Facing a resurgence in COVID-19 infections, the California Department of Health moved Contra Costa County back to the more restrictive red tier this week according to the guidelines in the Blueprint for a Safer Economy.

In a press release issued Tuesday, Nov. 10, Contra Costa Health Services (CCHS) said the move was intended to slow the virus and save lives.

According to CCHS, most new COVID-19 cases in Contra Costa are spread within the home, when an infected member of a household passes the virus to people with whom they live. Face coverings in public reduce the risk of bringing COVID-19 into the home, where people usually do not mask or practice physical distancing.

“The most critical way to protect against COVID-19 is to wear a face covering whenever you are near people who do not live with you, and whenever you go in a building that is not your home,” said Dr. Chris Farnitano, Contra Costa health officer. “Face coverings help prevent people who do not know they are infected from spreading the virus to others. My mask protects you. Your mask protects me. Masks also provide some direct protection for the wearer.”

Data from Contra Costa shows that the average daily number of newly identified COVID-19 infections has risen steadily since the county entered the orange tier of the state’s plan on October 27.

On Tuesday, the seven-day average adjusted case rate was 5.3 new cases per day per 100,000 residents in Contra Costa — higher than permitted for counties in the orange tier for a second consecutive week. Two consecutive weeks of declining metrics resulted in the county’s backslide into the red tier. CDH guidelines for the orange, or moderate, tier require an adjusted case rate of 1.0 - 3.9. An adjusted case rate of 7.0 or higher will move the county into the most restrictive purple tier.

The second measurement that determines a county’s tier assignment is the positivity rate, which is the percentage of COVID-19 tests that return a positive result. Contra Costa County reported a positivity rate of 2.4% when the weekly assignment was last calculated. The orange tier requires a positivity rate from 2.0% to 4.9%. A positivity rate higher than 5% will trigger a county into the red tier, while a rate higher than 8% will result in an assignment to the purple tier.

The number of hospitalized COVID-19 patients is not a measurement used for tier assignment, but it is still closely monitored by the county. Hospitalization peaked at 110 on July 30 and then declined steadily until it reached a low of 17 on Oct. 14. Since then, the number of hospitalizations has been trending back up. As of Nov. 10, it stands at 45.

There have been 20,418 confirmed COVID-19 cases in the county since the first case was reported in March. The county has reported 253 deaths related to the disease.

In response to the worsening data, Contra Costa Health Services (CCHS) issued a local health order last week that restored red-tier safety restrictions for a number of businesses and activities, though the county remained in the orange tier at the time. Those changes remain in place, including requirements for reduced occupancy during indoor worship services and for indoor dining and movie theaters, and the closure of bars that do not serve meals with alcohol. Cardrooms are required to operate outdoors only.

“We understand the need to move back into the more restrictive tier based on the data,” said Tim Ogden, Brentwood city manager. “We fully appreciate the community’s fatigue with the pandemic, but encourage greater vigilance in following the rules for everyone’s sake. Our business owners are impressive with adapting to the roller coaster of restrictions, and we applaud their continued creativity and perseverance.”

Red tier restrictions take effect Friday, Nov. 13 in Contra Costa. Included in those restrictions:

Retail stores that operate indoors must scale back their maximum occupancy to 50% or 100 people, whichever is lower.

Indoor shopping malls must reduce their occupancy and reduce the occupancy of food courts to 25% or 100 people, whichever is fewer.

Office workspaces must operate remotely.

Higher education institutions must keep indoor lectures and student gatherings to 25% occupancy or 100 people, whichever is fewer.

Gyms and fitness centers must scale back their indoor occupancies to 10%.

Communal indoor pools must close.

Indoor family entertainment centers, such as bowling alleys, must close their indoor operations. Amusement parks cannot operate.

Most live outdoor theatrical, musical or artistic performances are prohibited.

The tier change does not affect the ability of schools to reopen for in-person instruction, following state and local health guidelines. Outdoor playgrounds may also remain open.

Visit cchealth.org/coronavirus for local information about COVID-19.