Bay Area is California’s COVID hotspot as cases rise again
California’s COVID case rates have nearly tripled since late March, and in a newly emerging dynamic, Bay Area counties are seeing case rates higher than the state’s.
“It’s the first time we’ve seen that,” said John Swartzberg, professor emeritus of infectious disease and vaccinology with the University of CaliforniaBerkeley. “It’s always been the other way around.”
Case rates here are some of the worst in the state right now. San Francisco’s case rate is more than double the state’s case rate, with a 7-day average of more than 30 daily cases per 100,000 residents. Data updated on May 6 shows every Bay Area county has a case rate higher than the state’s, as new highly contagious variants continue to spread.
The rising infections have only led to a slight 12% increase in hospitalizations, from a low of 1,224 hospitalized COVID patients on April 25 to over 1,369 on May 5. Cases are still just one tenth of what they were during the dramatic peak in January 2022, from the deadly omicron surge.
But with most restrictions and mask mandates a thing of the past, Bay Area counties are seeing more than three times as many positive cases as they were about six weeks ago, after the winter omicron surge had abated.
Case rates in the state dropped below 10 daily cases per 100,000 residents for a few weeks, from March 3 through April 19, once the threshold for California’s purple tier of COVID restrictions.
The situation in the Bay Area and California follows a rise in cases across much of the country. Cases nationwide are up 170% to levels not seen since February, according to the Centers for Disease Control and Prevention. Hospitalizations are up 16% in a week to levels not seen since March. And deaths have started to inch up after steady declines since February.
Transmission levels are high all along the West Coast, throughout the Northeast and Great Lakes and southern portions of Texas and Florida, CDC data show. And community levels, meant to indicate the virus’ impact on regional health care, are at the yellow medium level in the Bay Area and 10% of the country as a whole. That’s a level where the CDC says those at high risk should consider wearing a mask. Much of the Northeast is at the high level where the CDC recommends wearing masks in public indoors.
San Francisco was the first county in the region to experience an increase in cases, as early as midMarch, followed by Santa Clara, San Mateo and then the others. And all of those counties have had case rates higher than the state’s for several weeks, despite historically having lower case rates than the rest of the state for almost the entire pandemic. The case rates in Los Angeles is currently slightly above the state’s case rate, but has yet to hit 20.
But case rates undercount how much virus is actually spreading, according to experts, especially now.
“There’s a real big disconnect between cases reported and the actual number of cases,” said Swartzberg. He pointed to research showing that a smaller proportion of cases are being detected and counted now than in other recent waves, meaning the rise in cases is even worse than the current data indicates.
That’s because more people are using at-home rapid tests that don’t get counted like PCR tests performed at labs. Waning vaccine effectiveness and natural immunity are likely contributing to the new spike in cases, as well.
Dr. George Rutherford, an infectious disease specialist at UC-San Francisco, pinned the rising cases on a combination of factors.
The highly transmissible omicron variant that drove a massive wave of infections over the winter, BA.1, has spawned even more contagious cousins, known as BA.2, now 62% of cases nationally, and BA.2.12.1, now 37%, according to the Centers for Disease Control and Prevention.
“For those who were naturally infected in December or January, that immunity is starting to wane about now,” Rutherford said. “Prior infection with the regular BA.1 strain doesn’t provide nearly the protection from BA.2.12.1.”
And although the Bay Area is among the most highly vaccinated regions of the country, the shots’ protection against infection also has slipped, though they still protect against severe disease. Without a booster shot, their protection against infection isn’t so good now.
“The vaccines were great for preventing severe disease and preventing death, but their ability to prevent infection wanes over time,” Rutherford said, adding those who are do should get a booster.
Along with waning immunity and vaccine effectiveness against infection, indoor face mask requirements to check the virus’ spread have vanished from the public sphere. While most mask orders lifted in March, last month, federal officials dropped mask requirements for public transportation including air travel, commuter trains, buses and ride hailing services like Uber.
“People have stopped wearing masks and are risktaking,” Rutherford said.
While severe illness and hospitalizations haven’t risen as much as infections, Rutherford said it’s no reason to be complacent about the virus. Even a mild infection can upend your life for a week or so of quarantining and isolation due to rules to prevent the virus’ spread at work and school. But there’s also the risk of developing so-called long COVID, a lingering of symptoms that doctors still don’t fully understand.