Colorado public health officials are expanding their search for the new omicron variant of the coronavirus — including by monitoring communities’ wastewater — and said Tuesday that it’s just a matter of time before the new strain is detected in the state.

Omicron, which has not yet been confirmed in the U.S., was identified last week as having been discovered in South Africa. But officials said Tuesday it had been detected in the Netherlands at least a week before the World Health Organization labeled it a “variant of concern.”

Emily Travanty, director of Colorado’s state lab, said during a news briefing Tuesday that the state is reviewing a portion of all positive COVID-19 tests to look for the variant.

“We continue to ensure that we are getting (test) samples in from all across the state and make sure we are seeing a subsampling of everything that is happening in the environment,” she said, adding, “I’m confident that… we are able to see omicron when it does appear in Colorado.”

Public health officials are concerned that mutations found in the omicron variant could make it more transmissible or that immune response may not be as effective, which could raise the possibility of reinfections, said Dr. Rachel Herlihy, the state epidemiologist, during the briefing.

However, she stressed that there is still much that remains unknown about the variant, including the severity of illness that it may cause.

“The reality is we do have a lot to learn still,” Herlihy said.

Colorado’s health department is searching for the omicron variant using diagnostic testing and clinical sequencing. About 16% of all positive PCR tests are genetically sequenced by the state in an effort to identify which variant of COVID-19 has infected the person, according to the agency.

But public health officials believe the state’s wastewater surveillance program, which began in August 2020, will discover the presence of the new variant more quickly than other methods. The health department updated the program this weekend so that it can now detect genetic markers of omicron in wastewater.

Almost 50% of people with COVID-19 shed the virus in their stool even if they don’t have symptoms. So the state is partnering with 21 utilities to identify the virus and detect specific variants within broader communities via their wastewater, said Rachel Jervis, an epidemiologist with the health department. But wastewater monitoring cannot identify COVID-19 infections in individual people.

That wastewater surveillance is how the agency first confirmed the delta variant’s presence in Colorado, she said. The first delta infections were discovered in Mesa County in May.

Before that, however, Colorado was the first state to identify a COVID-19 variant in the U.S. when it detected what later became known as the alpha variant in Elbert County last December. That case was confirmed by the state lab and was notable because public health experts said the U.S. lacked the infrastructure needed to quickly find genetic variations of the coronavirus.

The more contagious delta variant is driving the state’s most recent surge in COVID-19 cases, with it making up most cases since July, Travanty said.

The state is in the middle of one of its worst waves of the pandemic, and while public health officials said the decline in new COVID-19 cases and hospitalizations in recent days is a sign that the situation is improving, they cautioned that the Thanksgiving holiday could be skewing the numbers as fewer people get tested and data can lag around the holidays.