Cruise ship passengers catch legionnaires’ disease from private hot tubs

A private balcony hot tub seems like a benefit but it was a dozen travellers' downfall. Photo / 123rf

A private balcony hot tub sounds like a luxurious advantage, but for 12 cruise passengers, it was the likely source of a serious disease that hospitalised 10 people.

A dozen cruise ship travellers fell ill with legionnaires’ disease between November 2022 and July this year. The severe sicknesses occurred on two boats, but the cruise lines were not named.

Ten passengers fell so ill they were admitted to hospital.

The Centres for Disease Control and Prevention (CDC) found the source of the sickness was the private balcony hot tubs in higher-end cabins, according to a report published on October 24.

A report says the source of the sickness was the private balcony hot tubs in higher-end cabins. Photo / Supplied

Legionnaires’ disease is a severe type of pneumonia caused by the legionella bacteria. Symptoms include fever, shortness of breath, vomiting, diarrhoea, muscle aches, headaches, nausea and a cough. Left untreated Legionnaires’ disease can be fatal.

The CDC conducted months of testing and patient interviews and concluded the hot tubs were the most likely source of the sickness.

“Environmental testing revealed extensive legionella colonisation,” the report states, adding that the environment of a hot tub was perfect for the bacteria. Also, private hot tubs aren’t cleaned as regularly as public hot tubs, allowing the bacteria to fester.

The first ship’s hot tubs operated “in a manner conducive to legionella growth” for months.

This included: “Maintaining a water temperature in the legionella growth range 77-113F (25-45C) for multiple days without draining and operating with no residual disinfectant,” the report says.

Between the two ships, four were infected with legionnaires’ disease on one vessel and eight fell sick on the other. Testing on the first ship found legionella in six of the 10 available hot tubs and all eight private hot tubs of the second ship.

All private hot tubs were temporarily closed and thoroughly cleared and the cruise lines have since implemented new measures to minimise the risk of bacteria growth. These include draining tubs between uses, cleaning and disinfecting more often and filling tubs only when guests ask.

Cruise ships have developed a reputation for outbreaks, especially following the pandemic when hundreds of passengers caught the virus during sailings.

More recently, an American couple were in hospital in Denmark after one of them caught a “super-virus” during a Europe cruise in September. Six days into the trip, passenger Guy Matlock began experiencing flu-like symptoms. His condition quickly worsened and the cruise crew made the call to evacuate him to a hospital in Copenhagen, Denmark.