counties began issuing shelter-in-place orders on March 16, and California Governor Gavin Newsom implemented a mandate for the entire state on March 19. New York's order came about a week later.

"Our curve is far flatter than many other parts of the country," Wachter said. "There’s some reluctance to talk about it too much because it feels like declaring victory and if you do that, you can do the wrong thing. Things can get out of hand really quickly. We're doing the right thing now and saving lives and we have to keep it up."

San Francisco is on average seeing about 20 to 30 new cases a day. If people were allowed to move freely around the city, the increase in cases would go up exponentially.

Wachter said if the region never sees an explosive surge of cases, with hospitals overwhelmed and equipment supplies stretched, the Bay Area could experience a less dramatic but more prolonged epidemic. "It does mean the virus could linger around here long than it would otherwise," he said. "But it also means we’ll experience massively fewer cases and fewer deaths. That's a small price to pay."

SFGATE Senior Digital Editor Katie Dowd contributed to this story.

MORE CORONAVIRUS COVERAGE:

Sign up for 'The Daily' newsletter for the latest on coronavirus here.

Amy Graff is a digital editor for SFGATE. Email: agraff@sfgate.com.