COVID-19 cases in Sonoma County rising again, but pandemic experts hope for a much smaller wave

COVID-19 infections again are increasing in Sonoma County and everywhere else, leaving many local residents wondering if another pandemic surge is around the corner.

But local experts say there are some good signs that the next COVID-19 bump will be more of a wave than the kind of surges that burdened local health care systems last summer and over the winter.

“It’s not a surge, it’s what some people are calling a wave,” said Dr. Sundari Mase, the county’s health officer.

Mase said that while virus transmission rates and test positivity, the share of COVID-19 tests that result positive, are “creeping upward,” the number of coronavirus patients in intensive care has not spiked. COVID-19 deaths have remained low, she added.

John Swartzberg, an infectious disease expert at UC Berkeley, said that while COVID-19 hospitalizations have increased in the past couple of weeks, the rise is not proportional to the number of infections that are being detected.

Swartzberg said current COVID-19 vaccines — while not as good at preventing infection — are still very effective at preventing severe illness and death.

“That’s why getting a booster is still really important,” he said. “We’re still in the midst of a pandemic with SARS-CoV-2 (the virus that causes COVID-19 illness). An awful lot of people think the pandemic is over and are acting accordingly.”

Swartzberg said the current increase in cases is being fueled by “subvariants of the omicron variant that caused such havoc in December and January.”

Dr. Chad Krilich, chief medical officer for Providence Sonoma County, which runs Santa Rosa Memorial, Petaluma Valley and Healdsburg hospitals, said there’s been no “appreciable change” in the number of COVID-19 patients at Santa Rosa Memorial Hospital in the last two months.

“Today we have six patients in the hospital who are COVID-positive, two of which are in the ICU. This has been our experience on average over the last couple months,” he said.

Krilich also stressed the importance of getting vaccinated and continuing to practice pandemic-era precautions, such as hand washing, masking and social distancing.

Mase said COVID-related deaths and ICU admissions are the best markers of the severity of pandemic waves or surges. Current case rates are likely an undercount of actual virus transmission because so many people are using rapid antigen testing and the results often go unreported.

The current rate of transmission in Sonoma County is an average of 18.7 new daily cases per 100,000 people. The overall test positivity is at 6.6%.

During the lowest point of transmission this spring, around the middle of March, the difference in infection rates between vaccinated and unvaccinated residents was small. On March 16, vaccinated residents had an infection rate of 5.8 new cases per 100,000 people, while unvaccinated people had a rate of 9 cases per 100,000.

As with previous waves and surges, that gap is widening. Today the vaccinated have a transmission rate of 13.2 cases per 100,000 and the unvaccinated have a rate of 45.6 new daily cases per 100,000.

Swartzberg said the current wave is being caused by a subvariant of the omicron variant, BA.2. But he said a new descendant of omicron, BA.2.12.1 — even more transmissible than BA.2 — is now vying for dominance.

There’s still no evidence that BA.2 causes more severe illness, he said, and it’s still too early to determine the virulence of BA.2.12.1.

For Mase, the best way to navigate the uncertainty of the next few weeks is with caution and vigilance. She said masking indoors is still highly recommended, and those who have not yet received a booster should do so.

“It’s still a pandemic because the virus is circulating worldwide,” Mase said.

You can reach Staff Writer Martin Espinoza at 707-521-5213 or martin.espinoza@pressdemocrat.com. On Twitter @pressreno.