As It Happens

Inflatable costume investigated as link to COVID-19 outbreak at California hospital

A coronavirus outbreak at a San Jose, Calif., hospital may have started when a staff member wore an inflatable costume to cheer people up on Christmas Day. 

Staff member at San Jose hospital wore the costume to cheer up staff and patients on Christmas Day

The Kaiser Permanente San Jose hospital is facing a coronavirus outbreak that may be related to an inflatable costume worn in the emergency department on Christmas day to cheer up staff and patients. (Google Street View)

Story Transcript

A coronavirus outbreak at a San Jose, Calif., hospital may have started when a staff member wore an inflatable costume to cheer people up on Christmas Day.

Forty-four staff members at Kaiser Permanente San Jose Medical Center tested positive for COVID-19 between Dec. 27 and Jan. 3, according to a hospital statement. One person died from COVID-19 complications. 

The hospital says it is investigating whether an "air-powered costume" may have contributed to the spread of the virus after a staff member wore one briefly in the emergency room on Dec. 25. NBC Bay Area reporter Marianne Favro identified the costume on Twitter as an inflatable Christmas tree. 

"It was tragic on two fronts," Dr. Peter Chin-Hong, a San Francisco infectious diseases specialist, told As It Happens host Carol Off. 

"Tragic in the sense that so many people were infected, and including somebody who died. And tragic in another sense in that we've been so starved of joy and light and laughter during these bleak months that an inflatable costume would potentially be the cause of this is really saddening."

'Fans that blow continuously'

Chin-Hong, a professor at the University of California San Francisco, is not affiliated with the hospital where the outbreak occurred, and is not a part of the investigation into its cause. 

But he says an inflatable costume makes a lot of sense as a vector for spread, given what we know about the airborne virus. 

"These inflatable costumes, they are generated by these fans that blow continuously. And the reason why the fan blows continuously is because there's no perfect seal between the costume and the outside," he said.

"The fact that you have to continuously generate air pressure inside suggests that that leak is actually an important feature — and it comes back to haunt when you think about COVID transmission."

A spokesperson for Kaiser said in an email the hospital is moving quickly to test any potentially exposed patients and staff and clean the facilities. 

"Any exposure, if it occurred, would have been completely innocent, and quite accidental, as the individual had no COVID symptoms and only sought to lift the spirits of those around them during what is a very stressful time," the hospital said. 

"Obviously this is a highly unusual situation involving a well-intentioned staff member acting on their own without advance notice or approval. We are reinforcing with our staff that we do not allow these devices in our facilities."

The hospital did not say whether the person in the costume has since tested positive — but Chin-Hong says the fans likely played a role in spreading the virus, no matter where it came from. 

That's because when you move air around, it turns droplets into smaller particles called aerosols, he said, pointing to a December study out of South Korea that found air conditioning systems increased the spread of coronavirus in restaurants, even when customers were seated more than two metres apart. 

"It's kind of like liquid in the hairspray can. When you press it, these droplets become very fine. And when they become fine, they become lighter and can sort of float around the air like dandelions," he said.

"Early in the pandemic, we just had the three W's — wearing a mask, washing your hands and watching your distance. We added a fourth W in the last few months, which is watching the wind."

Kimberly Prather, an atmospheric chemistry professor at University of California San Diego, cautioned that the virus can easily spread in an indoor setting, inflatable costume or no.

"There's no other way [44] people caught it except for through the air," Prather told the San Francisco Chronicle. "This is just further evidence that the air is important. I'd be less focused on the poor person who had air in their costume."

No one to blame, says doctor

Chin-Hong doesn't blame the costume-wearer, either.

"Of course, this person didn't mean to do it. No one can think about these risks. They are not well publicized by public health departments," he said.

"Of course, when we look back, it's an 'aha' moment. But certainly that person should not feel at all responsible, in my opinion."

Nor does he blame the staff who came into contact with the costume. In fact, he says he probably would have welcomed it himself. 

"I think I would have approached it with excitement and joy and laughter and probably let down my guard a little bit."


Written by Sheena Goodyear. Interview with Dr. Peter Chin-Hong produced by Jeanne Armstrong.

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