A health official testified that Disneyland’s mist-infused cooling towers that refresh visitors is the source of 22 cases of Legionnaires’ disease. Disneyland officials disputed the source linked to the theme park in 2017.  The California Occupational Safety and Health Administration fined Disneyland $33,000 last March for failing to properly clean cooling equipment linked to the outbreak and other related violations. Disneyland is appealing the citation.

Disneyland spokeswoman Suzi Brown denied the accusations regarding the outbreak in a statement released earlier this year. “We strongly object to Cal-OSHA’s allegation that our cooling towers caused any illness since the source of the outbreak has never been scientifically determined,” said Brown.

Epidemiologist Dr. Matthew Zahn of the Orange County Health Care Agency testified before a Cal-OSHA appeals board judge Tuesday, saying though the agency hasn’t officially concluded Disneyland as the source of the outbreak, cooling towers are the most common source of Legionnaires.

Majority of those who fell ill visited the park in the fall of 2017. Disneyland  denied it was the source, citing three infected people who were in Anaheim but not at Disneyland. According to Dr. Zahn, health workers visited the nursing homes where those three individulas lived and determined there were no likely sources of the Legionella bacteria there.

In addition, he stated more testing is necessary to confirm the source, though one one Disneyland cooling tower showed very high levels of Legionella bacteria when people reported the illness last year. After the tower was sanitized, the infections seem to cease, he added.

“Most likely those cases were related to a common exposure,” Zahn said. “Cooling tower No. 4 was the most likely source of exposure.”