Category Archives: Positive test rate

Dr. Richard Fleming: Letter to Benicia City Council on Benicia’s Mask Mandate

February 11, 2022
By Benicia’s Dr. Richard Fleming
(posted here with permission)

Dear Council members and Mr. Upson – Should Benicia lift its current indoor mask mandate?

My recommendation is: Not yet, but hopefully soon.
Richard Fleming, M.D., Benicia, CA

Our state is lifting the statewide mask mandate February 15. Most Bay Area counties will be lifting their indoor mask mandates the week of February 14, 2022, though the specific approach varies. Some counties will require that unvaccinated people continue to wear masks in indoor public spaces, and that masks are still required by all in some indoor spaces.

There is clearly a strong desire to return to normal life and social interactions after two years of this pandemic. There are objective signs the pandemic may be on the cusp of turning into an endemic situation, given increasing vaccination rates and increasing natural immunity. But it is apparent that different geographic areas are in different stages of moving towards endemicity. And it is also clear from our collective experience over the past two years that it is not unusual to see viral spread increase after public health restrictions are lifted in defined geographic areas.

Given these two realities, I feel our city should proceed in a measured way – relying on objective data which gives the most accurate available picture of the current state of the pandemic in our city – in deciding when to lift the indoor mask mandate. This mandate, it should be noted, has been supported and complied with by the vast majority of city residents and visitors to our city. It would be tempting to yield to feelings of exhaustion with the pandemic, but doing so may lead to policy changes we come to regret.

*    *    *

When our city council put in place the current mask mandate on August 25, 2021, it decided to use an objective metric to decide when this mandate could be lifted. When case rates in Benicia stayed in the CDC-defined moderate transmission level for 30 consecutive days, masking would no longer be required. Subsequent discussions in the council have considered using more than one metric to make a mandate-lifting decision, but no decision was made and goal numbers were not established.

Using several metrics would provide greater assurance about when it would be safe to lift the mask mandate. Any single metric has some intrinsic flaws, so a combination of several would provide a more accurate picture of the state of the pandemic in our city.

Under our current metric – case rate – we have too many cases per week to stop the mask policy. According to Resolution 21-88, we need to reach 27 or fewer cases weekly and maintain that for 30 days. We are currently at 100 new cases per week. Though this number is very high, it is trending downwards. For much of January, we were averaging 200-400 cases per week. Progress is being made, and there is reason to hope that in the weeks ahead, we will achieve a moderate level of transmission. (It is important to keep in mind the caveat that case numbers are increasingly inaccurate and reflect an undercount due to the growing use of home antigen tests. This is why adopting several metrics would provide greater accuracy.)

*    *    *

Other metrics that could be used include the following. I feel that in assessing this data, we look not just at current numbers, but at trend lines, since those can provide dynamic information on the trajectory of the virus.

  • Hospitalizations. We do not have Benicia-specific data, so Solano County data can be used as a proxy. The county is currently seeing 35 covid-19 hospitalizations per 100K residents, which is close to the highest level of the pandemic. More concerning is that our hospitalization rate is trending upwards. It has risen 48% compared to two weeks ago. Our hospitalizations are rising more rapidly than any Bay Area county other than Marin, whose hospitalization rate is only 21 per 100K. So, even though the official case-rate numbers are trending in a good direction, hospitalizations paint a more concerning picture of where our county stands.
  • Vaccination rate. Currently, 78.6% of city residents have gotten 2 shots of Moderna or Pfizer, or 1 shot of J&J. Of this number, 55% are boosted. So the proportion of city residents who are truly fully-vaccinated is 43.2%. (Boosters are proven to be crucial for optimal protection.) 35.4% of city residents received full initial vaccine doses but are not yet boosted. They do have greater immunity than unvaccinated people, or those who did not complete their initial vaccine series. There are many city residents who have some degree of natural immunity, but their level of protection is not clear. A significant proportion of people who report having recovered from covid have no detectable antibodies, and it is not clear how long antibodies persist in those with natural immunity. Bottom line, while our community’s immunity is increasing, a significant proportion of our residents remain highly susceptible to serious covid infection.

Comparing our city’s vaccination rate to nearby counties, 6 of the other 8 Bay Area counties have a higher percentage of their entire county vaccinated than does the city of Benicia. We are still lagging behind in what should be achievable vaccination levels.

  • Test positivity rate. No city data is available. Solano County’s positive test rate is 19%, compared to a statewide rate of 7%.
  • Hospital capacity, ICU bed availability, and ventilator availability. In these metrics, our county is doing fairly well, though it is also true our hospital staff and health care workers are under significant stress and are looking forward to the period when covid-19 becomes truly endemic, rather than aspirationally endemic.

