Alameda County moved to California’s purple tier as COVID-19 cases and test positivity rise

Dr. Moss, Alameda County’s health officer, told the Board of Supervisors on Nov. 17 that county case counts and test positivity have risen sharply in recent days, reporting 25,872 cumulative cases and 490 deaths as of Nov. 16. He said hospitalization indicators are increasing and that the state placed Alameda County into the purple (most restrictive) tier using more recent data and a shortened assessment window.

"We were on the threshold of the red and purple tier, and given day-over-day increases, they placed us directly into the purple tier," Dr. Moss said, adding that the county "skipped the red tier completely." He said the purple-tier restrictions take effect tomorrow at 12:01 a.m. and will close many activities previously allowed in red or orange tiers, including indoor dining, movie theaters and indoor family entertainment. Outdoor dining and certain outdoor activities remain permitted.

The county’s case rate and test positivity metrics, Dr. Moss said, have been rising for about 10 days and have roughly doubled in recent weeks. "This is not yet to the levels we saw during our summer surge, but it is a very concerning day-over-day rise," he said. He cautioned that the impact of any new restrictions will take weeks to appear in surveillance data and urged residents to "wear masks, physically distance, stay home when sick, and wash hands frequently."

Supervisors pressed officials about schools and waiver processes. Dr. Moss said the state had only clarified details about school waiver ability in the previous 24 hours and that the county does not currently have a new waiver process for elementary schools. "We didn't know our tier assignment until Sunday evening," he said, noting the state's intent to make tier assignments more responsive to rapid changes.

The board asked staff to publish local guidance summarizing which activities remain allowed under the purple tier and to continue close coordination with the state on any further changes.