In addition to the masking advice, health officials have also advised vulnerable residents to start planning now for how they will access treatments – including the antiviral Paxlovid – if they test positive. And they reminded people to resume other precautions, like limiting large gatherings indoors or even moving activities outside.

As of Thursday, there were 397 people with COVID in Bay Area hospitals, marking a 70% increase from a month ago, according to state data analyzed by The Chronicle. San Francisco reported the largest increase, with 67 people hospitalized with COVID, up from 24 on April 12. Contra Costa and Santa Clara counties are seeing similar trends as new cases driven by the increase in the highly transmissible BA.2 omicron subvariant in the region.

The Bay Area reported about 30 daily new cases per 100,000 residents on Friday, which is significantly higher than the statewide average of 19 per 100,000.

The disturbing trends have prompted health workers in the Greater Bay Area – Alameda, Contra Costa, Marin, Monterey, Napa, San Benito, San Francisco, San Mateo, Santa Clara, Santa Cruz and Sonoma counties, as well as the City of Berkeley – to issue their joint statement asking residents to take personal precautions to avoid the virus. They noted that actual case rates are likely higher than those reported due to the widespread use of home testing.

“With the increase in COVID-19 cases in San Francisco, people are at high risk of contracting COVID-19 right now, and we urge people to take personal protections against the virus,” said Dr. San Francisco health officer Susan Philip. , in a report. “People at high risk of severe illness or who are in close contact with someone at high risk should be especially vigilant as we navigate this current wave of cases.”

In an interview, Philip added that looking at COVID rates now is like looking at terrible weather. “It’s not great having to tell people there’s a hike,” she said. “It’s time to think about the protection options available, but it’s good that we have those options.”

In San Francisco, the rate of positive coronavirus tests has reached 10.3% – more than double California’s overall rate of 4.4%, and well above the 5% level that infectious disease experts consider as acceptable to control the spread of the virus.

Philip and other health workers said it’s unclear why the Bay Area is seeing significantly higher case rates than the rest of the state, though they have some theories.

It is possible that with our very high vaccination levels, fewer people here have been infected before than elsewhere, so there is a greater chance of the virus spreading. Another guess is that new, more infectious variants took hold in the Bay Area before other regions. The Bay Area may also test more than other counties.

“I’m less worried (why the Bay Area is higher) and more encouraged that the level of serious illness isn’t being seen here,” Philip said.

California surpassed 90,000 confirmed COVID deaths since the pandemic began on Friday. That’s more than any other state, but California is the most populous in the country and its death rate per 100,000 people remains among the lowest in the country. The state has reported about 40 deaths a day, down from 38 earlier this week.

Alameda and Sonoma County joined San Francisco, Santa Clara, Marin and San Mateo counties in the “yellow” tier of the US Centers for Disease Control and Prevention’s COVID-19 community prevalence levels this week, reporting that more than 200 cases were reported in the last week per 100,000 population. The designation signals an average level of coronavirus present in each county, with the CDC recommending those at high risk use face masks.

Contra Costa, Solano and Napa counties, alongside almost all other counties in California, remained in the “low” community level, with fewer than 200 cases per 100,000 population.

On the CDC’s separate “community transmission” rating, based on the number of cases per 100,000 and positive test rates, all nine Bay Area counties, as well as all of coastal California, are classified as “high », the worst level.

Marin County officials said earlier this week that case rates had tripled since the first week of April, when BA.2 became the dominant strain in the county. Congregate settings such as schools, long-term care facilities and correctional facilities have all reported outbreaks, with sewage samples confirming an increase in the presence of the virus in the area.

“Each variant is different,” Marin County Public Health Officer Dr. Matt Willis said in a statement. “We’re learning in real time about this new strain and what it does and doesn’t do. It’s very good at infecting people, including those who are vaccinated. But it does not send vaccinated people to the hospital.

The health department recommends residents avoid non-essential indoor gatherings as long as transmission levels remain high and wear a properly fitted KN95 or N95 mask in any public indoor setting.

“The virus is changing and our approach must also change,” said Dr Willis. “It’s increasingly likely that most of us will have a date with COVID if we haven’t already. The key is to get vaccinated and boosted before that happens so we don’t not get seriously ill, and we need to work together to prevent infections among the most vulnerable and ensure they have access to treatment.

Deaths, a lagging indicator of pandemic trends, have dropped dramatically in the Bay Area since the winter omicron surge due to high immunity levels and increased access to treatments such as the antiviral pill Paxlovid. The Pfizer drug can stop mild COVID symptoms before they become severe and is now available at most pharmacies.

“The tools available now, especially being fully vaccinated and boosted, are having impacts,” said UCSF chief medical officer Dr. Bob Wachter. “It means we no longer fear dying from this infection, which is very different from two years ago.”

Aidin Vaziri (he/him) and Erin Allday are staff writers for the San Francisco Chronicle. Email: avaziri@sfcrhronicle.com and eallday@sfcrhronicle.com. Twitter: @SFMusic and @erinallday