What is traveller's diarrhoea?

traveller's diarrhoea is diarrhoea that develops during, or shortly after, you have travelled abroad. Diarrhoea is defined as 'loose or watery stools (faeces), usually at least three times in 24 hours'.

What causes traveller's diarrhoea?

traveller's diarrhoea is caused by eating food, or drinking water, contaminated by microbes (germs). Bacteria are the most common microbes that cause traveller's diarrhoea. Escherichia coli, Campylobacter, Salmonella and Shigella are commonly implicated. Viruses are the next most common, particularly norovirus and rotavirus. Parasites are less common causes. Giardia, Cryptosporidium and Entamoeba histolytica are examples of parasites that may cause traveller's diarrhoea.

Often the exact cause of traveller's diarrhoea is not found and studies have shown that in up to half of people, no specific microbe is identified despite testing (for example of a stool specimen).

Note: there are separate leaflets that give more specific details on each of the microbes mentioned above. This leaflet is about traveller's diarrhoea in general and how to help prevent it.

Are all travellers at risk?

traveller's diarrhoea most commonly affects people who are travelling from a developed country, such as the UK, to a less developed country where sanitation and hygiene measures may not meet the same standards.

Those travelling to the Middle East, Africa, Central and South America and many parts of Asia are most at risk of developing traveller's diarrhoea. Between 3 and 5 in every 10 people travelling to such areas from the UK develop symptoms of traveller's diarrhoea during a 1- to 2-week stay. People who travel within western Europe, to the United States of America, and to countries such as Australia and New Zealand have a 'low' risk of developing traveller's diarrhoea. Those visiting eastern European countries, Russia, South Africa, and some of the Caribbean islands have an 'intermediate' risk.

Sometimes outbreaks of diarrhoea can occur in travellers staying in one hotel or, for example, those staying on a cruise ship. People travelling in more remote areas, for example trekkers and campers, may also have limited access to medical care if they do become unwell.

What are the symptoms of traveller's diarrhoea?

By definition, diarrhoea is the main symptom. This can be watery and can sometimes contain blood. Other symptoms may include crampy abdominal pains, nausea, vomiting and fever.

Symptoms are usually mild in most people and last for 3 to 4 days but they may last longer. Symptoms may be more severe in the very young, the elderly, and those with other health problems, particularly those with compromised immune systems, such as people with HIV infection, on long-term steroid treatment, etc.

Despite the fact that symptoms are usually fairly mild, they can often mean that your travel itinerary or business trip is interrupted or may need to be altered.

Do I need any investigations?

traveller's diarrhoea is usually diagnosed by the typical symptoms. As mentioned above, most people have mild symptoms and do not need to seek medical advice. However, in some cases medical advice is needed (see below).

If you do see a doctor, they may suggest that a sample of your stool be tested. This will be sent to the laboratory to look for any microbes that may be causing your symptoms. Sometimes blood tests or other tests may be needed if you have more severe symptoms or develop any complications.

When should I seek medical advice?

As mentioned above, most people with traveller's diarrhoea have relatively mild symptoms and can manage these themselves by resting and making sure that they drink plenty of fluids. However, you should seek medical advice in any of the following cases, or if any other symptoms occur that you are concerned about:

• If you have a fever.
• If you have blood in your stools.
• If there are signs of dehydration:
  • Symptoms of dehydration in adults include: tiredness, dizziness or light-headedness, headache, muscular cramps, sunken eyes, passing little urine, a dry mouth and tongue, weakness, and becoming irritable. Symptoms of severe dehydration in adults include: weakness, confusion, rapid heart rate, coma, and a greatly reduced amount of urine that you make. This is a medical emergency.
  • Symptoms of dehydration in children include: passing little urine, a dry mouth, a dry tongue and lips, fewer tears when crying, sunken eyes, weakness, being irritable or lethargic. Symptoms of severe dehydration in children include: drowsiness, pale or mottled skin, cold hands or feet, very few wet nappies, fast (but often shallow) breathing. This is a medical emergency and immediate medical attention is needed.
• If it is difficult to maintain hydration because of severe symptoms: frequent or very watery stools or repeated vomiting.
• If the diarrhoea lasts for more than 3 or 4 days.
• If you have started antibiotics yourself and the diarrhoea does not start to improve within 3 days of treatment.
• If you are elderly or have an underlying health problem such as diabetes, inflammatory bowel disease, kidney disease.
• If you have a weakened immune system because of, for example, chemotherapy treatment, long-term steroid treatment, HIV infection.
• If you are pregnant.
• If an affected child is under the age of six months.

