Coronavirus infections have continued to climb steadily in California since early April, and although the curve of new cases remains less steep than the winter surge of the omicron variant, the growing spread of two contagious subvariants still raises concerns about a new wave of virus cases.
the On Friday, the California Department of Public Health reported the statewide daily COVID-19 case rate at 14 per 100,000 population, an increase of 27% last week and 71% over the past two weeks.
Test positivity jumped 2.8% to 3.9% last week for California’s highest reading since Feb. 18, when the state remained on the downward slope of the omicron push.
California’s case rate fell to 5.2 per 100,000 and positivity to 1.2% in mid-March.
Hospitals across the state were treating 1,112 patients with COVID-19 confirmed Thursday, after hitting a low of 950 on April 25, for a 17% jump in the past 10 days. Patients infected with the virus in intensive care units during the same window increased by 50%, from 112 to 168, the CDPH reported on Friday.
Some of the highest transmission rates in the state are now being recorded in the Bay Area. San Francisco now has the highest daily case rate at 32 per 100,000, a 66% increase from two weeks earlier.
The next four counties by case rate in Friday’s update were San Mateo at 28 per 100,000, Santa Cruz at 28 per 100,000, Santa Clara at 25 per 100,000 and Alameda at 22 per 100,000.
San Francisco also has the fourth highest positivity rate in the state at 8.6%, behind Imperial County alone at 10.3% and the state’s two least populated counties, Alpine and Sierra, both at 14.3%. Marin and Sonoma counties each recorded 7.8% positivity, double the state average.
More concerning, the number of patients hospitalized with COVID-19 in San Francisco has more than doubled in the past 10 days, from 26 to 55, according to state health figures updated Friday. San Francisco’s ICU total rose from three to 10.
The U.S. Centers for Disease Control and Prevention, in an update this week to its three-tier national map of “community levels” for COVID-19, showed Marin, San Francisco, San Mateo, Santa Clara and Santa Cruz in the “medium level” of coronavirus activity. The other 53 counties in California are at the “low” level.
Virus metrics vary across Sacramento-area counties, currently better than most Bay Area counties, but slightly worse than the state average.
Sacramento County hospitals reported 67 patients infected with the virus on Thursday, up from 56 a week earlier, with intensive care numbers rising to 11 from eight.
Sacramento and Bay Area high schools report outbreaks or clusters of COVID-19 cases, some of them coming weeks after many schools staged the prom or similar dance events and a few weeks after spring break.
“We are seeing an increase in cases in general and we have seen an increase in cases and outbreaks reported by schools in recent weeks,” Sacramento County Health Unit spokeswoman Samantha Mott said Thursday in a statement. press release sent by e-mail.
Latest news on omicron contagious subvariants
A pair of highly transmissible omicron subvariants, called BA.2 and BA.2.12.1, now account for the vast majority of cases in the United States, with the prevalence of the latter gradually increasing. Both variants are likely responsible for much of the rise in transmission rates in California.
BA.2.12.1, the more contagious of the two, accounted for about 37% of cases nationwide for the week of April 24 to April 30, according to a weekly update Tuesday from the CDC, up from 27% the previous week. BA.2 dropped from 70% to 62%, suggesting that BA.2.12.1 may soon surpass it.
For the CDC region which includes California, Arizona, Nevada, Hawaii and the Pacific territories, BA.2.12.1 went from 12% to 18% last week, while BA.2 went from 85% at 81%.
Health officials have estimated that BA.2 is about 40% more transmissible than the original omicron variant, BA.1; and BA.2.12.1 would be about 25% more contagious than BA.2.
BA.2.12.1 Spread at UC Davis
Yolo County health officials last week, in a joint press release with the Healthy Davis Together testing initiativesaid BA.2.12.1 “now accounts for nearly half of on-campus cases” at UC Davis after it was first detected there in late March.
“The data shows that COVID-19 is spreading in Yolo County, especially in Davis. Yolo residents are encouraged to take extra precautions to guard against infection,” Yolo County Health Officer Dr. Aimee Sisson said in a prepared statement.
“I highly recommend masking up indoors with a high-quality mask and getting tested if you have symptoms, have known exposure, or have recently attended a large gathering like Picnic Day,” which was held on April 23, Sisson said. “If you’re eligible for a booster now’s a good time to get it, don’t wait.”
It’s still unclear exactly how much immune protection Californians can maintain against the huge wave of infections during the omicron surge, which pushed the case rate above 300 per 100,000 and positivity above. by 22% in early January, as experts study the ability of new subvariants to evade prior immunity.
Sacramento Area Numbers by County
Sacramento County’s latest case rate is 9.9 per 100,000 residents, state health officials said in Friday’s update, a 26% increase from the previous week. .
CDPH reported Sacramento’s test positivity rate at 4.5% on Friday, up from 3.8% a week earlier.
Sacramento County hospitals were treating 67 patients infected with the virus as of Thursday, state data showed, up from 56 a week earlier. The total for intensive care has been reduced from eight to 11.
Placer County’s latest case rate is 8.1 per 100,000 population, a 33% increase from the previous week.
CDPH reported a Placer test positivity rate of 5.3%, up from 4.1% last week.
Placer County hospitals were treating 23 patients infected with the virus on Thursday, up from 26 a week earlier. The intensive care total remained at four.
Yolo County’s latest case rate is 13.6 per 100,000 population, a 30% increase from the previous week.
The CDPH reported the Yolo test positivity rate at 2.2%, up from 1.6% last week.
Yolo County hospitals were treating two patients with the virus on Thursday, up from three a week earlier. ICU total increased from one to zero.
El Dorado County’s latest case rate is 7.7 per 100,000 population, state health officials said in a Tuesday update, a 27% increase from the previous previous week.
The CDPH reported an El Dorado test positivity rate of 5.3%, up from 5.2% last week.
El Dorado County hospitals were treating two patients infected with the virus on Thursday, up from one the previous week. ICU total increased from one to zero.
Sutter County’s latest case rate is 6.8 per 100,000 population and Yuba County’s is 5.0 per 100,000, state health officials reported Friday. Sutter’s case rate rose 115% while Yuba’s fell 20%.
The CDPH reported Sutter at 4% test positivity, down from 4.5% last week. Yuba’s positivity was 4.6%, down from 3.2%.
The only hospital in Yuba County, which serves the Yuba-Sutter bi-county area, was treating four patients with the virus on Thursday, up from two a week earlier. The total ICU held to a patient.
The CDC classifies all six counties in the Sacramento area as being at the “low” level of COVID-19 activity.
This story was originally published May 6, 2022 10:47 a.m.