COVID-19 is waning in Sonoma County, but wildfire smoke could aggravate symptoms for those who still get sick

Sonoma County’s local pandemic outlook continues to improve, with infection rates dropping below the state threshold that once indicated “widespread transmission.”

But don’t put those face masks away just yet.

Local health experts say the start of wildfire season brings all-too familiar smoky skies, which could make viral illness worse. What’s more, health officials still strongly recommend their use indoors.

“We don't know if smoke has an impact on transmission, but we do know that smoke does have an impact on developing a symptomatic illness, even severe symptomatic illness,” said Dr. Gary Green, an infectious disease specialist with Sutter Health.

Green said smoke contains different chemicals that damage respiratory epithelium, tiny hair-like structures that are part of the lining of the respiratory tract and protect the body’s airways.

“When you damage the respiratory epithelium, you don't allow the body its first line of defense — innate immunity — to push back against a respiratory virus, Green said. “Now, your respiratory epithelium, your respiratory lining, has to deal with two things at once … the inflammatory and toxic damage of smoke and then the infectious damage of a pathogen at the same time.”

Similar to smoking

Dr. Sundari Mase, the county’s health officer, said that while COVID-19 transmission does appear to be waning, it’s still a good idea to wear a mask, especially when air quality dips to unhealthy levels. Mase said those who smoke tobacco are more prone to respiratory illnesses because smoke damages the cilia that line the respiratory tract.

“Those little hairs, little cilia, are very important to get rid of pathogens from the respiratory tract, because they're constantly moving things out, basically,” she said.

Mase said smokers tend to get pneumonia and bronchitis because their cilia has been damaged by smoke. She said it stands to reason that people exposed to other particulate matter, such as wildfire smoke, could also have worse outcomes of respiratory illness. “Certainly, asthma is much worse, (chronic obstructive pulmonary disease) can be exacerbated,” she said.

Moving in the right direction

Sonoma County is seeing 9.8 new daily cases per 100,000 residents. Anything under 10 new cases per 100,000 was considered “substantial transmission,” under previous benchmarks.

Under new conventions issued in the spring by the Centers for Disease Control and Prevention, COVID-19 transmission is rated “medium” in Sonoma County. Mase said unvaccinated residents are seeing higher rates of transmission.

“We still have about three times the number of cases in unvaccinated (residents) compared to vaccinated individuals, in terms of rate,” Mase said. “Luckily though, things are going in the right direction and I'm happy for that. Our test positivity is 7.2% overall. That's the lowest it has been in a very long time. So I think we're going in the right direction.”

Mase said wastewater surveillance for COVID-19 is “pretty stable” in Santa Rosa and has actually declined in Petaluma.

Green, the Sutter infectious disease specialist, said current testing data is likely not as reliable today as it was during the early years of the pandemic. Many people are testing at home and those tests are not always reported to state and local health officials, he said.

But Green said Sutter is seeing fewer COVID-19 patients.

“Our rolling average for ER visits and outpatient visits, our seven-day rolling average, is going down, which is really good,” he said.

Green also pointed out as good news that there have been no recent reports of another dominant variant surfacing since the omicron subvariants.

“I think that shows us that now the virus is settling into the human host and it's becoming endemic,” Green said. “It's really in its endemic phase.”

Green said it’s possible that while we may continue to see subvariants of the omicron strain, wholly new variants may not appear this year or next year.

That will allow scientists to “dial in the vaccine,” he said, adding that the new updated COVID-19 vaccine booster will be “be super helpful this wintertime.”

On Monday, Sonoma County health officials reported two COVID-19 deaths, one from January that was only recently determined to be pandemic related. The county’s pandemic death toll now stands at 514.

The two deaths include an unvaccinated man between age 70 and 80 who died Jan. 1, after being hospitalized. The other was an unvaccinated woman between 50 and 60 who died Aug. 4. Both had underlying health conditions.

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