What is the treatment of traveller's diarrhoea in adults?

In most cases, traveller's diarrhoea does not need any specific treatment. The most important thing is to make sure that you drink plenty of fluids to avoid dehydration.

Fluid replacement

• As a rough guide, drink at least 200 mls after each bout of diarrhoea (after each watery stool).
• This extra fluid is in addition to what you would normally drink. For example, an adult will normally drink about two litres a day, but more in hot countries. The above '200 mls after each bout of diarrhoea' is in addition to this usual amount that you would drink.
• If you vomit, wait 5-10 minutes and then start drinking again, but more slowly. For example, a sip every 2-3 minutes, but making sure that your total intake is as described above.
• You will need to drink even more if you are dehydrated. A doctor will advise on how much to drink if you are dehydrated. Note: if you suspect that you are becoming dehydrated, you should seek medical advice.

For most adults, fluids drunk to keep hydrated should mainly be water. However, this needs to be safe drinking water - for example, bottled, or boiled and treated water. It is best not to have drinks that contain a lot of sugar such as cola or pop as they can sometimes make diarrhoea worse. Alcohol should also be avoided.

Rehydration drinks may also be used. They are made from sachets that you can buy from pharmacies and may be a sensible thing to pack in your first aid kit when you travel. You add the contents of the sachet to water. Rehydration drinks provide a good balance of water, salts, and sugar. They do not stop or reduce diarrhoea. However, the small amount of sugar and salt helps the water to be absorbed better from the gut into the body. Do not use home-made salt/sugar drinks, as the quantity of salt and sugar has to be exact. Note that safe drinking water should be used to reconstitute oral rehydration salt sachets.

Antidiarrhoeal medication

Antidiarrhoeal drugs are not usually necessary. However, you may wish to reduce the number of trips that you need to make to the toilet. You can buy antidiarrhoeal drugs from pharmacies before you travel. The safest and most effective is loperamide. The adult dose of this is two capsules at first. This is followed by one capsule after each time you pass some diarrhoea up to a maximum of eight capsules in 24 hours. It works by slowing down your gut's activity.

An alternative is Pepto-Bismol®. However, some people should not take Pepto-Bismol®. They include people who are allergic to aspirin, people on anticoagulant treatment such as warfarin, people with kidney problems, or people with gout. Read the leaflet carefully or ask your doctor or pharmacist before you travel if it is safe for you to take Pepto-Bismol®.

You should not take loperamide or Pepto-Bismol® for longer than two days. You should also not use antidiarrhoeal drugs if you have a fever or bloody diarrhoea.

Eat as normally as possible

It used to be advised to 'starve' for a while if you had diarrhoea. However, now it is advised to eat small, light meals if you can. Be guided by your appetite. You may not feel like food and most adults can do without food for a few days. Eat as soon as you are able but don't stop drinking. If you do feel like eating, avoid fatty, spicy or heavy food. Plain foods such as bread and rice are good foods to try eating.

Antibiotics

Most people with traveller's diarrhoea do not need treatment with antibiotics. However, sometimes antibiotic treatment is advised. This may be because a specific microbe has been identified after testing of your stool sample.

Also, in general, it is not necessary to take antibiotics on holiday with you 'just in case' you get traveller's diarrhoea. This is because, as mentioned above, most people do not need medical attention and do not need antibiotic treatment. Your immune system clears the infection after a few days without any specific treatment. Also, it may be a viral infection that is causing your symptoms which won't be treated by antibiotics. Antibiotic treatment may also have side-effects and microbes may start to develop resistance to certain antibiotics if they are used unnecessarily.

Saying that, for certain groups of people, it may be advised to take some 'just in case' antibiotics with you when you travel so that you can start to take them if you develop symptoms. The World Health Organization recommends that 'just in case' antibiotics should be considered for those staying in places where medical assistance is poor or not available. It should be started if bowel movements become 'very frequent, very watery or contain blood, or last beyond 3 days'. Ciprofloxacin or azithromycin are usually the antibiotics that are used.

What is the treatment of traveller's diarrhoea in children?

