More Contagious Coronavirus Strain Found In King County

SEATTLE — A more transmissible strain of the coronavirus was detected in King County for the first time Friday, found in a test sample analyzed by UW Medicine researchers, according to public health officials.

For weeks, King County's health officer has raised the alarm that the B117 variant was likely already in the community and its discovery Friday came as no surprise. Washington's first confirmed cases of the strain were announced in Snohomish County on Jan. 23, followed by a Pierce County case confirmed the next day.

The mutation first swept through the United Kingdom, prompting lockdowns and curfews across much of Europe. The Centers for Disease Control and Prevention predicts it could become the dominant strain of the virus across the United States by March, well before a significant portion of the population is vaccinated.

Related: Health Officer Pleads For Caution As King County Begins Reopening

Just one week ago, Dr. Jeff Duchin warned against complacency and cautioned that a surge in infections linked to the new strain would mean the eruption of a "COVID-19 volcano." Hours before the announcement Friday, Duchin reiterated the need for extreme caution, especially as the state's most populous county enters the second reopening phase Monday.

"Although our levels of COVID-19 are decreasing again, they remain very high by most standards, and I need to be clear again that we should expect the variant strain to become widespread here," Duchin said. "That will make our outbreak much harder for us to control. If the outbreak takes off from a very high level of COVID-19, it will be like falling off a cliff, compared to falling off a curb."

In a news release Friday evening, Public Health - Seattle & King County said, though some unknowns remain, the more rapid spread could quickly lead to an unsustainable level of illness and overwhelm the county's health care system. Friday's discovery, officials said, should serve as a wake-up call.

"Faster spread means more people get infected, leading to more COVID-19 cases, hospitalizations and more deaths in a shorter period, and that is dangerous. A rapid increase in people with COVID-19 can quickly overwhelm our healthcare system’s ability to respond. In addition, preliminary data from the UK suggests that the variant may be associated with more severe illness, but this is not certain at this time and their evaluation is ongoing. The CDC does not currently have conclusive evidence that this variant causes more severe illness.

It’s likely that the vaccines that have been developed will still be highly effective against it, though that’s something the scientific community overall will keep a close eye on."

Despite the variant's arrival, officials said it is not too late to limit its effects by using the same proven health measures that guard against all strains of the coronavirus. As the county enters its second reopening phase Monday, restoring more indoor and social activities, the core public health guidance has not changed: Minimize contacts with those outside the home, wear a well-fitting mask near people you don't live with, wash your hands often, avoid crowded indoor spaces and areas with poor ventilation, and don't hesitate to seek testing.

"If you have symptoms of COVID-19, isolate yourself away from others and get tested. Stay in isolation while waiting for your test results and until your healthcare provider or a Public Health investigator lets you know when to end your isolation (usually 10 days after symptom onset if you are improving and have not had a fever in at least 24 hours). The person with COVID-19 and others in the home should wear masks until all ill people are out of isolation.

If you think you have been exposed to someone with COVID-19, get tested even if you don’t have symptoms and be diligent about quarantining and staying away from others, including wearing a mask in your home around other people."

Read more about the best ways to guard against the variant strain on the Department of Health website.