A recent scientific study examined how often passengers and crew on cruise ships wash or disinfect their hands – and whether current practices are sufficient to prevent the spread of infection. The findings suggest that, despite clear risks and established hygiene measures in certain areas, hand hygiene on board remains inconsistent. At the same time, the study offers practical insights into how infection prevention at sea could be improved.
Cruise ships present a particular challenge for infection control. They are relatively small, densely populated environments where large numbers of people share cabins, restaurants, lifts, handrails, and other frequently touched surfaces over extended periods of time. According to the Vessel Sanitation Program of the U.S. Centers for Disease Control and Prevention (CDC), 23 outbreaks were recorded on cruise ships in 2025 alone, most of them caused by noroviruses, which can lead to severe gastrointestinal illness. In March 2025, for example, 266 of the 2,538 passengers aboard the Queen Mary 2 were infected during a single outbreak.
Hand Hygiene as the First Line of Defence
Hand hygiene, including both handwashing and hand disinfection, remains the most effective single measure for preventing infections on cruise ships. While this is widely acknowledged, far less is known about how consistently these measures are applied in practice outside of clearly regulated settings.
This question was explored in a recently published European study led by Szava Bansaghi and Jörn Klein. The research was conducted on the Celestyal Olympia, a medium-sized cruise ship accommodating 1,664 passengers and 540 crew members. Using hand hygiene product consumption data and observational methods, the researchers assessed how frequently hand hygiene was actually performed and evaluated several interventions aimed at improving compliance.
The results present a clear picture. On average, each person on board used 7.6 doses of soap and only 1.6 doses of hand disinfectant per day, indicating that hand hygiene frequency was low relative to the number of opportunities throughout the day. Even a single restaurant visit creates at least two indications for hand disinfection per meal, and hygienic hand disinfection is also recommended when embarking and disembarking the ship.
Also, more than 70% of all observed hand disinfections took place before entering restaurant areas. This suggests that many passengers primarily associate hand hygiene with food safety rather than with broader infection prevention.
While food hygiene is tightly controlled, passenger hand hygiene remains under-specified and inconsistently promoted.
An observation from the study emerged during interactions with passengers. When researchers explained that the study aimed to improve hygiene on board, most people immediately assumed the focus was food hygiene. This response reflects the fact that food hygiene on cruise ships is well regulated, clearly communicated, and routinely monitored – and as a result, standards in areas such as kitchens were generally well maintained.
In contrast, passenger hand hygiene outside food settings receives far less attention and is guided by fewer concrete recommendations. The study suggests that cruise operators tend to comply with hygiene regulations when clear guidelines exist, but struggle to address areas where expectations are less defined. This highlights a gap in current infection prevention strategies.
Behaviour Matters, But the Setting Matters More
Compliance data from the study reveals distinct behavioural patterns among passengers. A small minority, less than 5%, consistently performed hand hygiene under all circumstances, actively seeking out dispensers or carrying their own hand rub. Another small group, fewer than 10%, appeared strongly resistant to performing hand hygiene at all.
For the vast majority of passengers, however, hand hygiene was simply not a priority. These individuals would disinfect their hands if a dispenser was conveniently placed, clearly visible, or if they were directly prompted to do so. They were unlikely to make any additional effort on their own. This finding underscores a key message of the study: hand hygiene behaviour is largely shaped by the environment, not by personal conviction or awareness alone.
Why Simple Interventions Fall Short
The study also demonstrates that there is no quick or simple fix. Measures such as occasional surface disinfection, informational leaflets placed in cabins, or unattended monitoring devices in public areas were not sufficient to meaningfully improve hand hygiene behaviour on their own. Even crew training, while effective at improving theoretical knowledge, did not translate into measurable behavioural change.
Monitoring of hand hygiene technique revealed further challenges. When first assessed, staff members missed an average of 9.6% of hand surface areas during hand rubbing, highlighting the difficulty of achieving correct technique without sustained support. The researchers also note that monitoring technologies are only effective if crew members can realistically use them during their shifts, a constraint that is often underestimated.
Language barriers and the diverse backgrounds of both passengers and crew further complicate communication and training efforts, limiting the effectiveness of written materials or generic instructions.
Designing for Compliance
One of the clearest conclusions from the study is that placement and context are decisive. Hand sanitizer dispensers were used more frequently when they were:
- clearly visible from a distance,
- placed in areas where people moved slowly and were not under time pressure, and
- integrated into natural walking paths, avoiding extra steps or detours.
The findings also suggest that improving hand hygiene on cruise ships requires active human involvement. Assigning crew members to actively promote and facilitate hand hygiene may be essential, as passive measures alone are unlikely to change behaviour.
Closing Reflection
Taken together, the study shows that while cruise ships have made strong progress in regulated areas such as food hygiene, passenger hand hygiene remains an underdeveloped aspect of infection prevention. Most passengers are neither strongly for nor against hand hygiene – they simply respond to how easy, visible, and socially expected it is.
Clearer guidelines, better environmental design, active promotion, and culturally sensitive communication could collectively raise hygiene standards and reduce the risk of outbreaks at sea.
The full study, “Improving Hand Hygiene in Cruise Ships: An Intervention Study,” is freely available on the Open Research Europe website.
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