SACRAMENTO (CBS13) — While no official cases of the omicron COVID-19 variant have been found in Sacramento County just yet, public health leaders confirm that it has been detected in sewage samples.

Sacramento County Public Health says they were alerted last week about the findings.

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Low concentrations of the HV69-70 mutation – which officials say is being used to mark the omicron variant – were present in the sample, which was collected back on Nov. 30.

County officials say wastewater surveillance has been an important tool in helping identify the COVID variants and how they’ve spread.

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“We continue with other tools, including identifying specimens to prioritize for whole genome sequencing, as we cannot possibly sequence EVERY test result,” public health officials said in a statement.

California is one of several states have had a confirmed case of the omicron COVID-19 variant. That first official case was found in the San Francisco area.

Public health leaders have been on high alert due to the omicron strain’s apparent resistance to existing vaccines and its potential to cause a new wave of infections.

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The delta variant remains the predominant COVID-19 strain in the area, public health leaders say. People are being urged to use the same previous strategies – masking up, getting vaccinated, and quarantining if they test positive – to stop the spread.