As part of its enforcement activities, the Food and Drug Administration sends warning letters to entities under its jurisdiction. Some letters are not posted for public view until weeks or months after they are sent. Business owners have 15 days to respond to FDA warning letters. Warning letters often are not issued until a company has been given months to years to correct problems.

American Cruise Lines
Guilford, CT

American Cruise Lines is on notice from the Food and Drug Administration (FDA) after an inspection of their American Star and American Heritage vessels. According to the warning letter, the FDA continues to have concerns with the potential exposure of passengers and crew members to Legionella onboard American Cruise Lines’ vessels.

In Jan. 24, 2023, warning letter, the FDA described an April 30 through June 17, 2022, an inspection of American Cruise Lines’ American Star and American Heritage vessels.

The warning letter includes information about failed water tests for a sink in the galley and hand-washing sinks for wait staff. The FDA also found that disinfection was ineffective.

The investigation and inspections were initiated by FDA after three passengers who traveled in April 2021, September 2021, and September-October 2021 aboard the vessels were diagnosed with Legionnaires’ disease.

Legionella bacteria can cause a serious type of pneumonia (lung infection) called Legionnaires’ disease. Legionella bacteria can also cause a less serious illness called Pontiac fever.

The number of cases reported to the CDC has been on the rise since 2000. Health departments reported nearly 10,000 cases of Legionnaires’ disease in the United States in 2018. However, because Legionnaires’ disease is likely underdiagnosed, this number may underestimate the true incidence. once exposed to the bacteria, disease symptoms will typically appear in two to 10 days. 

At higher risk are people who have had an organ transplant, older people, heavy smokers, anyone with a weakened immune system, those who indulge frequently in alcoholic beverages, and those with underlying medical issues or who are on drug therapies. Legionnaires’ is not spread by person-to-person contact and fewer than five people in every 100 exposed to contaminated water will develop symptoms. Antibiotics are usually used to treat it. Early treatment is most effective.

Legionnaires’ disease is caused by a type of bacteria usually found in water. It is contracted when the mist or vapor containing the bacteria is breathed in. Hot tubs, fountains, and air conditioning units often help create conditions for it.

American Cruise Lines and FDA were notified by the Centers for Disease Control and Prevention (CDC) of the first confirmed case of Legionnaires’ disease at the end of April 2021 (American Heritage), the second at the beginning of November 2021 (American Star), and the third at the end of November 2021 (American Heritage).

During the FDA inspections, FDA investigators collected biofilm swabs and potable water samples from their American Star and American Heritage vessels. Laboratory Analysis of those samples identified Legionella pneumophilia and Legionella spp. in the potable water system of the vessels.

FDA investigators also observed insanitary conditions related to the potable water systems onboard the vessels. At the conclusion of the inspections, the FDA investigators issued a Form FDA 483, Inspectional Observations, to both vessels. 

Some of the significant violations are as follows:

The FDA determined that the potable water onboard the American Star and American Heritage vessels is adulterated, in that it has been prepared, packed, or held under insanitary conditions wherby it may have been contaminated with filth or rendered injurious to health.

American Star
Presence of Legionella onboard the Vessel

On April 30, 2022, FDA investigators collected 10 biofilm swabs and 14 bulk one-liter potable water samples from various locations on the vessel. The Maryland Department of Health laboratory recovered Legionella from:

Biofilm Swabs with 60 percent of samples positive:

• 5 Showerhead pipes in passenger cabins

• Wait for station hand sink faucet aerator in the galley

Potable Water with 93 percent of samples positive:

• 7 Showerhead pipes in passenger cabins

• 2 Showerhead pipes in crew rooms

• Wait for station hand sink faucet aerator in the galley

• Galley prep sink faucet aerator

• Potable water holding tank

• Post pump (redacted) hot water return spigot

Post-Notification Actions
The firm did not change its procedures regarding potable water after CDC notified it on Nov. 5, 2021, that a passenger was diagnosed with Legionnaires’ disease. For example, the firm did not change its procedures for flushing or disinfection and did not perform environmental sampling. Subsequently, after FDA notified them of its detection of Legionella onboard their vessel (June 2, 2022), the firm disinfected the vessel’s potable water system (redacted). On June 4, 2022, the firm provided a letter to each passenger notifying them of the presence of Legionella in the potable water system onboard the vessel and the mitigation steps they had taken. Also, they provided a letter notifying passengers who were onboard the vessel previously from May 3, 2022, to June 4, 2022.

