At least 10 new omicron cases – including six in King County – have been confirmed in Washington state, indicating an “explosively fast” spread of the new variant throughout the region, local and state health officials announced Wednesday afternoon.

Few details about the additional omicron infections were available Wednesday. Of the six King County residents infected, immediate information was available for only three, county health officer Dr. Jeff Duchin said in a news briefing. None of the three have been hospitalized, he said.

While the three residents reported recent travel within the United States, none have traveled internationally, meaning omicron is circulating locally, Duchin said. All three were fully vaccinated, and one had received a booster dose.

There’s no evidence yet that the six new King County cases are linked to each other nor to the first case identified in the county, which was announced in early December. There are now 10 confirmed cases of the variant in the state, though health officials and researchers say the number is likely much higher.

“Although delta currently makes up the vast majority of cases in King County and regionally, omicron virus spreads explosively fast,” Duchin said. “I expect we’ll see a rapid increase in omicron in the coming days and weeks.”

The cases outside King County are connected to multiple outbreaks linked to high school wrestling tournaments in Lacey, Sumner, Puyallup and Yelm earlier this month. Duchin said that as of Tuesday night, Public Health – Seattle & King County has been notified of 82 cases associated with the wrestling tournaments across 20 schools in the state.

The state Department of Health recommends that anyone who attended these tournaments monitor for symptoms and get tested for COVID-19. Local health jurisdictions are also likely to send out notifications to the impacted schools with further guidance, DOH said.

“It’s really important to understand we don’t have all the answers about omicron currently, and a lot remains uncertain about how this variant will affect us,” Duchin said. “But we do know enough about omicron to take it very seriously and to take steps to decrease our risk.”

As of this week, researchers throughout the world have found increasing evidence that shows the new variant is “significantly” more transmissible than the delta variant, and also spreads primarily through the air in indoor spaces, Duchin said.

“The number of cases in several countries that recognized omicron earlier than the U.S. is doubling every two or three days,” he added.

Early evidence shows strong signs the new variant is also spreading quickly throughout the state, according to the University of Washington’s virology lab, which has been sequencing the coronavirus since the start of the pandemic.

To find signs of the variant, the lab – like many others throughout the country – has started running all positive samples through a particular PCR test that searches for a mutation called spike-gene target failure (SGTF), or a small deletion in the omicron variant’s spike protein.

“It’s an early indicator of which samples might be omicron, by virtue of the fact that they bear a very specific mutation, which allows us to pick them up,” said Pavitra Roychoudhury, acting instructor of the University of Washington’s department of laboratory medicine and pathology and researcher in the school’s virology lab.

As of Wednesday morning, Roychoudhury said about 20% of all positive COVID samples have the SGTF mutation, meaning about a fifth might be omicron. Last week, about 13% of samples had the mutation, Roychoudhury said on Twitter.

While the mutation doesn’t definitively identify the variant – confirmation is done through genetic sequencing – the lab can use the SGTF as a “proxy for an approximate number of omicron cases in the population,” Roychoudhury said.

Roychoudhury said she and her team previously used the assay in January, to search for the alpha variant, which shares a similar mutation to omicron.

“It certainly suggests that this is a highly transmissible variant given that we’re detecting this increasing percent of these cases over time,” she said. “But how this is going to hold up against delta in our specific geographic region is something that remains to be seen.”

The high transmissibility shouldn’t be a “cause for panic,” Roychoudhury said. Instead, she said she hopes knowing that might motivate people to change certain habits, such as increased masking and distancing.

Duchin during the Wednesday briefing also renewed a push for vaccinations and boosters, which early data show are protecting against serious disease from the omicron variant even if they’re not as effective against infection.

“Everyone should be prepared for eventually many of us being infected,” Duchin said. “Being infected doesn’t mean getting seriously ill.”

In addition to getting vaccinated and boosted, recommended layered prevention methods include wearing fitted masks, improving indoor air ventilation and air quality, distancing and avoiding “high-risk environments.”

Even if most people don’t get seriously ill from the variant, having a large number of patients get sick in a short period of time could be a problem for the state’s already overburdened health care system, as well as businesses and companies that rely on having a consistent number of employees show up, Duchin said.

“The emergence of omicron is a disappointing setback in where we hoped to be two years into this pandemic,” he said. “… Despite this, we’re not going back to square one of the pandemic. We have effective vaccines to prevent serious illness and we know what works to prevent COVID-19 spread in the community. And overtime, I’m confident that increasing immunity from vaccination and some exposure to the virus will make COVID-19 less and less of a threat.”