Norwegian Cruise Line is working with federal health officials after two guests who sailed aboard Norwegian Encore in December 2025 were later diagnosed with Legionnaires’ disease.
In a letter dated February 12, 2026, the cruise line informed guests that it is cooperating with the Centers for Disease Control and Prevention (CDC) to investigate the cases connected to passengers who traveled on the ship during a December 2025 voyage.
“We are reaching out to you to inform you that Norwegian Cruise Line (NCL) is working with the Centers for Disease Control and Prevention (CDC) to investigate two cases of Legionnaires’ disease in two passengers who traveled aboard the Norwegian Encore in December 2025,” the letter states.
The company emphasized that the source of exposure has not yet been identified.
“At this time, it is not known whether the two past guests diagnosed with Legionnaires’ disease were exposed through the ship’s water system or another source. The investigation is ongoing, and further testing will be conducted as part of this process,” the cruise line wrote.
Testing underway aboard Norwegian Encore
According to the letter, Norwegian Cruise Line has conducted testing across water systems and fixtures as part of the investigation.
“We have tested devices and fixtures that use water, including hot tubs, showers, and faucets, and thus far, all test results have been negative,” the company said.
The cruise line added that the testing is being performed in coordination with the CDC and as part of standard public health investigation procedures.
Both Norwegian Cruise Line and the CDC “are working to protect the health of the guests and crew aboard Norwegian Encore,” the letter states.
What is Legionnaires’ Disease?
Legionnaires’ disease is a serious form of pneumonia caused by Legionella bacteria. According to the CDC, people typically become infected by breathing in small droplets of water containing the bacteria. The illness is not spread from person to person.
Water systems such as hot tubs, showers, decorative fountains, cooling towers, and large plumbing systems can create the mist or vapor that allows Legionella to spread if the bacteria are present.
Symptoms usually develop between two and 14 days after exposure and commonly include cough, shortness of breath, fever, muscle aches, and headaches. Some patients may also experience gastrointestinal symptoms.
The CDC notes that individuals at higher risk include people age 50 or older, current or former smokers, those with chronic lung disease, and individuals with weakened immune systems.
The agency estimates that 8,000 to 18,000 people are hospitalized with Legionnaires’ disease in the United States each year. With prompt antibiotic treatment, most patients recover, though severe cases may require hospitalization.
Guidance for NCL Encore December 2025 guests
Norwegian advised guests who sailed on Norwegian Encore in December 2025 to monitor for symptoms for up to 14 days after their cruise ended.
“If you are currently traveling aboard Norwegian Encore or have already traveled on the ship and you experience any of the above symptoms in the 14 days after your cruise ends,” the letter advises guests to seek medical care and notify their doctor of their recent cruise.
The cruise line specifically recommends that doctors perform both “a urinary antigen test (i.e., testing your urine) and culture of sputum (i.e., testing your phlegm)” if Legionnaires’ disease is suspected.
Guests currently onboard or planning future sailings were also provided precautionary guidance, including evaluating personal risk factors and avoiding the use of tap water in respiratory devices such as CPAP or BiPAP machines. Distilled water is available onboard.
Norwegian reiterated in the letter, “Your health and safety are our top priority. We operate to the highest public health and sanitation standards across our fleet.”
At this time, there has been no confirmation that the ship’s water systems were the source of exposure, and all testing results reported so far have been negative.
Past Legionnaires’ concerns on Norwegian Epic
Norwegian Cruise Line previously issued a similar Legionnaires’ disease advisory for Norwegian Epic this past fall. In early November 2025, the company sent a notice to guests aboard the ship’s Oct. 21 – Nov. 1 Mediterranean sailing, as well as to passengers who had recently completed that voyage, after two travelers were diagnosed with Legionnaires’ disease following their cruise.
At the time, Norwegian communicated similarly, emphasizing that it was “unclear whether the diagnosed guests were exposed through the ship’s water system or another source” and that the line was working with the CDC on ongoing investigations.
About Norwegian Encore
Norwegian Encore debuted in 2019 as part of Norwegian Cruise Line’s Breakaway Plus class. The ship carries approximately 4,000 guests at double occupancy and sails itineraries to destinations including Alaska, the Caribbean, and the Panama Canal.
The vessel features attractions such as a two-level electric go-kart racetrack, laser tag arena, expansive observation lounge, specialty restaurants, and The Haven, Norwegian’s luxury suite complex.
Like all cruise ships operating from U.S. ports, Norwegian Encore follows international maritime health regulations and works with the CDC under the Vessel Sanitation Program.
The investigation remains ongoing.
