Before Christmas In Sonoma County, as many as 680 per 100,000 residents were getting tested each day. That’s about 3,400 daily tests countywide. Testing volume dipped during the holiday season, before again increasing during the first week of January. County officials this week reported the daily testing rate had dropped to about 490 tests, only slightly above the state’s median testing rate of 425 daily tests per 100,000 residents.
As part of the statewide pandemic reopening process, counties receive an adjustment based on local testing volume relative to the state median testing rate. If the local testing rate is greater than the state median, the county’s daily virus case rate — a key measure of COVID-19 transmission — is adjusted downward to account for the greater number of new infections being found.
The state assesses all counties’ virus transmission benchmarks every Tuesday.
Last week, Sonoma County’s testing volume dipped below the state median, so the county’s daily case rate was adjusted upward from 20.8 to 21.2 per 100,000 residents. This week, with a testing rate barely surpassing the state median, the county’s daily case rate was adjusted from 15.3 to 13.8 daily cases per 100,000 people.
The county needs to push that case, or daily rate of new virus infections, down to 7 or less per 100,000 residents, in order to qualify to advance under the state’s reopening plan and lift more limits on most businesses. For example, the county’s restaurant sector remains restricted to outdoor dining and takeout. During the recent winter surge, only takeout service was permitted.
“Testing can help detect COVID cases early, and stop possible outbreaks,” Mase said. “And it also will help us reopen our economy.”
Identifying virus mutations
As new coronavirus variants, both foreign and homegrown, begin to emerge, public health experts underscore the importance of testing to spot them.
Dr. John Swartzberg, a UC Berkeley infectious disease expert, said that without adequate testing done, it’s difficult to track the trajectory of the virus. But also, he said, insufficient testing cripples public health officials’ ability to judge the role coronavirus variants are playing, and will be playing, in the pandemic.
“Without testing, we’re blind,” Swartzberg said.
D’Arcy Richardson, Sonoma County’s director of nursing for COVID-19 response, agreed. Testing is essential for tracking COVID-19 mutations, she said, some of which could make the virus more transmissible.
“If we don’t have people getting tested, then we can’t do that genotyping to look for those new strains from South Africa, from the UK, from Brazil,” Richardson said. “It’s really important for us to know what’s happening to be able to mitigate and stop that transmission as quickly as possible when we start to see those strains … that could make these wonderful vaccination efforts less effective.”
Fewer tests at hospitals
County public health data show significant declines in testing conducted at the local public health lab, the county’s three large hospitals and at state-contracted OptumServe public testing sites.
For example, Kaiser Permanente went from doing more than 5,420 coronavirus tests during first full week of January, to 2,871 during the first week of February. Public health lab testing plunged from a high of nearly 5,000 tests during the week starting Dec. 6, 2020, to 2,820 in the first week of February.
Locally, OptumServe, which reached a high of nearly 5,000 tests during the first week of January, has dropped to 2,650 tests during the first week of this month. Also, testing at local health clinics has declined somewhat during that period, according to county public health data.
Providence St. Joseph Health, which runs Santa Rosa Memorial, Petaluma Valley and Healdsburg hospitals, went from 1,128 weekly virus tests to 819, during that same monthly stretch.
Dr. Chad Krilich, Providence St. Joseph Health’s chief medical officer, said the COVID-19 tests included those administered in emergency rooms, urgent care centers or in the hospitals. The declines, he said, could be caused by an actual decrease in coronavirus transmission, or possibly people’s lack of interest to be tested.
“Ultimately, my concern is that we don’t forget what it is that we need to do in order to see us through this phase of the pandemic,” Krilich said, citing virus tests as a critical item.
You can reach Staff Writer Martin Espinoza at 707-521-5213 or martin.espinoza@pressdemocrat.com. On Twitter @pressreno.