California sees COVID-19 numbers rise to start December. Is a winter surge inevitable?

As California enters its third December of the coronavirus pandemic, several key indicators of COVID-19 spread are again surging.

The statewide daily case rate increased to 13.1 per 100,000 residents, the California Department of Public Health said in a weekly update Thursday.

Test positivity spiked to 10.8%, up from 7.9% one week earlier and rising above 10% for the first time since mid-August. The positivity had dropped as low as 4.2% as recently as late October.

The previous wave, which ran from spring into summer, saw positivity climb from about 2.5% in late April to just over 16% in early July. California’s positivity is now climbing about as steeply as the beginning of that surge.

CDPH reported 3,793 COVID-positive patients in hospital beds statewide, a 36% increase from one week earlier and up 132% from the start of November.

Virus levels found in wastewater have also spiked dramatically in recent weeks, according to data collected by the Stanford-based Sewer Coronavirus Alert Network.

Recent data from the project showed most of the Bay Area and Sacramento-area wastewater sites displaying anywhere between four to eight times higher by late November than at the start of the month. Sacramento’s virus levels have roughly quadrupled in the past four weeks.

The latest surge comes as new subvariants of omicron have in recent weeks overtaken BA.5 as the dominant variant spreading in the U.S.

Sister variants BQ.1 and BQ.1.1 combined for 57% of cases nationwide, the U.S. Centers for Disease Control and Prevention said in a weekly update last Friday, up from 48% the preceding week and 38% two weeks earlier.

Health officials say there are early signs that the BQ-family variants may be able to avoid prior immune protection, leading to many reinfections.

Throughout the pandemic, COVID-19 has spread more easily during the winter months, as cold weather and end-of-year holidays drive people to gather indoors.

COVID-19 cases rising fast at California nursing homes

New confirmed COVID-19 cases in California skilled nursing facilities have more than quintupled in the past four weeks, from a seven-day average of 61 cases for the week of Nov. 1 to 311 cases for the week of Nov. 29.

Last winter’s omicron surge peaked at about 620 daily cases in skilled nursing homes, and the previous winter surge, which began before vaccines had widely rolled out, topped out at about 730 per day.

Nursing homes were hot spots for deadly COVID-19 outbreaks in the earliest months of the pandemic, but fatalities have slowed significantly since the launch of vaccines in late 2020.

According to CDPH, 88% of skilled nursing residents are now vaccinated, compared to 72% of California’s general population.

Sacramento-area numbers by county

Sacramento County’s latest case rate is 13.9 per 100,000 residents, state health officials said in Thursday’s update, a 24% increase from one week earlier.

Hospitals in Sacramento County were treating 136 patients Wednesday, state data updated Thursday show, up from 114 one week earlier. The intensive care unit total increased to 20 from 18.

Placer County’s latest case rate is 12.1 per 100,000 residents, a 9% increase from one week earlier.

Hospitals in Placer County were treating 73 virus patients Wednesday, up from 65 one week earlier. The ICU total increased to nine from six.

Yolo County’s latest case rate is 8.8 per 100,000 residents, a 6% increase from one week earlier.

Hospitals in Yolo County were treating six virus patients Wednesday, down seven a week earlier. The ICU total increased to three from two.

El Dorado County’s latest case rate is 13.3 per 100,000 residents, a 24% increase from one week earlier.

Hospitals in El Dorado County were treating 11 virus patients Wednesday, down from 12 a week earlier. The ICU total remained at zero.

Sutter County’s latest case rate is 10.3 per 100,000 residents, down 22% from last week, and Yuba County’s is 14.2 per 100,000, up 29%, state health officials reported Thursday.

The only hospital in Yuba County, which serves the Yuba-Sutter bicounty area, was treating 10 virus patients Wednesday, up from four a week earlier. The ICU total increased to one from zero.