Fluids to prevent dehydration

You should encourage your child to drink plenty of fluids. The aim is to prevent dehydration. The fluid lost in their vomit and/or diarrhoea needs to be replaced. Your child should continue with their normal diet and usual drinks. In addition, they should also be encouraged to drink extra fluids. However, avoid fruit juices or fizzy drinks as these can make diarrhoea worse.

Babies under six months old are at increased risk of dehydration. You should seek medical advice if they develop acute diarrhoea. Breast- or bottle-feeds should be encouraged as normal. You may find that your baby's demand for feeds increases. You may also be advised to give extra fluids (either water or rehydration drinks) in between feeds.

It is sensible to consider buying oral rehydration sachets for children before you travel. These can provide a perfect balance of water, salts, and sugar for them and can be used for fluid replacement. Remember that, as mentioned above, safe water is needed to reconstitute the sachets.

If your child vomits, wait 5-10 minutes and then start giving drinks again, but more slowly (for example, a spoonful every 2-3 minutes). Use of a syringe can help in younger children who may not be able to take sips.

Note: if you suspect that your child is dehydrated, or is becoming dehydrated, you should seek medical advice urgently.

Fluids to treat dehydration

If your child is mildly dehydrated, this may be treated by giving them rehydration drinks. A doctor will advise about how much to give. This can depend on the age and the weight of your child. If you are breast-feeding, you should continue with this during this time. Otherwise, don't give your child any other drinks unless the doctor has said that this is OK. It is important that your child be rehydrated before they have any solid food.

Sometimes a child may need to be admitted to hospital for treatment if they are dehydrated. Treatment in hospital usually involves giving rehydration solution via a special tube called a 'nasogastric tube'. This tube passes through your child's nose, down their throat and directly into their stomach. An alternative treatment is with intravenous fluids (fluids given directly into a vein).

Eat as normally as possible once any dehydration has been treated

Correcting any dehydration is the first priority. However, if your child is not dehydrated (most cases), or once any dehydration has been corrected, then encourage your child to have their normal diet. Do not 'starve' a child with infectious diarrhoea. This used to be advised but is now known to be wrong. So:

• Breast-fed babies should continue to be breast-fed if they will take it. This will usually be in addition to extra rehydration drinks (described above).
• Bottle-fed babies should be fed with their normal full-strength feeds if they will take it. Again, this will usually be in addition to extra rehydration drinks (described above).
• Older children - offer them some food every now and then. However, if he or she does not want to eat, that is fine. Drinks are the most important, and food can wait until the appetite returns.

Medication

Neither loperamide nor Pepto-Bismol® is recommended for children with diarrhoea. There are concerns that loperamide may cause intestinal obstruction in children with diarrhoea. Pepto-Bismol® contains salicylate which should not be used in children under the age of 16 because of the possible association between salicylates and Reye's syndrome (a rare problem causing inflammation of the brain and liver failure).

Most children with traveller's diarrhoea do not need treatment with antibiotics. However, for the same reasons as discussed for adults above, antibiotic treatment may sometimes be advised in certain cases.

Are there any complications?

Most people have mild illness and complications of traveller's diarrhoea are rare. However, if complications do occur, they can include the following:

• Dehydration and salt (electrolyte) imbalance in your body. This is the most common complication. It occurs if the water and salts that are lost in your stools, or when you vomit, are not replaced by your drinking adequate fluids. If you can manage to drink plenty of fluids then dehydration is unlikely to occur, or is only likely to be mild, and will soon recover as you drink. Severe dehydration can lead to a drop in your blood pressure. This can cause reduced blood flow to your vital organs. If dehydration is not treated, kidney failure may also develop. Some people who become severely dehydrated need a 'drip' of fluid directly into a vein. This requires admission to hospital.
• Reactive complications. Rarely, other parts of your body can 'react' to an infection that occurs in your gut. This can cause symptoms such as arthritis (joint inflammation), skin inflammation and eye inflammation (either conjunctivitis or uveitis). Reactive complications are uncommon if you have a virus causing traveller's diarrhoea.
• Spread of infection to other parts of your body such as your bones, joints, or the meninges that surround your brain and spinal cord. This is rare. If it does occur, it is more likely if diarrhoea is caused by Salmonella infection.
• Persistent diarrhoeal syndromes may rarely develop.
• Irritable bowel syndrome is sometimes triggered by a bout of traveller's diarrhoea.
• Lactose intolerance can sometimes occur for a period of time after traveller's diarrhoea. It is known as 'secondary' or 'acquired' lactose intolerance. Your intestine (gut) lining can be damaged by the episode of diarrhoea. This leads to lack of an enzyme called lactase that is needed to help your body digest the milk sugar lactose. Lactose intolerance leads to bloating, abdominal pain, wind and watery stools after drinking milk. The condition gets better when the infection is over and the intestinal lining heals. It is more common in children.
• Haemolytic uraemic syndrome is another potential complication. It is rare and is usually associated with traveller's diarrhoea caused by a certain type of E.coli infection. It is a serious condition where there is anaemia, a low platelet count in the blood, and kidney failure. It is more common in children. If recognised and treated, most people recover well.
• Reduced effectiveness of some drugs. During an episode of traveller's diarrhoea, certain drugs that you may be taking for other conditions or reasons may not be as effective. This is because the diarrhoea and/or vomiting means that reduced amounts of the drugs are absorbed (taken up) into your body. Examples of such drugs are drugs for epilepsy, diabetes and contraception. Speak to your doctor or practice nurse before you travel if you are unsure of what to do if you are taking other drugs and develop diarrhoea.

