A health official testified that a cooling tower that provides mist to make Disneyland visitors comfortable was the likely source for 22 cases in a Legionnaires’ disease outbreak last year near the theme park.

Dr Matthew Zahn, of the Orange County Health Care Agency, testified on Tuesday before an appeals board judge at the California Occupational Safety and Health Administration. 

His testimony was part of an appeals case from Disneyland, which is pushing to overturn a $33,000 state fine over the outbreak, saying the source was not scientifically determined.

Zahn said tests around the time of the outbreak showed high levels of Legionella bacteria in two Disneyland cooling towers.

He said contaminated droplets likely spread to people in the park and beyond.

Upon questioning, Zahn said he could not be 100 percent certain that Disneyland was the source without additional testing. 

Three employees at the park in Anaheim, California, contracted the life-threatening condition in the last year, with two requiring hospital treatment.

Their cases were part of a county-wide outbreak that sickened more than a dozen, and killed one. 

In an effort to control the outbreaks, California health officials slapped a hefty fine on Disneyland after finding that its cooling systems were poorly maintained.

Legionnaire’s is spread via water droplets and air particles. It is caused by bacteria that can grow in man-made water systems.

Most infections are in people exposed to dirty or poorly maintained air conditioning units. People can develop pneumonia after breathing in contaminated vapor.

In sunny California, cooling systems abound, and ride-filled Disneyland is full of them.  

There has been a 450 percent increase of cases in the past two decades, according to a 2017 CDC report. 

Flu-like symptoms including fever, fatigue and muscle ache typically appear between two and 10 days of inhaling the legionella bacteria.

In most cases, the lung infection can be cured with a course of antibiotics.

However, in vulnerable populations such as the elderly or people with compromised immune systems, it can cause life-threatening complications including organ failure and septic shock.