You read that correctly, there is a time and place for everything, including salad. This seemingly healthy dish can quickly become unhealthy or even dangerous when consumed overseas. Six Australian travellers learned this the hard way after having one on a holiday in Bali.

The five women and a man were belatedly diagnosed with a severe liver disease called fascioliasis, which is caused by ingesting a type of liver fluke worm called fasciola. These are often found on plants grown or washed in water; particularly water cress.

After eating their salads in Bali, all six developed a severe illness that lasted many months after their holiday. Several underwent invasive investigations involving surgery and one even had sections of their liver removed, after being misdiagnosed with cancer.

The fact that the majority of the patients were women was not a surprise to Dr Mel Figtree, an infectious diseases specialist at Sydney’s Royal North Shore Hospital.

“Women are more likely to choose a salad from the menu than men,” Dr Figtree said.

“Travellers don’t think twice about eating a salad because they’re a very familiar and healthy choice back home in Australia.

“A green salad looks so fresh and inviting anywhere that it’s hard to imagine that they could cause a problem while you’re on holiday.

“But, fascioliasis is just one of a number of potentially severe diseases associated with salads.”

Fascioliasis occurs in 50 countries, mainly in developing regions: an estimated 40% of Bali’s cattle are infected. In developed countries like Australia, cattle and other livestock ‘hosts’ are drenched to kill the parasites.

As fascioliasis is so rarely seen in Australia, it took between six and 12 months plus intervention by specialists to correctly diagnose and treat the six Bali patients.

Once a person becomes infected, they can be symptomless for a few days or a few months. Later on, they undergo two clinical phases: the first ‘acute’, the second ‘chronic’.

Due to the rarity of such cases and the long lag in the appearance of symptoms – usually well after the holiday – diagnosis is often complicated and delayed, and severely impacts the victim’s health.

In a developing country, it’s especially hard to know the safety of leafy salad vegetables and fruit that can be eaten without peeling.

“It’s very difficult to remove pathogens from all the tiny crevices on the surface of leafy salad vegetables or from certain fruit that has come into contact with contaminated soil or water”, Dr Figtree said.

“The tap water used to wash them in the kitchen may also be suspect – even in an upmarket hotel or resort.

“When holidaying in a developing country, the safest approach for travellers is to forgo leafy salads and  unpeelable fruit – even when they look fresh and healthy”.

For more information on treating and diagnosing liver fluke, see our article.