*    *    *

Bottom line, I encourage you to maintain your commitment to using objective data to decide on when to lift the mask mandate. I recommend you adopt 3 metrics – cases, hospitalizations, and vaccination rates – as the data to look to. Choosing a goal for each metric, and requiring 2 of the 3 goals to be met over some period of time, would help maintain a safe environment for our city. I feel making the decision based on such measures would be widely-supported in our city. And, at whatever point you decide to lift the mandate, I recommend you also clearly advise our residents that indoor mask-wearing in public spaces is still appropriate and encouraged until the metrics improve even more, and that you also allow individual businesses to continue requiring masks of their own customers.

Sources for above data available upon request.

Thank you.

Richard Fleming, M.D.

Solano COVID test rate 2nd highest in Bay Area

[BenIndy editor: The Chronicle’s 7-day test rate numbers match the daily 7-day average numbers recently released by Solano County through July 12.  More recent numbers are available: Solano first released test numbers to the public on July 13, at 5.3%, increasing on July 14 to 6.7% and on July 15 to 7.3%.  The Benicia Independent and others repeatedly requested Solano Public Health to release positive test rate information, and it took weeks for the County to finally add the 7-day average to its daily dashboard report.  – R.S.]

Charts show how coronavirus positive test rates have roller-coastered in Bay Area counties

San Francisco Chronicle, by Kellie Hwang, July 16, 2020 

As California reverses course this week and shutters many reopened businesses in the counties on its coronavirus watch list, one crucial metric guiding health officials’ decisions is the positive test rate.

That figure, which officials refer to as the “positivity rate,” is the percentage of tests conducted that come back positive for coronavirus. The state threshold for counties to reopen faster is 8% over a seven-day period. California’s current positive test rate sits at 7.1%, and the latest 7-day moving average for the U.S. is 8.7%.

Lee Riley, an infectious disease expert at UC Berkeley, said the positive test rate is one of several ways to assess the trajectory of the epidemic, along with hospitalizations and deaths.

“The public should care because if any of these parameters are increasing, they need to know why,” he said. “They need to know who is not wearing masks and what social gathering settings are contributing to the increased spread. Then, these behaviors can be targeted for correction.”

But what does the positive test rate look like across different regions of the Bay Area, where seven counties — Alameda, Contra Costa, Marin, Napa, Santa Clara, Solano and Sonoma — are on the watch list?

We examined what the average positive test rate was over the past two weeks for each county, and compared that to the historical trendline to see how things have changed over time. For a number of counties, the changes are quite stark.

Top of the list: Marin, Solano, Contra Costa

Marin County tops the list right now with an average rate of 12.9%, the third highest in the state over the past 14 days as of Tuesday afternoon. That number includes the outbreak at San Quentin State Prison, which now has more than 1,300 active cases. The prison had zero coronavirus cases through May until the transfer of prisoners from Chino to Marin County on May 30, which led to the rapid spread.

Marin County doesn’t include the prison statistics in its reporting, and instead listed a 14-day average positive test rate of 7.1% as of July 10. But the state and The Chronicle’s Coronavirus Tracker include the San Quentin cases, which are putting a strain on local hospitals and contributing to community spread, since prison workers have also become infected.

Both of those numbers are considerably higher than what Marin was averaging at the end of May, about 3.7%, before the outbreak at the prison. And the county’s rate was just 2% in early May. Marin County has seen outbreaks in skilled nursing facilities, growing cases among essential workers and within the county’s Latino population.

Solano County currently has the next highest positive test rate in the Bay Area, at 6.3% for the 14-day period. The state points to outbreaks among farmworkers who live in Solano County but work at Napa and Sonoma vineyards. Like many other places that are reopening, county officials have tied many cases to more in-person gatherings among individuals who don’t live in the same household.

Contra Costa County is third highest at 5.1% over the past 14 days. The state reports a rise in hospitalizations paralleling the increasing infections. The 7-day average was last reported at 7.8% on July 12, and in May, it never went higher than 3.8%. The county recently implemented a stricter face mask order requiring individuals dining on restaurant patios to keep face coverings on at all times except when actively eating or drinking.

Posting the lowest rates: San Francisco, Santa Clara

San Francisco has the lowest positive test rate of any Bay Area county at 2.1% for the 14-day period. The lowest average rate it has posted on a weekly basis was 1.1% in mid-June, and the highest was 4.3% in early May.

