Traveller's diarrhoea

Many people who travel from developed to developing countries experience traveller’s diarrhoea. This illness can occur at any time during the trip, or even after the person gets home. It is usually a self-limiting condition that clears up after a few days. It is often caused by eating contaminated food or water. The micro-organisms that trigger the illness may appear to be harmless to the local population, presumably because local people have acquired immunity to them.

The risk of traveller’s diarrhoea is higher where sanitation and hygiene standards are poor, such as in the developing nations of Latin America, Africa, the Middle East and Asia. Traveller’s diarrhoea is more common in young adults than older adults, probably because younger people tend to choose more adventurous destinations or styles of travel, like backpacking.

Other names for traveller’s diarrhoea include Montezuma's revenge, Bali belly and the Rangoon runs.

Symptoms of traveller’s diarrhoea

The symptoms include:

• abdominal bloating, cramps and pain
• nausea
• urgency to go to the toilet
• loose, watery stools (faeces or poo) passed frequently
• mild temperature
• general malaise (weakness or discomfort).

Causes of traveller’s diarrhoea

Micro-organisms that can cause traveller’s diarrhoea include:

• Bacteria – Escherichia coli (E. coli), primarily enterotoxigenic strains (ETEC). This is one of the most common bacterial causes of traveller’s diarrhoea. Other bacterial causes of traveller’s diarrhoea include Campylobacter jejuni, Salmonella species and Shigella species. These infections are usually associated with severe abdominal pains and fever
• Parasites – certain parasitic infections are known to cause diarrhoea, including Giardia intestinalis, Entamoeba histolytica and Cryptosporidium parvum. In these cases, the illness lasts longer than a few days and the stools may be bloody
• Viruses – some estimates suggest that around one in three cases of traveller’s diarrhoea is caused by or associated with a viral infection, particularly norovirus and rotavirus
• Unknown causes – a cause can't be found in approximately one-fifth to half of all cases of traveller’s diarrhoea. It is thought that diarrhoea may be the gastrointestinal system's response to unfamiliar micro-organisms.

Traveller’s diarrhoea contamination risk foods

Consuming contaminated food is a major cause of traveller’s diarrhoea. Some high-risk foods that the wary traveller should avoid include:

• raw and peeled fruits and vegetables
• green leafy vegetables such as spinach and lettuce
• raw, rare or undercooked meats of any kind
• seafood, particularly raw or inadequately cooked shellfish or fish
• sauces and mayonnaises
• unpasteurised dairy foods, including milk
• food from street vendors
• any hot food that has been left long enough to cool
• food buffets.

Contaminated water and traveller’s diarrhoea

Water contaminated with infected faeces is another common cause of traveller’s diarrhoea. Tips include:

• If you are not sure of the safety of the water supply, avoid drinking the water or brushing your teeth with it.
• Buy bottled water to drink, preferably carbonated.
• Boil tap water for at least five minutes before drinking it.
• Avoid any drinks that contain ice.
• Avoid using tap water to wash your fruit and vegetables.

Hygiene practices to prevent traveller’s diarrhoea

You can further reduce your risk of traveller’s diarrhoea by practicing good hygiene. Tips include:

• Wash your hands with soap and water after going to the toilet, and before eating or preparing food.
• After washing your hands, make sure they are completely dry before you touch any food.
• Make sure any dishes, cups or other utensils are completely dry after they are washed.
• Eat at reputable and clean restaurants.

Preventing traveller’s diarrhoea in children

Children with traveller’s diarrhoea are more vulnerable to dehydration and need plenty of suitable drinks. To help prevent infection in children:

• Don't allow small children to crawl around on floors.
• Make sure your child doesn't put their unwashed fingers into their mouth.
• Wash their hands frequently.
• When making up formula milk, either use bottled water or thoroughly boil tap water for at least five minutes.

Vaccination against traveller’s diarrhoea

As well as the precautions above, the use of the oral cholera vaccine has been shown to reduce the overall incidence of traveller’s diarrhoea by half, and is now often recommended by travel physicians. This secondary benefit is due to its suppression of the bacteria E. coli. It can be used in adults and children over the age of two.

Diagnosis of traveller’s diarrhoea

Traveller’s diarrhoea is usually diagnosed by considering the person's medical history and a physical examination. However, a stool sample may be required for testing if diarrhoea persists. Different infectious agents respond to different medication, so it is important to find out which germ is causing the illness.

Treatment for traveller’s diarrhoea

Currently there are no vaccines that can reliably prevent traveller’s diarrhoea. The best defence is prevention. In most cases, traveller’s diarrhoea is self-limiting and tends to clear up in around four days.

Treatment aims to ease some of the symptoms and prevent dehydration. Options may include:

• plenty of water to avoid dehydration
• oral rehydration drinks to replace lost salts and minerals
• antibiotics to kill a bacterial infection
• anti-nausea drugs
• dairy foods can worsen diarrhoea in some people, so limit consumption of these foods
• avoiding alcohol and spicy foods
• avoiding anti-diarrhoea drugs if you have a high fever – preventing the passage of stools will only keep a bacterial infection and its poisons inside the body for longer.

Repeat attacks of traveller’s diarrhoea

Enduring one bout of traveller’s diarrhoea doesn't offer any protection against developing it again. This is because so many different infectious agents are capable of causing the illness.

Where to get help

• Your doctor
• Pharmacist

Things to remember

• Many people experience traveller’s diarrhoea.
• Symptoms of traveller’s diarrhoea include abdominal pain, cramps and the need to urgently and frequently pass watery stools (faeces).
• Generally, the cause is consumption of contaminated food or water. In some cases, the micro-organisms that trigger the illness are quite harmless.
• It is usually a self-limiting condition that clears up after a few days.