I’m a former USDA food expert – here’s how to avoid stomach bugs when eating on vacation and on cruises.

A stomach bug is the last thing anyone wants on vacation: to be forced to spend their days off curled up next to the bathroom.

But a food safety expert told DailyMail.com that could be the reality for hundreds of people traveling on cruise ships.

Dr Darin Detwiler, a leading US food safety expert, told DailyMail.com that viruses such as E.coli, salmonella and norovirus are common on cruise ships due to overcrowding, the thousands of people on board and the large volume of community food.

Highly contagious infections are transmitted through contaminated food, water, or improper food handling, and cause abdominal cramps, vomiting, diarrhea, fever, chills, and fatigue.

In severe cases, patients may become dehydrated or suffer organ failure and need to be hospitalized.

CDC’s Vessel Sanitation Program (VSP) tracks and inspects gastrointestinal illness outbreaks on cruise ships and in 2024, the agency recorded 10 incidents affecting 1,040 passengers.

Of those outbreaks, seven were caused by norovirus, while three were caused by salmonella or E. coli.

These viruses are usually caused by ingesting water or food contaminated with feces, or by eating undercooked foods, such as meat, eggs, or fish. Viruses can then spread when someone comes into contact with an infected person or a surface that a sick person has touched.

Overall, the CDC estimates that between two and four percent of cruise passengers experience these illnesses each year.

And with approximately 31.7 million people sailing worldwide, more than 500,000 could get sick.

Cruise ships face “unique challenges” when it comes to food safety, Dr. Detwiler notes, “particularly because they serve large numbers of passengers in confined spaces where diseases can spread quickly.” They are like floating cities.’

He added: ‘Cruise ships also often source food internationally, calling at various ports to replenish supplies. “This can lead to different safety standards, especially when it comes to fresh produce, meats and seafood.”

While most gastrointestinal illnesses involve mild symptoms, vulnerable populations, such as young children, the elderly, and pregnant women, may face more serious complications such as severe dehydration, organ failure, or, in extreme cases, death.

To reduce the chances of getting sick at sea, the university professor told this website his seven safety measures.

WASH YOUR HANDS FREQUENTLY, THE OLD WAY

The most effective way to prevent infections on cruise ships, Dr. Detwiler said, is to wash your hands regularly with soap and water for 20 seconds, or the duration of two happy birthday songs.

He noted that this is a particularly important thing to do before meals.

While alcohol-based hand sanitizers are “helpful,” they may be “less effective against norovirus, so prioritize handwashing.”

In an attempt to get young children into the habit of washing their hands, Dr. Detwiler recommended educating them about stomach viruses and the possibility of getting sick.

AVOID THE BUFFET AT PEAK TIMES

Dr. Detwiler advises dining during off-peak hours, when the buffet’s food rotation is highest, or opting for made-to-order dishes.

Buffets are known to be contamination hotspots, especially when food is left out for long periods.

To minimize risk, Dr. Detwiler advises dining during off-peak hours, “when food turnover is highest, or opting for made-to-order items.”

During peak hours, there is more risk of contamination as people crowd around food stalls.

The CDC emphasizes that hot foods should be “steaming,” while cold foods should be visibly cold.

The agency said: “The germs that cause food poisoning grow rapidly when food is in the danger zone, between 40 degrees Fahrenheit and 140 degrees Fahrenheit.”

These temperatures allow bacteria to multiply more quickly, and norovirus and E. coli germs will flourish.

Norovirus is the most common type of stomach virus and usually occurs when a sick person touches food before serving it. However, foods such as fish and shellfish can be naturally contaminated with it.

While most people recover without complications, severe vomiting and diarrhea can cause dehydration and require medical attention.

E.coli is a bacteria that causes similar symptoms. It can also be found in raw and undercooked meats. Most strains are mild, but some can cause severe cramps and bloody diarrhea.

WATCH HOW FOOD IS PREPARED

While visiting buffet stations on the ship or other dining areas, Dr. Detwiler told DailyMail.com that it is important to observe how food and drinks are prepared.

Some of his pet peeves include waiters not wearing gloves, dirty serving spoons, and food stored at incorrect temperatures.

Meanwhile, at cruise ship bars, he said drink garnishes should be avoided.

A 2007 study published in the Journal of Environmental Health found that nearly 70 percent of lemon slices used as a bar garnish were contaminated with bacteria.

Dr. Detwiler says if you notice unhealthy activities while surfing, “it’s very important to speak up and say something.”

SKIP THE OYSTERS AND STEAK TARTAR

“Raw seafood and undercooked meats, such as Steak Tartare or rare steaks, are more likely to carry pathogens,” Dr. Detwiler said.

While raw bars, packed with everything from oysters to clams, are considered an extravagant seafood dining option, Dr. Detwiler advises staying away from them.

In fact, it recommends avoiding raw or undercooked foods altogether due to possible contamination.

He explained: ‘Raw seafood and undercooked meats, such as steak tartare or rare-cooked ribeyes, are more likely to carry pathogens. You’re even at risk with runny eggs.

“Opt for well-cooked dishes to reduce the risk of exposure to salmonella or listeria.”

People with salmonella develop stomach problems and fever, which can become serious and require hospitalization.

Many of these foods can also harbor Listeria, which is It is usually found in unpasteurized milk, soft cheeses, ready-to-eat foods, fish, sausages and pre-cut fruits.

Most people with listeria will not become seriously ill. But in some cases it can cause confusion and seizures, miscarriages in pregnant women, and even death.

STICK TO BOTTLED WATER AND BE CAREFUL WITH ICE

Although cruise ships purify their water, Dr. Detwiler said bottled water is a “much safer option and worth paying a little extra for.”

This is because the water on cruise ships could be contaminated with enterotoxigenic Escherichia coli (ETEC), a type of E. coli bacteria that can cause diarrhea. It may also be the source of legionella, a bacteria that can cause Legionnaires’ disease.

Legionnaires’ pneumonia is a serious type of pneumonia that can cause difficulty breathing as well as gastrointestinal symptoms. About 10 percent of people who contract the disease die.

For this reason, if you can, you should also consider doing without ice in your drinks, Dr. Detwiler told DailyMail.com.

He added: “Be careful when drinking tap water or using ice, especially when docked in foreign ports where water quality can vary.”

CUT AND PEEL YOUR OWN FRUIT

Instead of cut fruit, Dr. Detwiler recommends selecting whole fruits from cafeterias and “cut or peel them yourself to avoid contamination.”

While melon slices and pineapple chunks may look appealing on buffet counters, Dr. Detwiler reveals that “pre-cut fruits carry the risk of being exposed to bacteria.”

In recent years there have been several outbreaks of fruit-related bacteria. More recently, in 2023, there was a national salmonella outbreak linked to melons, with 407 people sick and six deaths.

For this reason, Dr. Detwiler says he will “always avoid cantaloupe because of how often it becomes contaminated and causes illness and death.”

Instead of cutting fruit, he recommends selecting whole fruits from canteens and “cut or peel them yourself to avoid contamination.”

SKIP STREET FOOD ON LAND

The risk of stomach illnesses on cruise ships extends beyond the ship.

Most cruise companies offer shore excursions, where vacationers leave the ship and explore an area during the day, giving people the opportunity to try local cuisine.

But Dr. Detwiler warned against street food, especially when high temperatures can serve as a breeding ground for harmful bacteria.

It says: ‘When exploring at port stops, be aware of food safety regulations at local markets.

“Stick to reputable restaurants and avoid street food that may not meet the same hygiene levels as the cruise ship.”