What is traveller's diarrhoea?

Traveller's diarrhoea is an acute (short-term) infection of your stomach and intestines. It mainly affects residents of developed countries travelling to sub-tropical or third-world regions, with an estimated 40 million cases worldwide each year. [1]  While the condition itself is not usually serious, it can cause severe dehydration in vulnerable individuals. Some of the highest-risk areas are Asia, South and Central America, Africa and the Middle East. It can be caused by poor hygiene and food-handling procedures, and water contamination.

A wide range of bacteria, viruses and parasites can cause traveller's diarrhoea. The usual symptoms are diarrhoea, often with nausea and fatigue. Traveller's diarrhoea usually passes within 3-4 days without incident if you are healthy. However, if you are very young or old, or have depleted immunity, it can be more serious and even fatal if left untreated.

Dehydration

The state of insufficient hydration; excessive loss of water; requiring more water in order to function normally.

1. De la Cabada Bauche J. and DuPont H.L. (2011) New developments in traveler’s diarrhea. Gastroenterology and Hepatology 7:88-95.

Causes

The main cause of traveller's diarrhoea is infection from bacteria, viruses or parasites. They are commonly due to consuming contaminated food or water. They usually cause the lining of the intestines to become inflamed and irritated. This inflammation stops water from being absorbed, which causes watery stools.

Bacteria

Bacteria are responsible for up to 80% of traveller's diarrhoea cases. [2]  Common bacterial infections known to cause traveller's diarrhoea are:

  • Escherichia coli (E. coli) - this strain of bacteria is responsible for most cases of traveller's diarrhoea in developing nations. It is transmitted by consumption of water and food contaminated with human waste (faeces). It typically affects those who have not built up an immunity to it, which means you may dine with locals and be the only person to fall ill, and;
  • Salmonella, Shigella, Staphylococcus aureus, Vibrio cholera and Campylobacter bacteria are also common bacteria that lead to diarrhoea. Infection can be spread due to poor hygiene, eating contaminated foods, undercooked meat (especially chicken), or contact with animal or human waste. 

Street vendor food may be contaminated by bacteria. 

Viruses

Viral infections can also cause traveller's diarrhoea. They are highly contagious, therefore they easily spread to your fellow travellers. These viruses include:

  • Norovirus - symptoms can be severe;
  • Rotavirus;
  • Adenovirus - symptoms of this can also include a sore throat, conjunctivitis and respiratory infection, but these are rarely serious, and;
  • Astrovirus.

Parasites

Intestinal parasites such as Giardia lamblia, Entamoeba histolytica and Cryptosporidium can cause an infection of the digestive system with nausea, watery diarrhoea and severe cramping. Poor handwashing and contact with animal or human wastes are the usual causes of infection.   

Unknown cause

In a large percentage of cases, no cause may be found for your diarrhoea. It may be due to your digestive system being intolerant to local foods, due to a food allergy or having an infection, which is not easily diagnosed.

2. Leder K. (2015) Advising travellers about management of travellers’ diarrhoea. Australian Family Physician 44:34-37.

Risk factors

Travel to developing or tropical regions

If you live in an developed country, it is very common to experience traveller's diarrhoea while travelling through developing nations, where sanitation and food hygiene standards may be poor. Infectious agents may be present in drinking water, food and on communal surfaces such as doorhandles or handrails.

Age

While traveller's diarrhoea can happen to anyone, young children tend to be at increased risk.

Weak immune system

You are at greater risk if you have a weakened immune system, heart disease, or due to medications such as proton pump inhibitors (used for heartburn and stomach ulcers) and anti-inflammatories (such as prednisolone).

Time of year

The time of year you travel can influence your chances of becoming ill. In temperate South-East Asia, the hot months just before the monsoon season provide a greater risk of traveller's diarrhoea.

Ulcers

An open sore in the skin or mucous membranes such as those of the stomach lining, intestine or mouth.

2. Leder K. (2015) Advising travellers about management of travellers’ diarrhoea. Australian Family Physician 44:34-37.

Types

The different types of traveller's diarrhoea are classified according to the symptoms you are experiencing. The main concern for your doctor will be to identify and treat dehydration, as a result of fluid losses in your stools.

Mild

You have had one or two episodes of diarrhoea in the previous 24 hours, but no other symptoms.

Moderate

You have had at least two episodes of diarrhoea in the past 24 hours and one or more of the following symptoms: abdominal pain, nausea, vomiting, fever, or blood in the stools.

Severe

You have had three or more episodes of diarrhoea in the past 24 hours and one or more of the following symptoms: abdominal pain, nausea, vomiting, fever, or blood in the stools. Severe traveller's diarrhoea often leads to dehydration and can require hospitalisation for rehydration.

Dehydration

The state of insufficient hydration; excessive loss of water; requiring more water in order to function normally.

2. Leder K. (2015) Advising travellers about management of travellers’ diarrhoea. Australian Family Physician 44:34-37.

Signs and symptoms

The signs and symptoms of traveller's diarrhoea, which tend to happen very abruptly. They include:

  • Diarrhoea, usually explosive, urgent and watery. About 4-5 (or more) episodes a day can be expected;
  • Severe stomach cramps with bloating;
  • Loss of appetite;
  • Nausea and vomiting;
  • Muscle aches and tiredness, and;
  • Sometimes, fever and headache.

Traveller's diarrhoea can cause severe stomach cramps and bloating. 

