Kaiser Permanente has been fined $43,000 for failing to report a deadly coronavirus outbreak that may have been caused by an inflatable holiday costume worn by an unknowingly infected staffer on Christmas Day.

The number of cases linked to the outbreak at the Kaiser San Jose Emergency Department has reached 60 personnel as of Thursday, said Santa Clara County’s public health department, and one staffer has died.

County officials said the department learned of the infections through press statements issued this week by the Oakland-based hospital chain. Kaiser is responsible for the timely reporting of cases, the county said.

Irene Chavez, senior vice president and area manager with Kaiser Permanente San Jose, said in a statement Friday that “the suggestion that we are anything other than forthcoming with our reporting is inaccurate.” She said the company is reviewing the notice and will respond by the county’s deadline to appeal.

The health order violation penalty breaks down to $1,000 for each of the initial 43 cases.

The positive cases may stem from a blow-up costume worn by an infected staffer who briefly visited the department Dec. 25. Such costumes usually rely on battery-operated fans to suck air into the costume to keep its shape. COVID-19 spreads through droplets, which is why investigators are looking into the air-circulation function of the fan.

County officials say that the outbreak strain is not the new and more contagious variant first identified in the United Kingdom.