The Boulder County resident who tested positive for the omicron variant of COVID-19 after traveling abroad likely isn’t the only person in the community who has it, and the public should keep taking precautions against the virus, state health officials said Tuesday.

The delta variant still accounts for the vast majority of COVID-19 cases in Colorado. But the state has confirmed two cases of the new omicron variant, both in people who had recently traveled to southern Africa — and a sampling of Boulder’s municipal wastewater system picked up some of that variant’s distinctive mutations, state epidemiologist Dr. Rachel Herlihy said at a news conference.

Wastewater testing can’t pinpoint how many people may be infected, but the results suggest more than one person likely has omicron, Herlihy said. However, the new variant doesn’t appear to be widespread in Boulder.

“There’s probably some low level of community transmission,” she said.

The first omicron infection in Colorado was confirmed in an Arapahoe County woman, but state officials have not reported any spread related to that case.

Herlihy urged people who develop COVID-19 symptoms or know they were exposed to get a PCR test, which looks for the virus’s genetic material. While at-home rapid tests are a good screening tool, the state can’t use them to track which variants are spreading in the community, she said.

“Our detection system only works if people get tested,” she said.

So far, omicron doesn’t appear to be causing more hospitalizations in South Africa — where it was first confirmed — than previous versions of SARS-CoV-2, which is “reassuring so far,” Herlihy said.

It does seem to be spreading more rapidly than the delta variant, but it’s not clear if that’s because it’s more contagious, or because it’s better at infecting people who are vaccinated or who have recovered from COVID-19 infection via another variant. It’s possible both could be factors, but the world won’t know with certainty for a few weeks.