California’s COVID-19 case rate jumps again as new subvariants spread throughout state

COVID-19 case rates grew significantly across the state last week, continuing a steady rise in infections that began in late April.

The California Department of Public Health on Tuesday reported the statewide case rate at 41.1 cases per 100,000 residents. The rate marks a 34.8% increase compared to one week earlier.

The state also reported a 9.1% seven-day positivity rate, the highest since Feb. 4. The positivity rate marks an increase from 7.6% the previous week, and 6.7% the week before.

State health officials reported 2,762 patients hospitalized with confirmed COVID-19, up 7% from a week prior.

Sacramento County has seen similar rises in nearly all metrics related to the virus, including a 29.4% increase in its weekly case rate. The county’s positivity rate stands at 13.7%, up .4% in the last week.

Positivity rates for other counties in the Sacramento region have fluctuated. Yuba County has the sixth-highest positivity rate of California’s 58 counties, at 14.5%, up from 12.9% last week. The positivity rate in Yolo County also rose to 5.4% from 4.5% the previous week. But positivity rates in El Dorado and Placer counties have dropped, despite significant rises in case rates.

The CDC issues community level designations at the county level at the end of each week. Sacramento County has remained in the “high” designation for the last two weeks. Thirteen California counties received the designation at the end of last week, and the rise in cases statewide may lead more counties to enter the “high” level at the end of this week.

The CDC recommends indoor masking for all areas in the “high” level of spread. So far, only Alameda County has reintroduced an indoor mask mandate, with local officials citing growing hospitalization rates.

BA.4 and BA.5 subvariants continue to grow

The BA.4 and BA.5 subvariants continue to rise nationally and in the California region.

The omicron subvariants first gained traction in Europe and South Africa, and have been declared variants of concern by the CDC. A report by the European Centre for Disease Prevention and Control released Monday said that the “growth advantage” of the two variants suggests that they will soon dominate other omicron subvariants, “probably resulting in an increase in COVID-19 cases in coming weeks.”

Within the United States, data released by the Center for Disease Control for the week ending in June 11 indicates that the new variants now make up 21.6% of all cases nationally. 8.3% were BA.4 and 13.3% were BA.5.

This total marks a 66% increase from one week earlier, when only 13% of cases nationwide were BA.4 or BA.5.

The BA.2.12.1 omicron subvariant still remains the dominant variant nationwide, at 64.2% of all cases. The original BA.1 omicron subvariant has disappeared.

In the CDC region containing California, Arizona, Nevada, Hawaii and island territories, the BA.4 and BA.5 variants are slightly less prevalent, making up 21.1% of all cases. This is an increase from 13.1% a week earlier and from 7.5% the week before.

BA.2.12.1 makes up 60.4% of cases in the region, and BA.2 makes up 18.4%.

The new variants have been identified in the Sacramento area as well as the Bay Area. Healthy Davis Together, one of the only Northern California COVID-19 surveillance programs that tests for BA.4 and BA.5, last reported the two subvariants making up 12.9% of Yolo cases that were sequenced during the week ending June 4, compared to 6% the week of May 28 and 3.1% the week of May 21.

Sacramento-area numbers by county

Sacramento County’s latest case rate — reflecting the week ending in June 6 — is 44 per 100,000 residents, state health officials said in Tuesday’s update. This marks a 29.4% increase from the case rate one week earlier, and a 14.8% increase from the most recent metric released Friday.

Hospitals in Sacramento County were treating 210 COVID-19 patients on Monday, state data shows, up by 24.3% from 169 one week earlier. The intensive care unit total was 20, the same as last week. ICU bed availability remains high.

Placer County’s latest case rate is 29.4 per 100,000 residents, a 13.5% increase from one week earlier.

Hospitals in Placer County were treating 86 virus patients Monday, up from 76 one week earlier. The ICU total dropped to seven from 11.

Yolo County’s latest case rate is 39.5 per 100,000 residents, a 30% increase from one week earlier. The county has one of the lowest positivity rates in the state at 5.4%. Only Los Angeles and Lassen County have lower rates.

Hospitals in Yolo County were treating four virus patients Monday, up from two a week earlier. The ICU total remained at zero.

El Dorado County’s latest case rate is 28.9 per 100,000 residents, a 24.6% increase from one week earlier.

Hospitals in El Dorado County were treating eight virus patients Monday, down from 10 a week earlier. The ICU total dropped to one from five.

This story was originally published June 14, 2022 at 2:15 PM with the headline "California’s COVID-19 case rate jumps again as new subvariants spread throughout state."