During the week of (redacted), the firm conducted water sampling using a field test kit. On June 24, 2022, FDA expressed concerns to the firm regarding the use of this field test kit and ending passenger notifications based on this testing because their testing was limited to Legionella pneumophilia serogroup 1 and did not include species identified as present on the vessel by FDA’s testing. In addition, FDA expressed concerns with the sensitivity, detection limit, and size of the water samples collected for the field test kit. On June 28, 2022, they shared additional sample collection results with FDA, separate from the field test kit, that was analyzed in a laboratory.

FDA expressed concerns with these laboratory results not being representative nor sufficient to determine whether Legionella is still present and their use of these and the field test kit results to justify ending notification of passengers. Specifically, FDA collected 14 bulk water and 10 biofilm swab samples; they collected (redacted) bulk water and (redacted) biofilm swab samples for the laboratory tests. Thirteen of fourteen (92.86%) of FDA’s bulk water samples and 6 of 10 (60%) of FDA’s biofilm swab samples were positive for Legionella. The firm did not evaluate most of the bulk water and biofilm swab locations that were positive from the FDA’s sampling. In addition, one of the biofilm swabs they took was from a (redacted) that was negative from FDA’s sampling.

The firm restarted passenger notifications and provided them from July 9, 2022, to July 30, 2022. On (redacted), the firm collected additional samples and notified FDA of negative results on Aug. 16, 2022. On Sept. 20, 2022, FDA submitted additional follow-up questions regarding the vessel’s sampling process, laboratory results, and future disinfection process. 

Vessel Inspection
During the inspection, the following unsanitary conditions and practices were observed: Failure to Monitor Potable Water Parameters.

The firm did not monitor potable water parameters, such as free or total chlorine residual, temperature, and pH on the vessel when docked and not in operation or while in operation. Sample collection of biofilm swabs and potable water samples by FDA investigators on April 30, 2022, documented the following:

Free chlorine and total chlorine residual were measured at 1.5 ppm and 2 ppm, respectively, in the potable water holding tanks wher water is initially stored in the vessel. After the potable water traveled from the potable water holding tanks wher initially stored to distal piping onboard the vessel such as showerheads, seven of 10 biofilm swabs and 10 of 14 bulk potable water samples had no free or total chlorine residual. The dissipation of chlorine residual from the potable water holding tanks to distal piping indicates that conditions, such as the presence of biofilm or planktonic microorganisms, led to the immediate use of the residual chlorine in the potable water system on the vessel.

Eight of 10 biofilm swabs from showerhead pipes and a wait station hand sink faucet aerator and 11 of 14 bulk potable water samples had temperature ranges from 83.1 degrees F – 112.6 degrees F, which is ideal for Legionella growth.

pH was measured between 5-7 for biofilm swabs and bulk potable water samples. pH level is important to consider as it impacts the effectiveness of the chlorine residual. pH can also cause potential corrosion of potable water pipes when not carefully monitored. Unlike temperature, it is not possible to set a single target value for pH since there are several factors that a water operator would use to determine the target. The efficacy of chlorination is affected by many factors, one of which is pH. The efficacy of chlorine declines as pH increases >7, with a significant loss of efficacy at pH >8. While the optimum pH range for systems treated with monochloramine is 7.5 to 9.0, it is important to know how their source water is treated to determine the appropriate pH range for each of their systems.

By monitoring these parameters, the firm can ensure that the vessel’s potable water system is operating in a way to minimize hazardous conditions that could encourage Legionella and other waterborne pathogens to grow. If they find that one or more of these parameters is not being met, the next step would be to take corrective actions to get conditions back within an acceptable range for the vessel’s potable water system.

While the vessel (was redacted), the potable water system was flushed and filled (redacted). Stagnant or standing water in a potable water system can increase the risk for the growth and spread of Legionella and other biofilm-associated bacteria. When water is stagnant, hot water temperatures can decrease to the Legionella growth range. Stagnant water can also lead to low or undetectable levels of disinfectant, such as chlorine. Therefore, it is also essential for them to monitor parameters such as free or total chlorine residual, temperatures, and pH during water stagnation to determine whether their frequency of flushing and filling is adequate to minimize hazardous conditions that could encourage biofilm development and Legionella (and other waterborne pathogens) to grow.

