raveller’s diarrhoea (TD) is a general term applied to the common problem of diarrhoeal illness experienced by travellers, usually in the first week or two of a stay in a foreign environment.

Traveller’s diarrhoea particularly affects those who travel from industrialised countries to developing countries, especially tropical and semi-tropical destinations. Other than geography, other risk factors for acquiring these infections include age (less than six years), genetics, use of acid-blocking medications and nature of travel.

Certain types of trips carry higher risk – e.g., cruise ship holidays, holiday resorts, backpacking etc. Traveller’s diarrhoea remains a major public health problem with significant morbidity.

TD is an abdominal infection that can result from a variety of intestinal pathogens. Bacteria are the predominant and account for 80 percent of cases. Globally, escherichia coli are the most common bacterial cause. Campylobacter jejuni and salmonella and shigella species also frequent culprits. Rota-viruses and noro-viruses are also common causes. Protozoa such as giardia lamblia or cyclospora spp are more likely to cause persistent diarrhoea (lasting over two weeks).

How do these germs present clinically?

Bacterial and viral TD present with sudden onset of bothersome symptoms that can range from mild cramps and urgent loose stools to severe abdominal pain, bloody diarrhoea, fever, and vomiting. Bloody diarrhoea (dysentery) occurs more commonly with some pathogens (salmonella, shigella and campylobacter species). Some pain may accompany infection with campylobacter spp. Diarrhoea caused by entero-toxigenic e-coli is usually watery and profuse. It may be preceded by abdominal pains, nausea and general malaise.

Should tests be ordered?

An investigation may be required if the traveller’s diarrhoea persists for more than 14 days or earlier if there is blood in the stool, fever or severe illness. Stool culture, including microscopy, culture and sensitivity and tests for ova, cysts and parasites, are recommended. Also, blood tests: FBC, U&Es, LFTs, ESR and CRP may be required.

How should one manage this infection?

Untreated, bacterial diarrhoea usually lasts three to seven days. Viral diarrhoea generally lasts two to three days. Untreated, protozoal diarrhoea can persist for weeks to months. The patient must see a physician for timely management with antibiotics.

Replacement of fluid losses is key to diarrhoea therapy and helps the traveller feel better more quickly. For severe fluid loss, replacement is best accomplished with oral rehydration solution (ORS) prepared from packaged oral rehydration salts (e.g., those provided by the World Health Organisation). ORS is widely available at stores and pharmacies.

Traveller’s diarrhoea remains a major public health problem with significant morbidity.

ORS is prepared by adding one packet to the indicated volume of boiled or treated water, which is one litre.

In patients at risk of worsening dehydration with severe symptoms or with other risk factors (the young, the elderly, those with immunosuppression or other co-morbid conditions), hospital admission should be considered.

Children younger than one year of age, with more than five stools or more than two vomitings in the past 24 hours, need admission. Also, children who have stopped taking breastfeed or are malnourished must be hospitalised.

Can antimotility drugs be used during illness?

Symptomatic treatment may be needed for logistical reasons, particularly while travelling. Loperamide or bismuth subsalicylate may also be used in mild cases only (not recommended for children). Neither should be used alone if the stool contains blood or mucus or if there is fever, and these should be used with antibiotic cover after consulting a physician only. Anti-motility medication is not recommended for children.

What are the possible complications?

TD can be disruptive to people travelling for whatever reason, whether for holiday or business. Complications associated with dehydration may occur in severe cases. Other unusual sequelae include toxic megacolon, hepatic abscess, sepsis and bowel perforation. Post-infectious irritable bowel syndrome (IBS) occurs in up to 30 percent of cases.

What are the prevention measures?

Carefully washing hands with soap whenever available is the mainstay. When hand washing is not possible, small containers of hand sanitiser containing 60 percent alcohol can make it easier for travellers to clean their hands before eating. Only bottled or boiled water must be used for ice cubes, brushing teeth and washing food. Undercooked food and raw seafood must be avoided. Vegetables and fruits must be peeled before consuming them. Ice creams should be avoided unless from a reliable source. Consuming food from markets or buffets, which has been out for some time, must be avoided.

Is there any role of vaccination in the prevention of TD?

The typhoid vaccine is currently the only one routinely recommended for travellers. Vaccines against entero-toxigenic e coli are in development and are a World Health Organisation (WHO) priority.

Stand-by antibiotics

These may be helpful for some people travelling to high-risk or medium-risk countries to have a supply of “in case” antibiotics to take should they develop traveller’s diarrhoea. This may be particularly helpful for those who are going to be in remote areas with poor sanitation and a lack of access to healthcare or for those who are trekking or travelling continually. Also, very helpful for those travelling to Western countries where, unlike Pakistan, antibiotics are not provided over the counter, and a physician has to be consulted through a proper channel. A short course of antibiotics is known to reduce the length of the illness. A physician must be consulted to advise appropriate antibiotics depending on the destination area, individual age, pregnancy status and overall health status.

The writer [MBBS, FCPS, MRCGP(INT)] is a consultant in family medicine at Al-Khidmat Raazi Hospital, Islamabad