By Dr Eddy Bajrovic*
If you were to examine the surface of some types of fruit and vegetables through a microscope you’d see a maze of cracks and crevices.
Invisible to the naked eye, these tiny trenches are perfect places for germs to become trapped and multiply.
We’ve seen just how effective contaminated salad vegetables can be at causing food poisoning over the past week. As of Monday, 92 people had been made ill by salmonella across Australia after eating pre-packaged leafy salad mixes, with more expected.
Although the outbreak is still under investigation, food industry experts believe it’s linked to either contaminated fertiliser (from chickens), or to the water that was used to irrigate the crop or wash the lettuce before it was bagged at Tripod Farms in Victoria.
Salmonella is an increasingly common cause of food poisoning in Australia. There were just over 17,000 lab-confirmed cases here last year – the highest tally in 25 years. Many milder cases are not recorded at all.
Worryingly, strains of the bacterium are becoming increasingly resistant to antibiotics.
WHO study confirms global increase
New data from the World Health Organisation (WHO) confirms that it’s never been more critical to make safe food choices when travelling overseas. The WHO recently released the first-ever study of the global burden of food-borne diseases, ‘Estimates of the Global Burden of Food-borne Diseases’.
The study examined the potentially devastating impact of eating food contaminated by 31 agents, including bacteria, viruses, parasites, toxins, and chemicals. It found that:
- Almost 1-in-10 people fall ill every year from eating contaminated food and 420,000 die as a result.
- Children under 5 are at particularly high risk, with 125,000 youngsters dying from food-borne diseases every year.
- The highest burden of food-borne diseases is in Africa and South-East Asia, which is a favourite holiday destination for Australians.
The WHO researchers found that diarrhoeal diseases are responsible for more than half of the global burden of food-borne illnesses. Each year an estimated 550 million people fall ill and around 230,000 die, with kids under 5 accounting for 220 million cases and 96,000 deaths.
Travellers often at higher risk
Food can get contaminated in many ways. While fertiliser or water can be to blame, it may also be the result of poor hygiene by the people who picked the produce, processed it in a factory, or prepared it in a kitchen or at a street stall.
That’s why international travellers are at much higher risk when visiting a developing country. During a stay of up to 2 weeks, more than 6-in-10 people will experience traveller’s diarrhoea (TD), according to an earlier study of returned travellers.
Traveller’s diarrhoea can be caused by eating raw or undercooked meat, eggs, fresh produce, and dairy products contaminated by norovirus, Campylobacter, non-typhoidal Salmonella and pathogenic E. coli.
Other major contributors to food-borne diseases worldwide are two vaccine-preventable diseases, typhoid fever (Salmonella typhi) and hepatitis A, as well as the tapeworm, Taenia solium, and aflatoxin, which is produced by mould on grain that hasn’t been stored properly.
Think twice before ordering
Yet TD-causing germs are typically transmitted in water. That should hardly be surprising if the local water supply is untreated and there’s no sewerage system.
Of the world’s 7.4 billion people, more than 1 billion people don’t have toilets and defecate in the open.
Viruses, protozoa, bacteria, and intestinal parasites can all cause TD. Even very small amounts of Giardia and Shigella are enough to make a person sick, making them two of the most commonly diagnosed post-travel diseases among Australian travellers
For Aussies visiting developing regions like Asia, Africa, Pacific or Caribbean islands, and Central or South America, dodging these diarrhoea-causing infections means thinking twice about choices they wouldn’t think twice about at home.
Simple steps to reduce risk
The safest approach is to:
- Avoid leafy salads and fruit that can’t be peeled – regardless of how fresh and inviting they may appear on the buffet table.
- Presume all tap or well water is contaminated. Drink only safe water that has come in a sealed bottle or has been boiled, purified, or chemically disinfected.
- Remember to say ‘No ice, please’. Freezing doesn’t kill germs in the water, it just preserves them.
Cleaning your hands regularly – especially after using the toilet and before eating – using soap and water or an alcohol-based hand sanitiser is one of the most important ways of preventing illness at home or away.
As careful as you might be, dodgy food and water can be hard to avoid.
Smart travellers always carry a diarrhoea treatment kit, which should include a 'stopper' drug, 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.
Learn more about avoiding and treating TD, including how (and when) to use antibiotics, what to eat and drink (and not), and how to manage and recover from TD quickly.
* Dr Bajrovic is Medical Director of Travelvax Australia.
Get more advice on healthy travel for your next overseas trip by calling our travel advisory service on 1300 360 164 (toll-free from landlines). Our experienced medical professionals can also advise you on vaccinations and medication to consider during a pre-travel consultation.