COVID-19 spread and hospital totals on the rise in California as new variant arrives in US

The COVID-19 test positivity rate and the number of hospital patients infected with the disease has been on a steady increase this summer in California, recent state health data show.

The increase in coronavirus activity comes as federal officials recently detected a new subvariant in the United States, with local health experts again warning those most at risk to protect themselves from the infectious disease.

The seven-day COVID-19 test positivity rate in California is at 13.2%, based on state health data updated Thursday, showing figures through Monday. That’s an increase by 2% from the week before and a 6.5% jump from July 24. California’s seven-day positivity rate has been climbing since May 5, when it was at 3.4%, and is now at its highest point since July 2022.

There were 1,438 total hospital patients with COVID-19 in California as of Aug. 19, according to the most recent state data. That’s 194 more than the previous week, according to Thursday’s weekly update from the California Department of Public Health. On July 19, there were 873 COVID-19 patients in hospitals statewide.

The U.S. Center for Disease Control and Prevention on Wednesday issued a risk assessment summary explaining what is known about the new COVID-19 virus subvariant BA.2.86. The risk assessment was issued after at least two cases of a new variant were identified in the United States, Newsweek reported. The variant also has been detected in U.S. wastewater samples.

CDC officials said all viruses, including SARS-CoV-2, the virus that causes COVID-19, change over time, and these changes can affect how contagious a virus is, how well it responds to treatment and how severely it affects people.

Existing tests used to detect and medications used to treat COVID-19 appear to be effective with this variant. But CDC officials warned BA.2.86 may be more capable of causing infection in people who have previously had COVID-19 or who have been vaccinated. There is no evidence that this variant is causing more severe illness, but that could change as additional scientific data are developed.

Health officials point to summer travel, people spending more time near each other indoors due to hot weather and new viral variants as likely causes for the increase.

Yolo County officials last week alerted residents of an increase in COVID-19 activity locally as similar increases are being observed across California. Rising levels of the virus have been detected in Yolo County wastewater. Officials said wastewater levels of SARS-CoV-2 in Davis are at their highest since last winter’s surge, and rising levels also have been detected at monitoring sites in West Sacramento, Woodland and Esparto.

Yolo County Public Health Officer Dr. Aimee Sisson emphasized the importance of vigilance and preventive measures.

“Through our wastewater monitoring program, we are seeing a significant uptick in levels of the virus that causes COVID-19, especially in Davis and West Sacramento,” Sisson said in a news release. “While the current levels are categorized as medium and not high, we are warning more vulnerable members of the community of the rising risk so they can take actions to protect themselves.”

The health officer advised Yolo County residents to consider taking precautions if they are at high risk of severe COVID-19 disease, live with people who are at high risk or simply want to avoid infection. Older adults, people with underlying health conditions and those who are immunocompromised are considered to be at high risk of the disease.

COVID-19 rising in the Sacramento region

The seven-day COVID-19 test positivity rate in Sacramento County is at 13.3%, based on state health data updated this week. That’s a 2.3% increase from last week and a 7.1% jump from July 23. Sacramento County’s seven-day positivity rate was 4% on June 28.

There were 74 total hospital patients with COVID-19 in Sacramento county as of Aug. 19, according to the most recent state data. The county had 60 COVID patients a week before, according to CDPH.

In Yolo County, the seven-day test positivity rate also climbed by 2.3% from the previous week, to 16.1% on Monday. The seven-day rate was 7.8% on July 21. There were four hospital patients with COVID-19 in the county as of Aug. 19, up from three the previous week.

In Placer County, the seven-day test positivity rate rose by 1.2% from the previous week to 14.9% this week. The county’s seven-day rate was 9.6% on July 21. There were 38 total hospital patients with COVID-19 in the county as of Aug. 19, five fewer patients than the previous week.

The seven-day test positivity rate for El Dorado County is at 19%, an increase by 6.1 percentage points from last week. The county’s rate was 10.1% on July 21. There was one hospital patient with COVID-19 in the county as of Aug. 19, 3 fewer patients than the previous week.

Tips for avoiding COVID-19

For those concerned about contracting COVID-19, Sisson recommended these preventive measures:

Stay up-to-date with COVID-19 vaccination.

Wear a mask in crowded indoor spaces.

When indoors, improve ventilation by using a high-quality filter in your HVAC and by adding a portable HEPA filter in rooms where you spend time with others.

Minimize close contact with people outside your household, especially in crowded settings.

Wash your hands regularly with soap and water for at least 20 seconds. Hand sanitizers are a convenient alternative when soap is not available.