Inflatable costume not the only source of deadly Christmas COVID outbreak at Kaiser San Jose

An inflatable tree costume was not the only source of the deadly outbreak on Christmas Day at Kaiser San Jose, KTVU has learned. 

A Santa Clara County spokesperson said there were "multiple factors" behind the outbreak in the emergency room on Dec. 25, 2020, which killed one receptionist and sickened at least 100 patients and employees. 

The spokesperson also said that the California Department of Public Health and the Centers for Disease Control and Prevention got involved to determine exactly what happened, and those departments took the lead. 

But more questions than answers remain. 

Originally, all fingers pointed to a well-intentioned Kaiser staffer who showed up to cheer up her weary colleagues in an inflatable tree costume.

She unknowingly had COVID and initial reports indicated that her actions caused the outbreak because of the battery-operated, air-powered machine inside her costume. 

Santa Clara County officials vowed to get to the bottom of the outbreak and conduct contract tracing to find out if that was indeed the sole source.

Confounding to many was how the virus spread so quickly when all the staff members were supposed to be wearing masks in the ER and when the first doses of vaccinations had been administered to some Kaiser employees roughly five days or so before the outbreak. 

However, at this point, more than three months later, other than stating that the costume was not the only source of the outbreak, that is all that is publicly known. 

The Santa Clara County spokesperson said there was no more information to release and directed KTVU to track down the full report from the state and federal health departments.

After a week of emailing back and forth -- and each agency sending KTVU to find information out from another agency -- the California Department of Public Health eventually sent an email late last week saying there is nothing to report.

"DPH does not comment on ongoing investigations," the email from the communications team stated. "Investigation records become public upon completion of the investigation and the issuing of findings. Generally speaking, when an investigation, through observation, interviews, and clinical record review, determines a deficient practice (State or Federal violation) occurred, a deficiency or a citation will be issued. The facility is then required to submit a plan of correction."

The state and federal health departments would only communicate by email and refused to return phone calls seeking additional information. 

The California Department of Public Health also refused to say when a report might be issued. 

In a statement, Kaiser Permanente said the hospital cooperated with state and federal public health authorities but have not yet received the final findings.

Given the extremely high prevalence of COVID at the time, the investigation was comprehensive to ensure that "all potential sources of exposure in the emergency department were evaluated," the statement read. "There can be multiple contributing causes to a particular outbreak and we appreciate the collaboration with our public health colleagues in the effort to prevent additional infections."  

KTVU has filed public records requests to both the county, state and federal agencies in the hopes of finding out more about the "multiple" sources of the outbreak. 

Lisa Fernandez is a reporter for KTVU. Email Lisa at or call her at 510-874-0139. Or follow her on Twitter @ljfernandez