Travellers' diarrhoea, typhoid fever, cholera and hepatitis A can all be acquired by ingesting contaminated food or water. Travellers' diarrhoea occurs in up to a half of European travellers who spend three weeks or more in the developing areas of Africa, Latin America, the Middle East or Asia, even if they stay in good quality hotels. It should therefore be taken seriously.

The commonest organism associated with travellers' diarroea in tropical and subtropical areas is enterotoxigenic Escherichia coli, which may be part of the normal bowel flora of the local population. However, a range of bacteria, viruses and parasites are associated with the condition, including campylobacter, salmonella, shigella, and, especially in children, rotavirus. The main parasitic cause is Giardia lamblia.

5.2  Prevention

Spread is by the faecal-oral route, usually via food or water. Travellers can reduce the risk of disease by observing the precautions listed under 5.4.

5.3  Management of travellers' diarrhoea

Travellers' diarrhoea is usually a mild disease, though severe fluid and electrolyte disturbance may occur. Treatment is to replace fluid loss with a suitable oral solution; in severe cases parenteral replacement therapy may be required.

Travellers should preferably go prepared with commercial sachets of replacement sugar and salt which can be made up with freshly boiled or bottled water when needed. An alternative is to dissolve one teaspoon of sugar and a pinch of salt in a glass or mug (about 250ml) of freshly boiled or bottled water, flavoured to taste with fresh orange juice.

The sufferer should continue to eat what he/she feels like - food shortens the illness and lessens fluid loss.

Antimotility drugs may give symptomatic relief but should not be given to children or if there is fever.

Medical help should be sought if any one or more of the following occur:

•   there is blood in the faeces

•   the illness is accompanied by fever

•   the affected person becomes confused

•   the diarrhoea does not settle within 72 hours (24 hours for small children and the elderly)

Antibiotic prophylaxis is only occasionally appropriate for travellers' diarrhoea for those in whom the effects of the illness would be serious. Alternatively, for these travellers, antibiotics may be carried for immediate self treatment until medical help can be obtained.

In travellers without intercurrent disease, self therapy with antibiotics (e.g. ciprofloxacin) is not routinely recommended, although it may shorten the symptoms. If such medication is being prescribed it should be understood by the traveller that travellers' diarrhoea is essentially a self limiting disease, and whilst treatment is usually successful and trouble free, it could produce side effects, complicate the diagnosis and encourage the development of antibiotic resistance. A shortened course of ciprofloxacin is usually effective and should minimise the above disadvantages, but it should be remembered that extensive use of ciprofloxacin will mean it rapidly becomes ineffective worldwide. Ciprofloxacin should not be prescribed for children.

5.4  Rules for eating and drinking safely

Travellers should be reminded of the precautions they can take to eat and drink safely:

Eat and drink safely Always wash your hands after going to the lavatory, before handling food and before eating. If you have any doubts about the water available for drinking, washing food or cleaning teeth, boil it, sterilise it with disinfecting tablets or use bottled water - preferably carbonated with gas - in sealed containers. Avoid ice unless you are sure it is made from treated or chlorinated water. This includes ice used to keep food cool as well as ice in drinks. It is usually safe to drink hot tea or coffee, wine, beer, carbonated water and soft drinks, and packaged or bottled fruit juices. Food may be contaminated even though it looks, smells and tastes perfectly normal, so avoid:   salads   uncooked fruit and vegetables, unless you can peel or shell them yourself   food which has been kept warm   food likely to have been exposed to flies   dishes containing uncooked egg   ice cream from unreliable sources, such as kiosks or itinerant traders   shellfish, especially if uncooked   unpasteurised dairy produce   food from street traders unless you are sure it is freshly prepared and hot Eat freshly cooked food which is thoroughly cooked and still piping hot.