Introduction

Travellers’ Diarrhoea (TD) is a common and unpleasant illness, usually caused by bacterial infection of the gastrointestinal tract. Viruses cause about 10-20% of cases, and parasites are an unusual cause. The principal source of contamination is food. Drink may also be contaminated, and poor personal hygiene is also a significant source. As well as significantly disrupting travel plans, TD can also have serious long term complications.

 

How common is it?

It is estimated that 40% of the 50 million people travelling from industrialised countries to low income countries each year get TD. It most frequently occurs during the first week of travel, although it can occur at any time during the trip, or on return home - some causative agents have incubation periods of two weeks or more.

 

Are travellers and/or expat workers at risk?

Yes. Travellers and expat workers are at risk. The causative agents of TD are enteric pathogens that normally reside in faeces. If you consume faecally-contaminated material you may become ill.

 

What is the illness?

TD is usually sudden in onset and is characterised by the passage of 7-13 watery, loose stools over a period of 2 days, accompanied by one or more additional gastrointestinal symptoms such as nausea, vomiting, abdominal cramps, bloating or poor/absent appetite. It is usually self-limiting and lasts, on average, for 4 days.

 

There is a risk of developing long-term complications such as post-infectious irritable bowel syndrome (PI-IBS) and inflammatory bowel disease. Approximately 3-10% of those who develop TD will subsequently develop chronic abdominal complaints or PI-IBS, and there is evidence that 50-75% of the PI-IBS cases will persist for many (at least 5-6) years. 

 

Can it be treated?

Most cases of TD are mild, and only oral rehydration is required until symptoms resolve. Initial rapid rehydration aims to replace the fluid that has been lost. You should drink frequent, small volumes over 3 to 4 hours, consuming 200-400 ml of rehydration solution (such as Dioralyte™) for each vomit or loose stool. Once you are adequately hydrated you should maintain your hydration with normal fluids, compensating for further losses by consuming 200-400 ml of rehydration solution for each further vomit or loose stool.

 

Loperamide (Imodium®) is a drug that reduces gut motility. It can be used to control symptoms, and studies have shown that it may also shorten the course of disease. The notion that it may prolong the course of disease by preventing the body’s elimination of the infection is not supported by scientific evidence. Treatment with antibiotics shortens the course of disease by about one day, and also reduces the severity of symptoms. Antibiotics should only be prescribed to the patient by a doctor. Many travellers approach their doctor in advance for a supply of antibiotics which they can use should they contract TD. The combination of antibiotics with loperamide has been shown to be safe, and provides rapid relief of symptoms in addition to the curative effects of the antibiotics. Moreover, research has shown that a combination of loperamide and antibiotics provides a faster cure of TD than antibiotics alone.

 

Prevention

You can reduce your risk of TD by avoiding high risk foods, such as:

• raw fish and shellfish

• raw or undercooked meat

• moist, cold or raw items remaining for periods of time at room temperature before consumption (e.g. table sauces, buffet items)

• tap water, even in hotels claiming to treat it

 

The following are lower risk:

• food served steaming hot that looks, smells and tastes good

• food or drink that has reached 60°C (a temperature that inactivates the bacterial pathogens)

• food that has been peeled or well washed in clean water

• food prepared by the traveller in his/her own room or apartment

• carbonated drinks where the bottle’s seal is intact until immediately before consumption

 

Impeccable standards of personal and food hygiene (especially hand washing) can help prevent spread of TD between members of a party.

 

Vaccines designed to protect against TD are undergoing clinical trials. Vaccines are available providing some protection against cholera and ETEC, one of the causes of TD. Some travellers - particularly those with underlying medical conditions - may be advised to take antibiotics to prevent TD, particularly if they are going on short trips.