Cruise Ships and Health Risks
Cruises can be a source of concern for various reasons. A vivid memory from the early COVID-19 pandemic is the Diamond Princess, which at one point represented about 50% of all confirmed infections.
More recently, the MV Hondius made headlines due to a hantavirus outbreak among its passengers. While hantavirus isn’t likely to cause a pandemic, it presents significant challenges for those on board since its long incubation period—in some instances up to six weeks—means passengers need to be isolated for an extended period. This isn’t the only troubling news from the cruise industry; a norovirus outbreak on a ship named Ambition recently afflicted many passengers shortly after their journey began.
As an epidemiologist, I often find myself asked if I would take a cruise. With the ongoing outbreaks of infectious diseases associated with cruises, people are curious about the risks of illness on these floating holidays. So, do I think cruises are a safe choice from a health perspective? The answer is… well, it gets a bit tricky.
Theoretically speaking, cruises present ideal environments for diseases to spread. A study conducted in 2022 equipped cruise participants with contact-tracing devices to assess how many close interactions they had daily, revealing that an average passenger made about 20 unique close contacts each day, notwithstanding attempts to mitigate COVID-19 risks on board. This is a considerable opportunity for infections to transfer.
Nevertheless, evidence on whether infections are actually more prevalent on cruises compared to land outings is somewhat scant. It’s possible that more social individuals choose to cruise or that holiday scenarios generally allow for more contact with others. High-profile outbreaks on cruises might get media attention, even if the pathogens involved aren’t new. For instance, in response to the norovirus outbreak, French authorities kept passengers aboard, leaving them stranded with illness—definitely a scene that garners attention. There are also significant scientific accounts of outbreaks; for example, one notable gastroenteritis case helped refine contact tracing methods.
As for accurate indications of illness prevalence, studies often focus on passengers who sought medical help while cruising. A study from a 105-day world cruise indicated that around 20% of passengers consulted the ship’s doctor for infections, mostly respiratory or gastrointestinal. In reality, if this rate reflects actual illness, it isn’t particularly alarming—typically, adults experience more than one respiratory infection annually, translating to less than one infection per year while cruising.
However, these studies have their limitations. They generally miss out on those who might not seek help unless feeling severely unwell. Many cruise lines enforce isolation regulations for those who fall ill, which might deter passengers from seeking treatment, making them wait until they’re quite miserable to do so.
The case of the Diamond Princess serves as an essential example. During that outbreak, 20% of passengers tested positive for COVID-19, but estimates suggest the true percentage could have been higher—possibly around 30%. And, of course, that’s just one disease, amidst all the others passengers might carry on board.
In short, it’s clear that cruise ships likely present a noteworthy risk for infections, but pinning down the exact nature of that risk remains complex. Yes, we know diseases can spread rapidly among cruise-goers, but determining how much more so than in everyday life is tricky.
So, given all this information, would I personally go on a cruise? It’s a difficult question. Perhaps…
Here’s my thought process: there’s a decent chance you’ll get sick on a cruise compared to other vacation types, like a quiet beach getaway. However, as the parent of young kids, I’ve come to accept a certain level of sickness in our household—we average about six illnesses a year. I find great value in the convenience a cruise offers. I don’t have to plan meals or activities; it’s all laid out. Therefore, my family must weigh the potential risk of illness against the risk of us going a little stir-crazy with alternative vacation plans. Older adults might want to consider their vulnerability to infections on cruises. Still, they might also enjoy the ease of travel without multiple flights or long drives. There are certainly pros to cruising.
If you have a cruise in your plans, it might be wise to think about how to minimize infection risk. Simple practices like wearing masks, washing hands often, and spending time on deck could help reduce the chances of having to isolate until reaching the next port.
Even with my background in epidemiology, I’m considering a cruise with my family next year. It’s not a choice I’d make lightly, but when weighing the pros and cons, it doesn’t seem like the worst idea in the world.
