Washington state health officials are investigating coronavirus outbreaks that occurred at two nursing home facilities after some staff attended a 300-person wedding.
Between the two Grant County facilities — Lake Ridge Center and Columbia Crest Center — officials have reported 23 deaths.
One additional death that "can be directly linked to an attendee of the wedding" was reported at a nursing home facility in Ephrata, the Grant County Health District said in a press release Thursday.
The agency said it was not naming that facility "to protect the identity of the individuals involved and their protected health information."
Health officials said in the press release that three long-term care facility staff members self-identified themselves as guests at a Nov. 7 wedding in Ritzville, about 59 miles southwest of Spokane.
The staff — two who work at Lake Ridge and a third who works at the Ephrata center — worked while contagious but did not know they had the virus, health officials said.
The outbreak at Lake Ridge Center in Moses Lake resulted in 65 residents testing positive for COVID-19 and 15 deaths, according to the press release.
At Columbia Crest Center, also in Moses Lake, 27 residents tested positive for the virus, and eight died.
Each facility has three deaths pending review, the health department said. Calls to both centers were not immediately returned Friday.
Theresa Adkinson, a county health department spokesperson, said via email Friday that the deaths at Lake Ridge and Columbia Crest have not been directly linked to the wedding.
"Through our investigations, we have learned that the staff cares for all residents throughout their shifts," Adkinson said. "All of the cases that died tested positive after the wedding. The facilities do twice a week testing prior to the wedding and have continued this regimented testing."
An outbreak at a third facility, McKay Healthcare & Rehab Center, was initially investigated as to whether it was associated with the wedding, but officials said Thursday that it began several weeks before the ceremony.
“GCHD staff and I wish to extend our most sincere condolences to the families who have lost their loved ones and to our communities affected by these tragic deaths of our most vulnerable community members," county health officer Alexander Brzezny said in a statement.
"We also extend our encouragement and sympathies to the many dedicated healthcare staff and community members who have joined us on this fight against our common enemy."
The health department said that during its investigation, it learned that some staff at Columbia Crest may have attended the wedding.
"The staff diagnosed with Covid-19 we were able to interview did not self-identify as attending the event so we cannot conclusively link wedding attendees to this outbreak," the agency said.
The health department had previously said that the wedding drew more than 300 people. At the time of the event, Gov. Jay Inslee's executive order capped wedding receptions at 30, according to the Tri-City Herald.
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According to health officials, 50 Grant County residents diagnosed with the coronavirus self-identified themselves as attending the ceremony.
Eleven other Covid-19 cases were reported in two additional counties, according to the press release.
"Through our investigations, we know there were additional probable cases who were symptomatic close contacts of confirmed cases who chose not to go in for testing," Grant County officials said.
The wedding has also been linked to coronavirus cases at the Moses Lake School District. Health department officials said that 11 staff members who tested positive for the virus self-identified as attending the ceremony. An additional staff member was also diagnosed with Covid-19, according to the press release.
Officials have not released details about the wedding or the couple. In a Nov. 17 press release, the health department said it could not enforce the governor's rule on large gatherings and cannot issue fines to people who do not follow it.
This story first appeared on NBCNews.com.