Sonoma County’s emergency restrictions suppressed spread of the coronavirus

Sonoma County’s strict public health emergency restrictions appear to have squashed a much-feared surge of COVID-19 cases, allowing the county to slowly begin reopening the community while continuing aggressive tracking of infected patients and expanded testing still weeks from full implementation.

That was the key finding of the second batch of computer modeling projections of the local outbreak, prepared for the county by Imperial College London and released Tuesday. Earlier dire predictions that up to 1,500 local infected residents could require hospital care at once when the virus peaked in late May or early June underestimated the effectiveness of the county’s dramatic actions to keep the new coronavirus in check.

The county’s unprecedented March 18 stay-home order and related public health measures have had a far greater effect reducing spread of the coronavirus than previously expected, Dr. Sundari Mase, the county’s health officer, told the county Board of Supervisors during a presentation of the fresh modeling.

Once her shelter-in-place directive is relaxed incrementally - starting Wednesday with the reopening of Sonoma County parks - ramped up testing underway and ongoing virus tracking could push back a year the potential for a smaller spike of local infections, while keeping the number of people hospitalized with the infectious disease within the ability of county hospitals to treat them, Mase said the modeling shows.

“Over time, we’ve had about 22 hospitalizations,” she told the supervisors on Tuesday, speaking about the period since the first local case emerged March 2. “But at any given time, we have fortunately only had a few hospitalizations, between two and four people in the hospital at any given time.”

Blocking the worst of the coronavirus pandemic has cost thousands of county residents their jobs and many companies are struggling to survive. Now begins the equally difficult task for county elected leaders, health officials and the business community to strike a prudent balance between maintaining the public health against the reduced virus risk, while reviving a local economy that in just two months went from vibrancy to brink of recession. The complicated nature of what comes next for a county lashed by personal and economic carnage was on display during Tuesday’s supervisors’ meeting.

The new modeling, Mase said, indicates the county’s intensive tracing of close contacts of infected people and a much broader testing program in the coming weeks intended to test up to 800 people daily would help continue to flatten the viral curve, potentially keeping peak hospitalizations next year below 500 patients. That apex in local COVID-19 cases might not occur until summer 2021, according to the new modeling.

Last month, county and hospital officials coordinated efforts to add hundreds of beds to bolster area hospitals, which have nearly 700 beds, to prevent a surge in patients that would overwhelm the county’s health care system. That surge didn’t materialize because Mase said the latest modeling showed that local pandemic-related restrictions have reduced the estimated rate of spread of the pathogen by 75%. Previous modeling by Imperial College assumed the county’s move to close most businesses and order people to largely stay home would reduce that infection rate by half.

According to Imperial College, its first modeling “adopted conservative assumptions in the absence of data” and was not intended to predict what would happen. It said the initial report was aimed at estimating the “minimum level of effectiveness that (shelter-in-place) would need to achieve to prevent overwhelming capacity in Sonoma County’s hospitals.”

The new projections show the public health emergency measures in place since mid-March, along with “ongoing contact tracing, targeted testing, social distancing, face covering among other mitigation strategies have succeeded in interrupting transmission,” Imperial College said in its report.

During a press briefing Tuesday afternoon, Mase said to achieve robust coronavirus testing will require hundreds more daily tests than the volume now being conducted by the county’s public health laboratory, commercial labs and local hospitals and clinics.

“If we were to get to that 800 tests a day - 700 to 800 tests a day - we could reevaluate to see if our strategy is robust enough,” she said. “But we’ll have to see if that’s enough for our community. It’s not just the numbers of tests, it’s whom you’re testing as well.”

On Saturday as part of its testing push, the county tested about 450 health care workers at a drive-thru site in Santa Rosa. In coming weeks, the county will target testing first responders, people 65 and older with underlying health conditions and eventually those in the general public with COVID-19 symptoms.

To reach to her desired level of testing, Mase said more staff and resources will be needed. She said a shipment of 100,000 swabs for testing ordered earlier this month has not yet arrived, and the county will need more workers or volunteers to help trace contacts of additional people stricken with COVID-19 to continue to map and limit the spread of the virus. As of Tuesday night, 5,649 people among the county’s population of about 500,000 have been tested. Among the 228 people who have contracted the infectious disease, there are 121 active cases, two people died and 105 residents have recovered.

“I don’t know what time frame it would take for us to ramp up, but I’m hoping that within the next month, we’ll be there,” she said of testing.

Mase said 200 to 300 more public health workers would be needed to effectively track the virus as her stay-at-home order starts easing and more people return to work and resume more public activity.

If done right, ample testing and the systematic tracking of cases - known as contact tracing - could actually eliminate the possibility of a surge of future virus-related hospitalizations, the health officer said.

“We’re effectively doing the exact same thing as shelter-in-place, except we’re targeting it to people who are the cases,” she said. “If you use that strategy, then absolutely we are staving off a surge.”

But Mase warned that the inability to track and continue to test for the virus could throw a “monkey wrench” into the transition away from public health emergency restrictions.

“That’s when we’ll have, again, community transmission and we risk a surge at that point,” she said.

During Mase’s presentation to county supervisors, Supervisor Lynda Hopkins called on her to provide more information about how the county is meeting Gov. Gavin Newsom’s six benchmarks for lifting statewide stay-at-home home restrictions. She suggested creating a computer dashboard that shows how the county is progressing with COVID-19 testing and other indicators Newsom and state officials are using to guide the pace and specifics of the reopening of the economy and resumption of community events.

Supervisors expressed deep concerns about the mounting job losses and local business peril during the virus-induced shutdown since mid-March.

“We have done what we wanted to do, which was flatten the curve,” Supervisor Shirlee Zane said. “You know, we just look at the physical sciences in a vacuum. I think we are in danger. I think the risk is hurting a lot of people who are going to lose their livelihood and from there lose their health.”