Failure to Monitor Disinfection Effectiveness

According to the Port Engineer, cabin outlets were allowed to run for approximately (redacted) during (redacted) disinfection when the vessel (redacted). No specific sequence was given to crew in the galley, crew quarters, and various other cabins for turning on the faucets, taps, showerheads, and other locations to run the disinfectant.

During the disinfection, the firm did not measure the disinfectant level, pH, and temperature to verify that an adequate amount of the disinfectant at an appropriate pH and temperature reached the proximal, medial, and distal faucets and showerheads and other areas that are part of the potable water system. Without verifying the disinfectant level, pH, and temperature during disinfection in a complex potable water system such as a vessel they cannot know whether the disinfection was effective in various areas of the potable water system. In addition, the firm did not perform environmental sampling of the potable water system, i.e., testing biofilm swabs and bulk potable water for microorganisms such as Legionella, to validate the effectiveness of the disinfection and their frequency of disinfection ((redacted)).

American Heritage

Presence of Legionella onboard the Vessel

On June 15, 2022, FDA investigators collected 24 biofilm swabs and 29 bulk one-liter potable water samples from various locations on their vessels. The Maryland Department of Health laboratory recovered Legionella from:

Biofilm Swabs with 8 percent of samples positive:

• 1 Showerhead pipe in a passenger cabin

• 1 Bathroom faucet aerator in a passenger cabin

Potable Water with 7 percent of samples positive

• 1 Showerhead pipe in a passenger cabin

• 1 Bathroom faucet aerator in a passenger cabin

Post-Notification Actions
On April 30, 2021, and Nov. 30, 2021, the firm was notified by CDC of confirmed cases of Legionnaires’ disease. After being notified of two confirmed cases of Legionnaires’ disease that traveled onboard the American Heritage, the firm did not change its procedures for flushing or disinfection and did not perform potable water or environmental sampling. On (redacted), they disinfected the vessel’s potable water system. Subsequently, on June 15, 2022, FDA collected water and biofilm samples from the vessel. On July 14, 2022, FDA notified them of the positive findings regarding Legionella onboard the vessel. Subsequently, they provided notifications to each passenger on the voyage departing July 16, 2022, of the presence of Legionella in the potable water system. The firm also provided notifications to passengers onboard the vessel previously that departed on June 18, 2022, June 25, 2022, July 2, 2022, and July 9, 2022.

FDA’s positive samples were collected after their (redacted) disinfection and thus show that their disinfection was not fully effective. The passenger cabin wher FDA detected Legionella in the showerhead pipe and bathroom faucet aerator is very distal to the potable water holding tanks and water heaters; distal locations are wher routine chlorine levels would be lowest and hyperchlorination would be least effective. The firm subsequently disinfected the showerhead pipe and sink faucet aerator in the positive passenger cabin and installed a (redacted) on the showerhead in that cabin to decrease the risk of exposure to Legionella. However, they have not performed any additional disinfection of the potable water system since (redacted), which is prior to FDA’s collection of positive samples.

The FDA continues to have concerns with the potential exposure of passengers and crew members to Legionella onboard the American Heritage. The FDA notes that they have chosen not to do remediation and disinfect the potable water system after notification that the showerhead pipe and sink faucet aerator in a passenger cabin had biofilm swabs and potable water samples that tested positive for Legionella. FDA’s sampling results demonstrate that the disinfection performed on (redacted), prior to the initial representative sampling by FDA, was not sufficient to address Legionella onboard the American Heritage. The device on the showerhead in the passenger cabin that assists in limiting exposure from showering does not address the overall concern that Legionella may be present in the vessel’s potable water system. Also, although the firm indicated that they disinfected the sink faucet aerator, they have not addressed the Legionella found in the biofilms from the pipe and in the sink faucet aerator of the passenger cabin. When Legionella is associated with protozoa, including amoebae (as can be the case with a biofilm present), it can be more resistant to disinfection such as the use of chlorine. The firm needs to ensure that the disinfection procedures they use are effective for the removal of biofilms associated with Legionella.

Vessel Inspection
During the inspection, the following unsanitary conditions and practices were observed:

Failure to Monitor Potable Water Parameters

The firm did not monitor the parameters of the potable water, such as free or total chlorine residual, temperatures, and pH on the vessel when docked and not in operation or while in operation.

