An air-powered holiday costume is being cited as a potential cause of a COVID-19 outbreak at a California hospital, according to local media reports.

An estimated 43 staff members at Kaiser Permanente San Jose Medical Center tested positive for coronavirus between Dec. 27 and Jan. 1, the Los Angeles Times reported.

Officials are investigating whether the outbreak is tied to an inflatable costume an employee wore to celebrate the holidays.

“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,” Irene Chavez, senior vice president and area manager of Kaiser Permanente San Jose Medical Center, said in a statement to the Times.

Chavez said air-powered costumes will no longer be allowed at the facility and that the hospital is “taking steps to reinforce safety precautions among staff, including physical distancing and no gathering in break rooms, no sharing of food or beverages, and masks at all times.”

Kaiser Permanente did not immediately respond to a request for comment.

The hospital is notifying and testing any individuals who may have been exposed to the virus and is asking those who may be infected to stay home. Kaiser said it plans to test all emergency department workers and that its emergency department is being cleaned.

There are currently more than 2 million coronavirus cases in California. Over 26,000 people in the state have died of the virus.