The omicron variant is driving the largest spike of COVID-19 cases so far in Routt County, with the most recent seven-day period reporting 337 new cases.

According to Routt County Public Health, 80 new cases were reported Dec. 26, the most on any single day since the start of the pandemic. The two-week case total of 423 is a new record as well, surpassing the previous high from last January by more than 100 cases.

“We are seeing more community spread and higher test positivity rates than we have at any time in the pandemic,” said Routt County Public Health Director Roberta Smith in a joint news release with UCHealth Yampa Valley Medical Center.

The current positivity rate nearing 14% locally is also the highest it has been since the early days of the pandemic. Nearby Summit and Pitkin counties are each in the top five in the nation for cases per capita, according to The New York Times. Routt County has the fifth highest incidence rate in Colorado.

The omicron variant has rapidly become the dominant variant, now making up more than 90% of cases in the state, according to the Colorado Department of Public Health and Environment.

Omicron’s dominance has come much faster than it did with the delta variant. Omicron first appeared in sequencing at the end of November and it became dominant four weeks later. In comparison, delta took eight weeks to become dominant and 12 weeks to become responsible for 90% of cases, according to state data.

In an email to parents on New Year’s Day, Steamboat Springs School District Superintendent Brad Meeks said the surge in cases could complicate the spring semester, which starts when students return to school on Tuesday, Jan. 4.

“We may have a bumpy re-entry to the second half of the school year with staff and students absent due to illness,” Meeks said, referencing an assessment by the district’s registered nurse Cathy LaPointe.

Meeks stressed the goal is keeping students in the classroom as much as possible and that updated quarantine guidelines from the Centers for Disease Control and Prevention could help the district weather potential staff shortages.

If a student or staff member tests positive without symptoms or symptoms are improving, they can return to school after five days, provided they don’t have a fever. If symptoms persist past five days, they should continue to isolate until they haven’t had a fever for 24 hours and other symptoms have improved.

Students and staff should isolate for five days after symptoms onset, if that happens after a positive COVID test.

“We anticipate that there may be instances where we are unable to operate schools or classes in-person,” Meeks said. “However, with these adjusted isolation guidelines, we anticipate being able to get back to in-person learning quickly.”