What is the prognosis (outlook)?

As mentioned above, symptoms are usually short-lived and the illness is usually mild with most people making a full recovery within in few days. However, about 2 in 100 people with traveller's diarrhoea develop chronic diarrhoea that can last for one month or more. It is also possible to get a second 'bout' of traveller's diarrhoea during the same trip. Having it once does not seem to protect you against future infection.

Can traveller's diarrhoea be prevented?

There are a number of things that you can do to help reduce the chance of you getting traveller's diarrhoea.

Regular handwashing

You should ensure that you always wash your hands and dry them thoroughly, and teach children to wash and dry theirs:

• After going to the toilet (and after changing nappies or helping an older child to go to the toilet).
• Before preparing or touching food or drinks.
• Before eating.

If you smoke, you should also wash your hands before smoking. Some antibacterial hand gel may be a good thing to take with you when you travel in case soap and hot water is not available.

Be careful about what you eat and drink

When travelling to areas with poor sanitation, you should avoid food or drinking water that may be contaminated by microbes. Avoid:

• Tap water
• Fruit juices sold by street vendors
• Ice cream (unless it has been made from safe water)
• Ice cubes
• Shellfish (eg mussels, oysters, clams) and uncooked seafood
• Eggs
• Salads
• Raw or undercooked meat
• Fruit that has already been peeled or has a damaged skin
• Food that contains raw or uncooked eggs such as mayonnaise or sauces
• Unpasteurised milk

Bottled water and fizzy drinks that are in sealed bottles or cans, tea, coffee and alcohol are thought to be safe to drink. However, avoid ice cubes in alcoholic drinks. Food should be cooked through thoroughly and be piping hot when served. You should also be careful when eating food from markets or street vendors if you are uncertain about whether it has been kept hot or kept refrigerated. Fresh bread is usually safe as is canned food or food in sealed packs.

Be careful where you swim

Swimming in contaminated water can also lead to traveller's diarrhoea.

Visit your doctor or practice nurse before you travel

Before embarking on any travel abroad, you should visit your doctor or practice nurse in plenty of time to discuss your trip itinerary and get travel advice. There are no vaccines that prevent traveller's diarrhoea as a whole. However, there are some other vaccines that you may need for your travel, such as hepatitis A, typhoid, etc. You may also need to take malaria tablets depending on where you are travelling.

The National Travel Health Network and Centre (NaTHNaC) website www.nathnac.org also provides travel health information for the public and gives specific information for different countries. This includes information about any vaccinations required, advice about food, water, and personal hygiene precautions, etc.

Taking antibiotics to prevent traveller's diarrhoea (antibiotic prophylaxis) is not generally recommended. This is because for most people, traveller's diarrhoea is mild and self-limiting. Also, antibiotics do not protect against nonbacterial causes of traveller's diarrhoea, such as viruses and parasites. Antibiotics may have side-effects and their unnecessary use may lead to problems with drug resistance.

Having said that, there are a few cases where antibiotic prophylaxis may be recommended. For example for people with compromised immune systems, such as those with HIV infection or those taking immunosuppressive drugs, or for people who are at increased risk of developing complications, such as people with Crohn's disease, ulcerative colitis, an ileostomy or colostomy, etc. In such cases, ciprofloxacin is usually the antibiotic used.

So far, there is not enough evidence to recommend probiotics for the prevention of traveller's diarrhoea.