According to Good, during the week of October 20-26 the Centers for Disease Control and Prevention notified Health Care Agency staff of the Legionnaire's disease cases that occurred in September.
The discovery has led to the shutdown of two cooling towers at Disneyland, which nine of the 12 people visited during September.
The Los Angeles Times reported that 12 cases of the bacteria-caused illness were discovered about three weeks ago among people who had visited the park in Anaheim, Calif. One of the 12, who had other health issues and did not visit Disneyland, died. That person had not visited Disneyland.
Legionnaires' is a airborne disease which causes a form of pneumonia especially unsafe to people 50 years or older.
Disneyland has shut down two cooling towers at its theme park after a dozen cases, including one death, from Legionnaire's disease - a serious respiratory illness caused by the Legionella bacteria - were reported in Anaheim.
The towers are in a backstage area near the New Orleans Square Train Station, each more than 100 feet from areas accessible to guests, a Disneyland Resort spokeswoman said. A Disneyland employee is among those who got sick.
According to the OCHCA, the Legionnaire's disease exposure period ranged from September 12 to September 27, Hymel said, adding that Disney thoroughly reviewed all regular water testing for the resort, "including work performed by contracted third-party experts", and "implemented additional redundant testing of other cooling towers on our property". "These towers were treated with chemicals that destroy the bacteria and are now shut down".
"Because of the existence of human illness and the inability to assure the cooling towers are clear of Legionella bacteria until test results are known, the County of Orange Health Officer issued a Health Officer's Order on 11/8/17 requiring that Disney take the towers out of service until they are verified to be free from contamination, at which time the Health Officer will lift the order Disney independently made the determination to take the towers out of operation on 11/7/17, after meeting with HCA staff but prior to the order".
Legionnaires' disease is a progressive pneumonia with a 2-10 day incubation period. Outbreaks are often traced to hot tubs, decorative fountains, cooling towers and large air-conditioning systems that emit water vapor into the air. It is not contagious from person to person. Most at risk are people over 50 with weakened immune systems or chronic lung diseases.
There have been 55 reports of Legionella disease in Orange County residents through October of 2017; 53 were reported for the entire year of 2016; and 33 in 2015, according to Good.