A staff member dressed as a smiling, red-nosed Christmas tree strolled through the emergency department at a San Jose hospital on Christmas Day, hoping to provide holiday cheer.

Days later, a coronavirus outbreak swept through the Kaiser Permanente San Jose Medical Center, eventually infecting 43 employees and killing one.

Hospital officials now say the “air-powered” Christmas costume is likely to blame for the 44 positive tests, all recorded between Dec. 27 and Friday. Experts said the fan inside the costume could have blown coronavirus-laden droplets throughout the department.

“Obviously this is a highly unusual situation involving a well-intentioned staff member acting on their own without advance notice or approval,” said Irene Chavez, the hospital’s senior vice president and area manager, in a statement to The Washington Post. “Any exposure, if it occurred, would have been completely innocent, and quite accidental, as the individual had no covid symptoms.”

Late on Sunday, the hospital announced that a registration clerk in the emergency department had died of covid-19, NBC Bay Area reported. The woman was among the staffers who worked in the emergency department on Christmas Day and later tested positive. Employees told the station that they were devastated by the loss and described her as an “absolutely wonderful woman.”

The outbreak comes as covid cases in California surge and hospitals struggle to keep up. This past week, hospitalizations in the state rose 7 percent, according to The Post’s covid tracker. The state also confirmed last week that a Southern California patient had the second confirmed infection in the U.S. of what scientists believe to be a more contagious coronavirus variant first identified in Britain.


Santa Clara County, where Kaiser Permanente San Jose Medical Center is located, has had more than 73,600 cases and 747 deaths. According to the county’s coronavirus dashboard, almost 700 people are currently hospitalized and about 160 are in the intensive care unit. The non-ICU beds are at 100 percent capacity and ICU beds are 91 percent full.

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The outbreak at the San Jose hospital was likely fueled by a battery-powered fan, which blew air through the holiday-themed costume to keep its shape. Because the virus primarily spreads through airborne transmission and respiratory droplets, according to the Centers for Disease Control and Prevention, the fan could have circulated the virus as the staffer made their way through the emergency department.

Even if the costume isn’t to blame, experts told the San Francisco Chronicle that the outbreak had to have been spread through the air given the number of people infected.

The hospital is still investigating the outbreak and using contact tracing to inform employees and patients who may have been exposed, Chavez said. Additionally, all emergency medical staff are being tested and the department is undergoing a deep clean. Those who tested positive were told to stay home and quarantine, Chavez said.

“We will ensure that every affected staff member receives the care and support they need,” Chavez said. “The health and safety of our patients, employees, and physicians is our highest priority.”


Chavez added that air-powered costumes are no longer allowed in Kaiser Permanente facilities. The incident has caused the hospital to “reinforce” safety protocols among staff, the hospital’s vice president said, “including physical distancing and no gathering in break rooms, no sharing of food or beverages, and masks at all times.”

Despite nearly 40,000 Kaiser Permanente health-care workers in Northern California having already received the first dose of the coronavirus vaccine, according to Chavez, the outbreak in San Jose was a reminder that it takes time to build immunity.

“Given the prevalence of covid-19 in the community we are all still vulnerable and it remains critical for everyone to continue using the methods to help protect ourselves and others,” Chavez said.

She added that the costume incident “should serve as a very real reminder that the virus is widespread, and often without symptoms, and we must all be vigilant.”