The Orange County Health Care Agency (HCA) is investigating 12 cases of Legionnaires’ disease in the Anaheim area, including the death of one person, according to news reports. Nine of those sickened had visited Disneyland in September, before developing the serious respiratory illness, including one Disneyland employee.

The three individuals who took ill who had not visited the park were Orange County residents who lived or traveled in the Anaheim area. Ten of the 12 needed to be hospitalized; their ages ranged from 52 to 94 years old.

The individual who died had not visited Disneyland but had additional health problems that made them more susceptible to complications, officials said.

A common source for the illnesses have yet to be identified, but the resort voluntarily shut down two cooling towers in the theme park after elevated levels of Legionella bacteria were found in them after testing in October.

“We conducted a review and learned that two cooling towers had elevated levels of Legionella bacteria,” said Dr. Pamela Hymel, chief medical officer for Walt Disney Parks and Resorts, in a statement. “These towers were treated with chemicals that destroy the bacteria and are currently shut down.”

New Orleans Square Train Station at Disneyland

The towers are in a backstage area near the New Orleans Square Train Station, about 100 feet from areas accessible to guests.

The HCA informed Disney of the Legionnaires’ cases on Oct. 27. Hymel added that “there is no longer any known risk associated with our facilities.”

A disease on the rise in U.S.

Legionnaires’ disease is a severe type of pneumonia or lung infection and is “an emerging disease in the sense that the number of recorded cases of Legionnaires’ in the United States continues to increase,” according to Laura Cooley, MD, MPH from the Respiratory Diseases Branch of the Centers for Disease Control and Prevention (CDC).

Cooley said she believes the increase is due to an increase in the susceptibility of the population, with more and more people on immunosuppressive medications. In addition, there could be more Legionella in the environment, with warmer temperatures creating the right conditions for bacterial growth.

How do you catch Legionnaires’? 

Legionella bacteria are contracted by inhaling microscopic water droplets in the form of mist or vapor. The bacteria, which grow best in warm water, are found primarily in human-made environments. Outbreaks have been linked to a range of sources, such as:

  • cooling towers in air conditioning systems
  • decorative fountains
  • hot tubs and whirlpools
  • hot water tanks and heaters
  • large plumbing systems
  • showers and faucets
  • swimming pools.

What are the symptoms?

The symptoms of Legionnaires’ disease are similar to other forms of pneumonia or even flu, which is why so many cases go unreported. Early symptoms can include:

  • chills
  • fever, potentially 104 degrees or higher
  • headaches
  • loss of appetite
  • muscle aches.

After the first few days, symptoms can worsen to include:

  • chest pain when breathing (called pleuritic chest pain, due to inflamed lungs)
  • confusion and agitation
  • a cough, which may bring up mucus and blood
  • diarrhea (about one-third of all cases result in gastrointestinal problems)
  • nausea and vomiting
  • shortness of breath.

The incubation period – the amount of time between breathing in the bacteria and developing symptoms – is usually 2 to 10 days after exposure and can be as much as 16 days.

Who should be most concerned?

After Legionnaires’ disease has been diagnosed, hospitalization is often necessary. In the most severe cases, complications can include respiratory failure, kidney failure, septic shock, or even death.

Anyone can get the disease, but those at the greatest risk include:

  • people 50 or older
  • smokers, current or former
  • heavy drinkers of alcoholic beverages
  • people with chronic lung disease
  • people with weakened immune systems.