2. Leder K. (2015) Advising travellers about management of travellers’ diarrhoea. Australian Family Physician 44:34-37.

Methods for diagnosis

While the majority of cases go undiagnosed, your doctor may suggest the following tests to find the cause of your diarrhoea:

  • Blood tests - to check your blood count, electrolytes and liver function;
  • Stool microscopy, culture and sensitivity (MCS) - this uses a stool sample to check for bacteria, viruses and parasites, and;
  • Stool polymerase chain response - this test uses a stool sample to rapidly detect the presence of viruses and some bacteria. 

Electrolytes

Substances that form ions when dissolved in water. These include potassium and sodium minerals that are necessary for normal functioning of the body and all its cells.

Stool microscopy, culture and sensitivity

A stool test used to check if there is a disease-causing organism or virus in the digestive tract with the added benefit of finding which medications would be most useful in targetting that organism or virus.

2. Leder K. (2015) Advising travellers about management of travellers’ diarrhoea. Australian Family Physician 44:34-37.

Types of treatment

Depending on the severity of your symptoms, you may be advised to stay at home and do the following:

Self care

The following measures may be of help:

  • Have complete bed rest to conserve your energy;
  • Regularly wash your hands with soap, especially after visiting the toilet, to prevent infecting others or re-infecting yourself;
  • Take small sips of clear liquids to stay hydrated, preferably water and oral rehydration drinks;
  • Avoid spicy or greasy foods and try to eat mainly bland foods, such as dry crackers, until your symptoms settle, and;
  • Unless prescribed by your doctor, avoid taking antibiotics, antidiarrhoeal or anti-nausea medications, which can prolong infections and delay recovery.

For severe cases, hospitalisation for dehydration is not uncommon and may involve insertion of an intravenous (IV) drip or nasogastric tube, to get fluids back into your system.  

Medications

In most cases of traveller's diarrhoea, unless severe, medications may not be needed. Unless prescribed by your doctor, medications can make your condition worse. Parasitic and some bacterial infections can be treated with anti-parasitic medications and antibiotics, respectively. Sometimes, anti-nausea and antidiarrhoeal medications may also be prescribed by your doctor.

Dehydration

The state of insufficient hydration; excessive loss of water; requiring more water in order to function normally.

Intravenous

Within a vein.

2. Leder K. (2015) Advising travellers about management of travellers’ diarrhoea. Australian Family Physician 44:34-37.

Potential complications

Dehydration

The state of insufficient hydration; excessive loss of water; requiring more water in order to function normally.

Electrolyte

Substances that form ions when dissolved in water. These include potassium and sodium minerals that are necessary for normal functioning of the body and all its cells.

Haemolytic-uraemic disorder

A rare condition triggered by certain infections, medications or unknown factors, which causes the rapid destruction of red blood cells and subsequently life-threatening kidney failure.

2. Leder K. (2015) Advising travellers about management of travellers’ diarrhoea. Australian Family Physician 44:34-37.

Prognosis

The outlook for most cases of traveller's diarrhoea is good. The main concern though, is dehydration, which can prove dangerous.

Dehydration

The state of insufficient hydration; excessive loss of water; requiring more water in order to function normally.

2. Leder K. (2015) Advising travellers about management of travellers’ diarrhoea. Australian Family Physician 44:34-37.

Prevention

Avoiding risk factors is the main way to reduce your incidence of developing traveller's diarrhoea:

  • Only drink bottled water -  also use it to brush your teeth;
  • Do not have ice in drinks;
  • Avoid unpasteurised milk products;
  • Only drink bottled or canned beverages and clean the lid with a cloth beforehand;
  • Avoid all raw or peeled fruits and vegetables (or peel them yourself);
  • Avoid green leafy vegetables, such as spinach and lettuce, that may have been washed in tap water;
  • Avoid raw or undercooked meat, especially poultry;
  • Avoid food from street vendors;
  • Do not eat food that has been left sitting outside for too long, and;
  • Avoid food buffets.

Discuss vaccination requirements and travel hygiene with your doctor prior to travelling. Some doctors may also provide a useful traveller's medical kit that can include simple medications and written advice for diarrhoea.

Good hygiene

  • Always wash your hands with soap and water, and dry them thoroughly, after using the toilet and before preparing foods;
  • Wash and thoroughly dry any cooking utensils or glasses after use;
  • Use an alcohol-based hand sanitiser when unable to wash hands, and;
  • Ensure raw and cooked foods are not handled using the same utensils, and do not allow them to come into contact with each other.

Prevention for children

  • Do not allow children to put unwashed hands in their mouths;
  • Do not allow them to play on the floor in risky areas - put down a blanket or rug;
  • Only offer bottled or boiled water;
  • Discuss travel vaccination requirements for your children at least two weeks prior to travelling;
  • Do not allow children to play in water that may be contaminated, and;
  • Ensure children wash their hands often, especially before eating and after visiting the bathroom.

Avoid contaminated water

Infectious agents are often present in water that may look clean. In areas with poor sanitation, water is often contaminated by animal and human waste and chemical run-off.

If you are considering swimming in a pool, spa, lagoon or river, it is advisable to keep the following in mind:

  • Do not enter if you have open cuts, wounds, fresh piercings or tattoos;
  • Keep your head above water and do not let it enter eyes, ears or your mouth, and;
  • Keep small children and babies out of the water.

Vaccination

It is difficult to avoid developing traveller's diarrhoea, but some vaccines may help prevent diarrhoeal disease. Typhoid fever and cholera are two diarrhoeal illnesses that have vaccinations. Discuss your vaccination requirements with a travel doctor at least two weeks prior to travel.

2. Leder K. (2015) Advising travellers about management of travellers’ diarrhoea. Australian Family Physician 44:34-37.