Royal Caribbean is warning passengers on one of its ships that two past passengers later were sickened by Legionnaires' disease.
A guest on Symphony of the Seas received a letter from the cruise line "in an abundance of caution" to inform them of a possibility to be aware of, and the preventative measures the cruise line is taking.
To be clear, the guests were not diagnosed onboard the cruise ship, nor has there been a recognized outbreak linked to a specific sailing.
Reddit user b0sscrab posted a copy of a letter distributed to passengers, after the the Centers for Disease Control and Prevention warned Royal Caribbean about the cases.
The CDC said two passengers were later diagnosed with Legionella. One had sailed on Symphony of the Seas in October and the other in December.
"We are reaching out for your awareness, as the CDC has advised that while they are unsure where exposed, two guests who sailed on Symphony of the Seas (one in October and one in December), were later diagnosed with Legionella," the letter said.
Royal Caribbean was quick to note there is no evidence that the infection occurred on the ship.
As soon as the cruise line was notified, extra sanitation protocols were implemented aboard Symphony of the Seas, including extra cleaning of vulnerable surfaces and equipment as needed, and changes to operational protocols to limit any potential spread, "While this does not imply or confirm that they contracted this onboard our ship, as a precautionary measure, we implemented heightened sanitation protocols and followed all CDC guidance."
No other information was shared related to who the people are, or other details.
Symphony of the Seas is one of the biggest cruise ships in the world. It can carry 5,518 passengers at double occupancy and is 228,081 gross tons spread over 18 decks.
Royal Caribbean is urging any passengers who experience symptoms associated with Legionnaires’ Disease after sailing aboard Symphony of the Seas to seek medical attention and alert medical authorities to their recent travel.
No one actually sick on a cruise ship
It's important to reiterate that no one on Symphony of the Seas is actually sick with Legionella, nor is there any certainty that the two people actually caught it on the ship.
The CDC investigates this particular bacteria to better identify its sources to prevent the spreading of it. As such, they alerted Royal Caribbean to the two cases because both people were on the same cruise ship.
It's possible the people had Legionella before they ever stepped foot onboard a cruise ship, or equally possible they contracted it after the cruise somewhere else.
A proper Legionella diagnosis can take some time to properly determine. The incubation period is typically 2-14 days for Legionella.
There's no record of any confirmed disease aboard Symphony of the Seas that has been reported to the CDC.
How it spreads
Legionella is not easily spread from person to person, but it's still something that could occur because cruise ships have pools and hot tubs.
According to Royal Caribbean, Legionella is not contagious from person to person. It is contracted by inhaling water droplets from a source containing the bacteria, which can be found throughout the world in any environment containing water - ponds, lakes, rivers, and streams, as well as municipal water systems, fountains, and whirlpools.
Moreover, most healthy people exposed to Legionella do not get sick.
Symptoms include cough, shortness of breath, fever, muscle aches, and headaches. It's often confused with pneumonia.
Legionnaires' on cruise ships
Legionnaires' is a rare condition to begin with, but it has happened on cruise ships in the past.
During November 2022–June 2024, the CDC was notified of 12 cases of Legionnaires disease among travelers on two cruise ships. The CDC did not disclose the cruise line names or ships.
According to the CDC, their investigation revealed private hot tubs on selected cabin balconies were the most likely exposure source.
Some cruise ship cabin suites have a hot tub on the balcony, which is for the exclusive use of the guests staying in that cabin. The CDC says, "private hot tubs on cruise ships are not subject to the same maintenance requirements as are public hot tubs in common areas."
They recommended to cruise lines modification of the operation and maintenance of these devices by removing the heating elements, draining water between uses, and increasing the frequency of hyperchlorination and cleaning.
