I've taken almost 30 cruises, and over that time, developed a standard list of things I check before booking: itinerary, cabin location, price, dates, and the ship's age (newer ships tend to be nicer with more amenities).
What I only recently started checking, however, was the sanitation inspection score issued by the Centers for Disease Control and Prevention (CDC). Although I wouldn’t consider myself a “germaphobe,” thousands of people roll through cruise ships with minimal turnaround between sailings. The question of, “How clean and healthy are these ships, really?” started to enter my mind.
I learned that all cruise ships have a health record, and that the CDC’s Vessel Sanitation Program (VSP) maintains a list of gastrointestinal illness outbreaks with details on when the last one occurred, and how many people were reported sick. Separately, VSP inspectors regularly evaluate ships against public-health standards in areas such as food service, drinking water, and housekeeping.
While some of these details can feel a little yucky, remember, a sanitation score is not the same thing as a cleanliness rating or as a measure of outbreak risk. Rather, it records compliance with public health standards on one inspection day. Here’s what you need to know before boarding your next cruise.
In this article
What Gets a Ship on the CDC Outbreak List?
It is easy to check if your cruise ship has been on the CDC outbreak list. The CDC's Vessel Sanitation Program tracks gastrointestinal illness on cruise ships under its jurisdiction. A ship reaches the CDC's outbreak threshold when 3 percent or more of its passengers or crew report gastrointestinal illness during a voyage.
The CDC's definition includes three or more loose stools in 24 hours, or vomiting accompanied by diarrhea, muscle aches, headache, abdominal cramps, or fever.
At 2 percent, the CDC begins providing support and technical assistance; at 3 percent, it considers the illness level an outbreak.
Percentages Don’t Tell the Whole Story
Seeing your ship listed as having an outbreak can be jarring, but just remember, ship size matters a lot here. All it takes is a handful of sick passengers on a small expedition vessel to hit that threshold, while that same percentage would require hundreds of passengers on a mega ship.
For example, on a small expedition ship carrying 62 passengers, just two sick passengers would be enough to reach 3 percent. On a larger ship carrying 4,000 passengers, it would take 120.
So when you see “3 percent” in a CDC outbreak report, check the actual number of people who reported being sick to get a complete picture of what really happened.
Why Some Outbreaks Are Due to "Unknown Causes"
According to the CDC, norovirus and E. Coli were sometimes listed as known outbreak causes for cruise ships in 2026. In other cases, a cruise ship outbreak is reported as due to “unknown causes," which means exactly what it sounds like. The CDC does not have enough information to determine the cause of the outbreak.
It does not mean, however, that the illness itself was unusual or mysterious. Just that they can’t rule a cause for certain.
The CDC may investigate an outbreak and collect samples for testing, but those samples don't always provide enough information to properly pinpoint the cause. In the case of National Geographic Sea Bird's July 2026 outbreak, the CDC collected samples, but they were insufficient for testing.
Don't Confuse an Outbreak With a Sanitation Score
The CDC's outbreak list and sanitation inspection database measure different things. An outbreak tells you that people got sick during a particular voyage. A sanitation inspection looks at the ship's public-health practices when inspectors visit.
It's natural to look at the two and assume a low inspection score means a ship is more likely to have an outbreak, but that's not what the score tells you. It measures how well the ship complied with health rules on the day of the inspection, not whether passengers will get sick.
Whether or not people have gotten sick, I find looking at the sanitation inspection data to be helpful when deciding what cruise to take. It doesn’t help with basics, like choosing a cruise ship cabin, but it does give me helpful, top-down information about the ship as a whole.
How to Use This Information
With this data available, I now check both CDC databases before booking a cruise, but for different reasons.
The outbreak list tells me whether a ship has recently had a gastrointestinal illness outbreak, how many people were sick, and whether the CDC identified a cause.
The sanitation inspection database, meanwhile, gives me a broader view of how the ship handles public-health practices over time. I also read the actual inspection report, not just the score, to see what inspectors found.
The reports are easy to find and understand, so I don't have to dig through a bunch of technical information to get the basics. And I also keep in mind that getting sick while traveling can happen anyway (and come with unexpected costs) for other reasons, too.
But for me, all of this information is useful, and provides added peace of mind before I commit to a cruise.
The Shortcut
Check the CDC's outbreak list for recent gastrointestinal illness outbreaks, including the dates, number of sick passengers or crew, and whether a cause was identified.
You can also look at the ship's CDC sanitation inspection report, not just its score, and look for the violations inspectors may have found.
Pay attention to the number of people who got sick, not just the percentage. A 3 percent outbreak can mean very different numbers on different-sized ships. Use the information as one part of your booking decision, not as a prediction of whether you'll get sick.