San Francisco has been cautious about reopening, waiting until June 12 to allow outdoor dining and indoor retail. Further expansions planned for late June and early July, including hair salons and indoor dining, have been postponed indefinitely.

“San Francisco was the first county to implement the lockdowns, so it had low rates to begin with,” Riley said. “I think they’ve been able to maintain these low rates also because people have accepted social distancing practices seriously.”

Santa Clara County is the second lowest at 2.5% for the past 14 days. While Santa Clara’s positive rate has remained well below the state threshold and the average rate hasn’t peaked above 3.3%, the county has seen an increase in hospitalizations, which prompted the state to place it on the watch list.

“Many of the cases identified in Santa Clara County are from long-term care facilities, who are more likely to develop severe disease requiring hospitalization,” Riley said. “The overall number of cases is not very high, but the proportion of people developing severe disease may be higher in this county than some of the other counties.”

The county reported its biggest daily case count of the pandemic, 258, on July 8. Essential businesses in food service and construction have recently been tied to outbreaks in the county.

In the middle: San Mateo, Napa, Alameda, Sonoma

San Mateo County’s positive test rate is 3.3% for the 14-day period ending Tuesday. The county has progressed far into reopening, with less risky businesses resuming in May, indoor dining OKd in mid-June, and most other businesses allowed to open by June 19. It was the only Bay Area county still allowing indoor dining as of Monday, when Gov. Gavin Newsom’s statewide order revoked that privilege; others either suspended operations earlier or hadn’t allowed them to reopen yet.

Napa County, with a 3.7% positive test rate over the 14-day period, was the earliest Bay Area county to reopen outdoor and indoor dining, on May 20. For most of June, Napa’s weekly positive test rate was steady at 1.7%, and in late May it was as low as 0.4%. But the state reports social gatherings, an increase in transmission, especially among the Latino community, and the impact on agricultural workers contributed to a recent rise in the rate, which reached 4.7% on July 5.

Alameda County, at 4% for the 14-day period, has been among the slowest in the Bay Area to reopen. But increased social interactions and a spike in cases among essential workers and in nursing facilities prompted the state to place it on the watch list on Wednesday. The county had allowed outdoor dining to resume on June 19, but had to reverse course last weekend because of a state restriction. As of Wednesday, restaurants can reopen for patio dining again. Alameda posted its lowest weekly rate in mid-June at 3.6%. Throughout May it hovered around 5%.

Sonoma County follows with a 4.2% positive test rate over the 14-day period, and saw its highest daily case count since the start of the pandemic on July 12, when 116 infections were reported. Health officials have blamed the rise on more social gatherings, and workplace outbreaks including at skilled nursing facilities. Outbreaks have also occurred among workers at wineries. Past positive test rates are not recorded on the county website, so we were unable to chart the historical trend.

Here is the complete list of positive test rates for all 58 California counties over the 14-day period ending at 4 p.m. Tuesday:

Stanislaus: 15.2
Merced: 14.9
Marin (includes San Quentin cases): 12.9
San Joaquin: 12.6
Imperial: 12.3
Tulare 12.1
Orange: 12
Glenn: 11.8
Fresno: 11.6
Colusa: 11.5
San Bernardino: 11.2
Riverside: 10.8
San Diego: 10.2
Madera: 9.6
Kings: 8.9
Monterey: 8.7
Santa Barbara : 8.4
Sutter: 8.4
Yuba: 8.4
San Benito: 6.8
Kern: 6.7
Los Angeles: 6.5
Sacramento: 6.4
 Solano: 6.3  Yolo: 6.3
Contra Costa: 5.1
Placer: 4.9
San Luis Obispo: 4.8
Ventura: 4.3
Butte: 4.2
Sonoma: 4.2
Alameda: 4
Napa: 3.7
Calaveras: 3.6
San Mateo: 3.3
Santa Cruz: 3.2
El Dorado: 3.1
Del Norte: 2.9
Lake: 2.7
Tehama: 2.6
Amador: 2.5
Santa Clara: 2.5
Mono: 2.3
Shasta: 2.2
San Francisco: 2.1
Plumas: 2
Nevada: 1.9
Humboldt: 1.7
Lassen : 1.6
Siskiyou: 1.4
Inyo: 1.1
Mariposa: 0.9
Tuolomne: 0.8
Mendocino: 0.6
Alpine: 0
Modoc: 0
Sierra: 0
Trinity: 0
Kellie Hwang is a San Francisco Chronicle staff writer.