Doubts grow about inflatable Christmas tree's role in hospital's COVID outbreak

When 100 patients and staff at a South Bay hospital got infected with COVID-19 last December, the story ricocheted across the country. 

Early reports indicated the outbreak, which also led to one death of an emergency room employee, apparently started with an infected employee dressed in an inflatable Christmas tree costume. 

If authorities were right, it was a surreal explanation for a tragic outcome. A hospital worker wore the costume to cheer up to weary colleagues, but unintentionally also spread the virus with the battery-powered fan that kept the tree inflated, they said while discussing the outbreak.

Now, eight months later, Kaiser Permanente has indicated that that festively dressed worker, who also had unwittingly contracted the virus, is likely not the sole source of the deadly outbreak detected on Dec. 25, 2020, at its San Jose hospital, KTVU has learned. 

While the costumed employee still may have played a part in what happened, there were numerous other lapses in COVID protocols. Those findings are based on official reports and acknowledged by Kaiser in a statement to KTVU. 

The problems, found on subsequent visits, include finding employees who had been eating and talking mask-less in a breakroom and an open ventilation system, which should have been closed. 

"We understood from the outset it would be difficult to pinpoint a specific exposure leading to an outbreak," Kaiser Permanente said in a written statement. 

And after investigations by the California Department of Public Health, the Centers for Medicare and Medicaid and the Centers for Disease Control and Prevention, Kaiser said for the first time that the agencies "could not identify any single employee or patient linked to the majority of both employee or patient cases in the outbreak." 

SEE ALSO: Patient contradicts Kaiser’s claim; says she wasn't notified of Christmas COVID outbreak

Dr. John Swartzberg, a UC Berkeley public health clinical professor emeritus of infectious diseases and vaccinology, said it's pretty common not to be able to find a smoking gun for a single cause to an outbreak.

"This comes up all the time," he said.

Investigators test a variety of hypotheses, he said, and often find there are a variety of answers. 

Kaiser's response came after KTVU obtained a 21-page state health inspection conducted after the outbreak. It is not the final report and there has been no deadline on when that will be completed and released. 

However, the California Department of Health inspections show the first official glimpse at the myriad of problems investigators noticed on Jan. 15 and 28.

Among the key findings: 

  • Some staff had come into work not feeling well. The investigators suggested that a third-party screen employees coming into work; not their colleagues.
  • On one of the inspection days, two people were not masked in the radiology breakroom and were eating less than three feet apart from each other. In addition, there were multiple reports of staff being unmasked around others while eating in several locations, including nurses’ stations, break rooms and a hallway.
  • A damper in the ventilation system was found open when it should have been closed on Jan. 5. The damper was cracked open and caused the exhaust ventilation to be deficient in rooms 4 through 10. It seems as though this damper had been open since late November.
  • Some of the rapid care rooms did not meet all the requirements for airborne infection isolation rooms.
  • The hospital didn’t have the equipment or expertise to assess overall air flow patterns in the emergency department. And the quality of the air pressure and ventilation in the lobby waiting area was unclear.

SEE ALSO: Official tally of Kaiser San Jose Christmas coronavirus outbreak nears 100 cases

The Santa Clara County Health Department deferred all questions to the California Department of Health. 

The California Public Health Department has refused to answer questions either by email or phone to discuss the report or state when the final investigation into the outbreak might be complete. 

In a lengthy written response, Kaiser Permanente explained that the outbreak occurred at a time when COVID-19 case rates in Santa Clara County were at a historic high and traffic in the Emergency Department was heavy. 

SEE ALSO: San Jose Kaiser at center of Christmas Day coronavirus outbreak among California's top COVID violators

Kaiser also noted that two other state and federal licensing and certification investigations, issued in April and July, found that the hospital upheld all standards of care required by the government. 

Kaiser acknowledged that the report obtained by KTVU highlighted deficiencies at the hospital and that Kaiser has worked hard to reduce the risk of COVID by mandating the proper use of masking, configuring spaces for social distancing, forbidding breakroom gatherings, restricting visitors, screening all symptomatic patients and testing ventilation equipment. 

Swartzberg, the professor emeritus of infectious diseases, said this phenomenon, known as the Hawthorne Effect, is also quite common. Institutions, aware that they are being scrutinized, often improve because they become hypervigilant to the original problem.

"They haven't had an outbreak since, have they?" he said. 

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