The Orange County Health Agency said 12 cases of the bacteria-caused illness were found three weeks ago, and nine were people who visited the park in September, the Los Angeles Times reported.
Disneyland shut down two of their cooling towers after multiple cases of Legionnaires' disease was found in park visitors.
The Walt Disney Company is the parent company of Walt Disney Parks and Resorts and this station.
Twelve cases of Legionnaires' disease are being investigated by OC health experts, among those are 9 patients who visited the park in September, according to the OC Register.
On November 3, Disney reported that routine testing had detected elevated levels of Legionella in two cooling towers a month earlier, and they were disinfected, according to the health agency. Neither Disney nor the contractor would have been aware of the human cases at that time. Disney independently chose to take the towers out of operation the day before, Good said. They remain out of service, pending inspection by local authorities. The victims' ages range from 52 to 94. One person, who had not visited Disneyland, died from the disease.
Although the Health Care Agency sent alerts to medical providers and other public health departments to help identify other people who have contracted Legionnaire's disease, the agency issued no public press releases or statements because "there was no known, ongoing risk associated with this event", Good said.
Legionnaires disease is caused by the Legionella bacteria and can cause potentially fatal respiratory illness and pneumonia. Typical sources are improperly sanitized spas; indoor and outdoor fountains, showers, and cooling towers (which emit water vapor into the air) used as part of air conditioning systems in large spaces such as hospitals, hotels, entertainment venues, etc.
People generally contract the disease two days after exposure and usually can be treated with antibiotics, though the CDC said one in 10 people die from the infection. Infected persons often have pneumonia and may need to be hospitalized.
Persons with legionellosis are not infectious; the infection is not spread from person to person.
People ages 50 or older, or those with weakened immune systems, are most at risk for the illness.