Sample collection of biofilm swabs and potable water samples by FDA investigators on June 15, 2022, documented the following:

19 of 24 biofilm swabs and 24 of 29 bulk potable water samples had no free or total chlorine residual. Lack of free and/or total chlorine indicates that conditions, such as the presence of biofilm or planktonic microorganisms may have led to the immediate use of this residual chlorine in the potable water system onboard the vessel.

22 of 24 biofilm swabs and 26 of 29 bulk potable water samples had temperature ranges from 81.3 degrees F – 113 degrees F, which is ideal for potential Legionella growth.

pH was measured between 6-7 for biofilm swabs and bulk potable water samples. pH level is important to consider as it impacts the effectiveness of the chlorine residual. pH can also cause potential corrosion of potable water pipes when not carefully monitored. Unlike temperature, it is not possible to set a single target value for pH since there are several factors that a water operator would use to determine the target. The efficacy of chlorination is affected by many factors, one of which is pH. The efficacy of chlorine declines as pH increases >7, with a significant loss of efficacy at pH >8. While the optimum pH range for systems treated with monochloramine is 7.5 to 9.0, it is important to know how their source water is treated to determine the appropriate pH range for each of their systems.

By monitoring these parameters, the firm can ensure that the vessel’s potable water system is operating in a way to minimize hazardous conditions that could encourage Legionella and other waterborne pathogens to grow. If they find that one or more of these parameters (e.g., pH, free or total chlorine, temperature) is not being met, the next step would be to take corrective actions to get conditions back to within an acceptable range for the vessel’s potable water system.

While the vessel was (redacted), the potable water system was flushed and filled (redacted). Stagnant or standing water in a potable water system can increase the risk for the growth and spread of Legionella and other biofilm-associated bacteria. When water is stagnant, hot water temperatures can decrease to the Legionella growth range. Stagnant water can also lead to low or undetectable levels of disinfectant, such as chlorine. Therefore, it is essential for them to monitor parameters such as free or total chlorine residual, temperatures, and pH during water stagnation to determine whether their frequency of flushing and filling is adequate to minimize hazardous conditions that could encourage biofilm development and Legionella (and other waterborne pathogens) to grow.

Failure to Monitor Disinfection Effectiveness

The Engineering Manager stated that disinfection was performed once from March 2021 to March 2022 and (redacted) during (redacted) from (redacted). During disinfection, cabin outlets were allowed to run for approximately (redacted). No specific sequence was given to the crew in the galley, crew quarters, and various other cabins for turning on the faucets, taps, showerheads, and other locations to run the disinfectant.

The disinfection consisted of forcing the potable water tanks to a (redacted) concentration of (redacted)ppm for (redacted) and then flushing (redacted) shower heads and sinks on the vessel. Afterward, the (redacted) was adjusted down to (redacted)ppm to make the water potable again. During the disinfection, the firm did not measure the disinfectant level, pH, and temperature to verify that an adequate amount of the disinfectant at an appropriate pH and temperature reached the proximal, medial, and distal faucets and showerheads and other areas that are part of the potable water system.

Further, the disinfection they performed on (redacted), was not sufficient as demonstrated by the FDA’s sampling results from June 15, 2022, that showed the presence of Legionella in a passenger cabin. Lack of verification of the disinfectant, pH, and temperature during disinfection in a complex potable water system such as a vessel prevents them from knowing whether the disinfection was effective in various areas of the potable water system. In addition, the firm did not sample the potable water system for microorganisms such as Legionella to verify the effectiveness of the disinfection.

Finally, the FDA notes that the firm has other vessels in its fleet. Although the FDA is not aware of a case of Legionnaires’ disease being associated with any of those vessels, based on their practices on the American Star and American Heritage, FDA has concerns about the potable water on their other vessels. Specifically, if adequate practices are not followed regarding potable water on those vessels, there is a potential for waterborne illnesses to occur. It would not be appropriate to wait until there is a confirmed case of Legionnaires’ disease to address the water practices onboard those other vessels. As a reminder, people at increased risk of Legionnaire’s disease include those 50 years of age or older and we understand that the majority of the passengers onboard the American Star and American Heritage exceed this age.

The full warning letter can be viewed here.