King County health officials investigate COVID-19 outbreak related to delta variant

Sixteen positive cases have been reported. At least five of the cases had sequencing results indicating the infection was due to the delta variant.

SEATTLE — Officials with Public Health – Seattle & King County are investigating an outbreak at a Seattle fitness center where several people who reported being fully vaccinated tested positive for COVID-19. 

King County’s Health Officer Dr. Jeff Duchin discussed the outbreak during a media briefing Friday. Duchin said the health department was notified July 6 of six people who tested positive for the virus who recently spent time at the fitness center – Duchin did not provide the name of the facility. 

According to Duchin, the facility hosted a charity workout event on June 26 with 70 people in attendance, including members, staff and non-members. 

As of July 28, county health officials have identified 16 attendees and one household member of an attendee who have tested positive for COVID-19. At least five of the cases had sequencing results indicating the infection was due to the delta variant, Duchin said. 

The health department verified that 14 of the people were fully vaccinated against COVID-19, and the other two said they were, but it was not verified. 

All of the individuals developed symptoms, but none were hospitalized. 

The fitness center voluntarily closed down after the outbreak was reported and is working with health officials to improve conditions. 

Health officials attributed the spread to several factors – the delta variant, an inadequate ventilation system, lack of physical distancing and prolonged time together. Duchin said the facility was also not requiring masks for fully vaccinated individuals. 

“This is an example of the type of venue where even vaccinated people need to take precautions,” said Duchin, who was among the first officials in the state to recommend residents go back to universal mask-wearing in indoor public spaces. It was a move echoed this week by Gov. Jay Inslee and the Centers for Disease Control and Prevention.

During Friday’s media briefing, Duchin went on to talk more about the delta variant and its predominance in the county. The latest data shows that 78% of the sequenced cases in the county are due to the variant. 

He said that evidence shows delta variant patients experience symptoms after two to three days of infection, much faster than other variants of the virus, and reaffirmed that vaccines are still highly effective against all known variants.

Duchin also addressed breakthrough cases, or cases where fully vaccinated individuals test positive for COVID-19, and cleared up some misconceptions. 

“Breakthrough cases for any vaccine are normal and an expected phenomenon as more people are vaccinated,” said Duchin. “We know vaccines are not 100% protective, no vaccines are, the main purpose of these vaccines is to prevent serious infections, not any infections, not mild infections, so calling mild or asymptomatic cases breakthrough cases is a bit misleading in that these are less serious infections and not really what the vaccine is intended to prevent.”

Breakthrough cases are rare. According to Duchin, in all of King County, there have been 1,489 breakthrough cases, which represents less than .1% of the vaccinated population.

Duchin stressed that vaccinations continue to be the biggest protector against developing serious illness from COVID-19. According to Duchin, over the past 30 days in King County, residents who are not fully vaccinated were 10 times more likely to test positive for COVID-19. 

On a positive note, Duchin shared that the latest data shows 81% of eligible King County residents have initiated their vaccination. This means that roughly 680,000 residents remain unvaccinated, however, including about 300,000 children under the age of 12.