The omicron variant of coronavirus has been detected in Spokane, Benton, Franklin and Yakima counties, health officials confirmed Wednesday in the state’s latest variant report.

There has been just one detected case of the highly contagious variant in Spokane County as of Wednesday, but officials caution there almost certainly are many more cases that haven’t been detected.

State sequencing data is delayed several days, and just 6% to 12% of positive COVID samples in Spokane County are sequenced for variants.

That means one confirmed omicron case actually indicates that the new variant is circulating locally.

“We don’t have enough data here locally to see how omicron will affect our numbers or hospitalizations, but judging by what we’re seeing around the country, it is overcoming delta and becoming the dominant variant, and we expect that to happen here too,” said Kelli Hawkins, Spokane Regional Health District spokesperson.

The variant so far appears to be more transmissible than the delta variant.

Of positive samples sequenced statewide from Dec. 5 to Dec. 18, omicron made up nearly 25%, while the delta variant made up 75%. The previous two weeks, omicron made up just 0.2% of variant samples sequenced, indicating its rapid growth in the state.

Last week, omicron made up more than 58% of sequenced cases nationwide, according to the Centers for Disease Control and Prevention.

The new variant also is causing breakthrough cases in those who have been vaccinated, but the delta variant continues to cause more breakthrough cases.

Many Washington residents who have tested positive with the omicron variant are reporting some symptoms.

The most common symptoms from omicron include a headache, sore throat, cough and muscle aches, according to the Department of Health.

The rapid spread of omicron led the CDC to change recommended isolation and quarantine guidance, especially for those who are asymptomatic but test positive.

People who test positive for COVID-19 now only need to isolate for five days instead of 10, as long as they are asymptomatic on their fifth day and wear a mask when around others for the five days after that. If symptoms occur, an individual must quarantine until they test negative.

If a person is exposed to someone with the virus, that person no longer need to quarantine if they have been boosted, although the person should keep wearing a mask for 10 days after the exposure. A person who is fully vaccinated, but not boosted, or unvaccinated, should quarantine for five days followed by five days of strict mask use when they are exposed to the virus.

The CDC is recommending testing on the fifth day after exposure. The Department of Health has affirmed these changes to isolation and quarantine guidance.

Due to omicron, the CDC also changed recommendations for health care workers when it comes to isolation and quarantine after testing positive or being exposed to the virus.

That guidance is dictated by how stretched a hospital is and the vaccination status of the worker, as well as whether they have symptoms.

There is still limited data on the omicron variant, but preliminary reports show that it has produced more mild illness.

A small household outbreak in Nebraska studied by CDC researchers found that both people who were vaccinated and those who were previously infected with the virus in 2020 all tested positive with the omicron variant. In a household outbreak where no one had underlying health conditions, no one was hospitalized with the variant.

The study also found that the index patient, who brought the virus to their household, tested negative with a rapid test before returning home from a conference in Africa. They had unmasked contact with household members two days after testing negative and did not experience symptoms until three days after testing negative. After the symptoms began, they did test positive, as did those in their household they exposed to the virus.

Health officials still are asking people to get vaccinated, get a booster dose if they are eligible and wear more protective masks like KN95 or N95 masks to keep transmission of omicron lower.

Local hospital leaders are still wary of the numbers game that a fast-spreading and highly transmissible variant like omicron could pose to an already full health care system. Hospitals are at 91% occupancy statewide, and ICU occupancy is just below 90%.

Case counts already appear to be increasing in Spokane County. In King County, case counts began increasing last week. For the past two weeks, daily case counts in Spokane County were less than 100 on average. This week, the district has confirmed more than 100 cases each day, including 272 confirmed Wednesday alone.

Hawkins said the demand for testing locally has increased in the past two weeks. Earlier this month, the community testing sites were processing 200 to 300 tests per day. Recently, the sites have been doing about 700 tests per day.

Rapid antigen testing is no longer available on New Year’s Eve at the Spokane Falls Community College on a drive-up basis because all of the available tests have been claimed through online appointments. The free at-home test kits available to residents in Eastern Washington have all been claimed .

There still is PCR testing available at some county libraries, and some local pharmacies have at-home tests for purchase or drive-through testing.

In the new year, the community testing sites will still be open and available for drive-up testing and reservations starting on Monday. Spokane County will have community-based testing sites through March.

A look at local numbers:

The Spokane Regional Health District reported 272 new COVID-19 cases and one additional death on Wednesday.

There have been 1,151 deaths due to COVID-19 in Spokane County residents.

There are 65 COVID patients hospitalized in Spokane.

The Panhandle Health District reported 109 new virus cases and four additional deaths.

There have been 783 deaths due to COVID-19 in Panhandle residents.

There are 60 Panhandle residents hospitalized with the virus.