Traveller’s diarrhoea: the A's, anti-B's, and C's

By Dr Eddy Bajrovic*

Until fairly recently, Aussies travelling overseas routinely took antibiotics for traveller’s diarrhoea – even if it was relatively mild.
In fact, taking a precautionary course of antibiotics to prevent diarrhoea wasn’t uncommon.
This cautionary approach was understandable: as many as half of all travellers visiting a developing country for a 2-week stay will experience it to some degree, according to the CDC.
And, no-one wants their holiday plans disrupted by diarrhoea, right?
But, these attitudes have changed because more and more travellers who’ve used antibiotics to treat TD overseas are returning home ‘colonised’ with multi-drug resistant bacteria, such as MRE (Multidrug-resistant enterobacteriaceae) and ESBL-PE (extended-spectrum beta-lactamase–producing Enterobacteriaceae). 

Drug-resistant bugs to the fore

Why is it happening?
Antibiotics can ‘knock out’ the beneficial bacteria in our lower intestine, allowing bacteria not affected by the drugs to take their place.
Recent findings suggest that travellers who take antibiotics to treat diarrhoea are at particular risk of becoming ‘colonised’ with these resistant bacteria when they consume contaminated food and beverages during their stay.
These infected travellers can continue to shed drug-resistant organisms for months after they return home. If they were to start a local infection – especially in a hospital – it could have disastrous consequences for the nation’s public health. 
Two things have now become clear:
– While there is still a place for travellers to use antibiotics to treat more severe traveller’s diarrhoea, a more considered approach is needed.
– More than ever before, Australian travellers need to take measures to avoid getting the bugs that cause diarrhoea.

South Asia now high-risk region

The incidence of drug-resistant bacteria is growing alarmingly worldwide, with rates highest in South Asia – a popular holiday region for Australians. According to the Finnish study mentioned above, around 80% of travellers visiting South Asia who got diarrhoea and self-treated with antibiotics became colonised with drug-resistant organisms. 
Our advice to travellers now is:
DON’T TAKE ANTIBIOTICS if the symptoms are only mild or even moderate. Instead, drink plenty of safe water, along with rehydration fluid such as Gastrolyte, to restore the body’s electrolyte balance and maintain hydration. In all likelihood your body will eliminate the TD-causing bug naturally within 2-3 days.
DO TAKE ANTIBIOTICS if you have fever above 38°C, cramps causing severe pain, or blood in your bowel motions. In short, only take them when you are REALLY sick with traveller’s diarrhoea.
A traveller’s age, general health (i.e. chronic conditions, allergies), and the type of bacterial resistance known to exist at their destination all need to be factored in determining the correct antibiotics for treating TD. (There are several choices that are right for different regions of the world – discuss which is best for you and your destination during your pre-travel medical.)

There’s no TD vaccine, but…

Unfortunately, there is no vaccine to prevent traveller’s diarrhoea.
However, the oral cholera vaccine, Dukoral has been shown to reduce the incidence of diarrhoea caused by enterotoxigenic E coli, which causes around 20% of TD cases in developing countries. 
This makes Dukoral a prevention option for those travellers at higher risk of TD – particularly those visiting India. (Experts say a significant proportion of TD cases among travellers visiting India are actually mild cholera infections that have simply not been diagnosed.)
Antimotility or ‘stopper’ drugs like Imodium and Lomotil can relieve cramp and diarrhoea. But, it’s important to understand that stoppers don’t eliminate TD-causing organisms.
They should be used for mild diarrhoea only and for no longer than 48 hours.
Stopper drugs should NOT be given to: someone with a fever over 38°C or with blood in their stool, a child under 6 years, or a pregnant woman.

Self-treatment – what to do, and when

Replacing fluids lost through diarrhoea and maintaining your energy levels is all-important.
FLUIDS – Dehydration is not an issue for most adult travellers with mild TD and maintaining regular intake of (safe) fluid intake is enough to ensure adequate hydration. Milk or milk-based products can worsen symptoms, while caffeine and alcohol contribute to dehydration – all are best avoided.
However, children – especially infants under 2 years – can dehydrate rapidly and oral rehydration solution (ORS) such as Gastrolyte should be used to replace lost fluid and electrolytes (in small sips if the child is vomiting). Parents should seek medical advice if a child becomes seriously dehydrated or if diarrhoea lasts for more than 24 hours. Read more
FOOD – Food intake is also important to maintain energy levels and heal the bowel. Select high-carbohydrate foods such as rice, bananas, potatoes and dry biscuits or crackers. Again, children need special consideration: infants should continue breast feeding or taking solid food, while for older children multiple small meals of high-carb food are better than the usual larger meals. Read more
diarrhoea treatment kit should include a 'stopper', a course of antibiotics, a thermometer, and an Oral Rehydration Solution (for children & those at higher risk of TD). (For longer stays, especially to remote areas, an anti-parasitic medication should be included for the treatment of diarrhoea caused by a parasite, such as Giardia.)

Make smart food, beverage choices

Given the rising incidence of drug-resistant bacteria, preventing TD is more crucial than ever. Reducing the risk of infection is all about making safer choices with food and beverages, as well as consistent personal hygiene.
CHOOSE FOOD… that’s fresh and has been thoroughly cooked and served steaming hot. Look for popular local dishes in a busy restaurant, rather than low-turnover meals. Eat only fruit and vegetables that you can peel or cut open yourself. Uncooked leafy vegetables and salads may have been grown in or washed in contaminated water and are best avoided. Bread and other dry foods don’t support bacterial growth well and are generally safe.
AVOID FOOD… cold or re-heated food (i.e. hamburger patties are often pre-cooked and sit in the open air at room temperature); Dishes that require a lot of handling or preparation, or may have been in contact with insects or animals; Shellfish, prawns and meat that has not been thoroughly cooked. (It’s often safer to avoid shellfish and prawns completely – ice can be problematic and even well-cooked oysters can transmit hepatitis A virus and noroviruses.)
CHOOSE BEVERAGES… from bottles or cans – without ice. Drink tap water only after you’ve first boiled or treated it. As mentioned in a recent article, isthewatersafetodrink is a new website that tells travellers if the tap water is safe – and not - at their destination. 
AVOID BEVERAGES… like milk, ice-cream, yogurt drinks and other milk products (including cheeses), unless you’re sure they’ve been made with pasteurised or boiled milk. Freshly squeezed fruit juice from street stalls is best avoided, too: It’s often made or stored in hard-to-clean equipment and bulked up with tap water.

* Dr Bajrovic is the Medical Director of Travelvax Australia.

Find out more about traveller’s diarrhoea and safe food and hygiene from the Travelvax Australia website, or by calling our free travel health advisory service on 1300 360 164. You can also obtain a TD treatment kit that’s right for you and your destination during a pre-travel medical consultation at a Travelvax clinic.