9 US coronavirus patients — including 4 who died — have ties to a nursing home near Seattle. Here’s how the outbreak may have spread in Washington.

The entrance to Life Care Centre of Kirkland on February 29, 2020. David Ryder/Getty Images

Four of the six coronavirus deaths in the US are linked to a nursing home in Kirkland, Washington.

An outbreak at the facility, called Life Care Centre, has infected at least eight residents and one healthcare worker. At least 27 residents and 25 staff members have shown symptoms of the virus, King County public health officer Jeffrey Duchin said on Saturday.

Most of the facility’s residents are older people with preexisting health problems – the demographic most likely to develop severe cases of the virus. The Life Care residents who have died thus far include patients in their 70s and 80s with underlying health problems.

A recent study from the Chinese Centre for Disease Control found that the risk of dying from the coronavirus is dramatically higher among patients in their 70s and 80s: Patients older than 80 have a 15% chance of dying, while patients in their 70s have an 8% chance of dying.

Life care centre
Healthcare workers transport a patient on a stretcher into an ambulance at Life Care Centre of Kirkland on February 29, 2020. David Ryder/Getty Images

Since the coronavirus can be transmitted through bodily fluids like saliva or mucus, people living in close quarters can easily pass the virus to one another. Residents at Life Care share a dining room, barber shop and beauty salon, library, and putting green, according to the centre’s website.

All residents at Life Care were told to stay in their rooms on Friday after some residents began showing symptoms, The New York Times reported. Dubin said the facility has around 108 residents plus around 180 staff.

In an online statement on Sunday, Life Care said that any resident with an elevated temperature, cough, or shortness of breath was being placed in isolation. The facility is no longer accepting any visitors.

Firefighters who visited the facility around the time of the outbreak were quarantined on Sunday as well.

Washington could already have hundreds of cases

Life care centre
A woman disinfects her hands as she leaves the Life Care Centre on February 29, 2020. Jason Redmond/AFP/Getty Images

Health officials have yet to confirm “patient zero” at the facility, but researchers at the Seattle Flu Study have an idea of how the virus may have spread in Washington.

The researchers recently sequenced the genome of the virus in a case reported in Snohomish County on Friday. The team predicted that the case was linked to the first patient reported in the US: a 35-year-old man from Snohomish County.

One of the study’s researchers, Trevor Bedford, tweeted on Saturday that the virus might have been introduced to the Washington community via that first patient on January 15, five days before the patient’s diagnosis was publicly announced.

“I believe we’re facing an already substantial outbreak in Washington State that was not detected until now due to narrow case definition requiring direct travel to China,”

As of Sunday, he estimated, the number of infections in Washington may have reached 570.

The state has reported 18 cases so far. In total, the US has reported nearly 100 cases of the coronavirus. More than 90,000 infections and 3,000 deaths have been confirmed worldwide, the majority of which are on the Chinese mainland.

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