Another person is dead, and three additional cases been linked to the Anaheim Legionnaires’ disease outbreak, it was announced Wednesday by the Orange County Health Care Agency (HCA).

Two of the three new cases involved individuals who visited Disneyland. Of the 15 cases, 11 involved people who visited Disneyland in September, including one who worked there.

Thirteen of the 15 patients were hospitalized and the two who died both had underlying health problems that made them more susceptible to complications, Neither individual who died visited Disneyland.

No additional information was made available on the two individuals who passed away.

Cooling towers at Disneyland were shut down after Dr. Eric Handler, the county’s Health Officer, issued an order Nov. 8 requiring Disney to take the towers out of service until the park can ensure they are free of contamination. Elevated levels of Legionella bacteria, which is the bacteria that causes Legionnaires’ disease, were found in them after testing in October.

Recent water samples collected Nov. 2 and Nov. 6 were negative for the bacteria, according to Disneyland officials. The water in the towers was sanitized Nov. 4.

“Negative results mean that the towers do not pose a current ongoing risk for transmission of Legionella,” HCA spokesperson Jessica Good said, adding that the agency is working with Disney on procedures to bring the towers back into operation.

Those procedures include making sure cleaning and sanitation are done according to guidelines set forth by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, and the Cooling Technology Institute. Disney must also provide a plan to clean, maintain and monitor all of its cooling towers for bacteria.

The cooling towers will reopen after all the criteria have been satisfied.

Good said the majority of patients having visited Disneyland “indicates a pattern but does not identify that specific location as the common source of infection for all cases.”

Health officials continue to search for the source, according to Good. They’re visiting hotels, motels, and businesses that aren’t associated with the Disneyland Resort along the Harbor Boulevard corridor to see if they can find any connection to the illnesses.

The 15 cases were reported to the HCA between Sept. 27 and Nov. 15 and involved individuals whose ages ranged from 52 to 94 years old. All were infected before the cooling towers were shut down.

Cooling towers hot spots for Legionella

The Legionella bacteria is endemic in cooling towers throughout the United States, according to a recent study by the Centers for Disease Control and Prevention (CDC).

The CDC tested water from 196 cooling towers in eight of nine continental U.S. climate regions, and 84 percent returned positive results for Legionella DNA, meaning the bacteria were either present or had been present at some point. Overall, investigators found live Legionella bacteria in 79 cooling towers – half of which had more than one type of Legionella – in most regions of the country.

The CDC study is the first to illustrate how prevalent Legionella may be in cooling towers, which are known to be a prime culprit in Legionnaires’ disease outbreaks. In two recent and well-publicized outbreaks:

  • Between August and September in 2016, one person died and 23 people were sickened in a Hopkins, MN, outbreak. Officials identified a Citrus Systems, Inc., cooling tower as the source.
  • In 2015, contaminated cooling towers were responsible for the deaths of 12 and more than 120 others becoming infected with Legionnaires’ disease in the South Bronx, NY.

The CDC had previously announced a 286 percent increase in the number of reported Legionnaires’ cases in the U.S. between 2000 and 2014.