Travellers' diarrhoea

Traveller's diarrhoea is a common illness affecting up to 50% of international travellers. The condition is usually self limiting. When investigated, the majority of infections are caused by bacteria. The most commonly found pathogen is Escherichia coli (enterotoxigenic and enteroaggregative species) whilst Salmonella, Shigella and Campylobacter, all invasive bacteria, form the second largest group of pathogens. Viral infections are discovered in a smaller proportion of cases, but this may be due to lack of investigation. Persisting diarrhoea is frequently caused by protozoa and occasionally helminths. Those suffering with severe acute gastroenteritis should be assessed and treated for dehydration. Empirical treatment is often with fluoroquinolones, although resistant strains are increasingly common. Loperamide is offered for symptomatic treatment if there is no fever or dysentery. Persistent diarrhoea should be fully investigated and treated. Important non-infectious problems can be unmasked by an initial diarrhoeal illness or present during travel.