There have been a total of 15 cases reported following visits to the theme park.
Jessica Good, a spokeswoman for the Health Care Agency confirmed, Wednesday, that Disney provided updated test results to the agency showing that there was no bacteria in the cooling towers after the water in them was sanitized November 4.
Health officials are investigating possible causes of the outbreak.
Legionnaires' disease is a respiratory illness which can be contracted from inhaling microscopic water droplets in mist or vapor.
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Orange County Health Care Agency spokeswoman Jessica Good said that 11 of the 15 people infected visited popular tourist attraction.
According to the CDC, Legionella is a type of bacterium found naturally in freshwater environments. It is not spread through person-to-person contact.
The ages of those diagnosed with Legionnaires' disease range from 52 to 94. The Los Angeles Times reports that two patients have died, but neither of these visited Disneyland.
Those towers were shut down, and officials say they no longer pose a risk to park visitors. The investigation will continue so the Office of Epidemiology and Disease Surveillance staff members remain available to speak with guests who have questions, or might have been ill.