Most cases of traveller’s diarrhoea are thought to be caused by eating food or drinking water that has been contaminated by bacteria, a virus or a parasite.
A wide range of organisms can cause traveller’s diarrhoea, including:
- salmonella – bacteria found in raw meat and poultry and dairy products
- campylobacter – bacteria found in raw meat and poultry, unpasteurised milk and unclean water
- shigella – bacteria found in undercooked or raw food and spread through poor hygiene
- giardia intestinalis – a parasite found in contaminated water and spread through poor hygiene
- cryptosporidium – a parasite found in contaminated food and water
High-risk foods
Food can become contaminated if:
- it is handled by people who have not washed their hands after going to toilet
- it is not properly cooked or refrigerated
- cooked food is allowed to come into contact with raw food
Food that is most at risk of contamination includes:
- raw seafood
- undercooked meat or poultry
- food from buffets, markets and street vendors
- food from restaurants when you are uncertain if it has been properly cooked or refrigerated
- food that contains raw or uncooked eggs (such as homemade mayonnaise)
- unpeeled fruit and vegetables
- ice cream
High-risk drinks
If you are travelling in a high-risk area for traveller’s diarrhoea, it is safer to assume that most sources of water, such as tap water, wells, rivers and lakes, are not safe to drink.
Stick to sealed bottled water, sealed fizzy drinks or drinks that you know have been boiled, such as tea and coffee.
Also, it is usually a good idea to avoid having ice in your drinks.
High-risk activities
Some types of holiday and activities increase your chances of having an episode of traveller's diarrhoea. For example, trekking or camping may increase your risk because you may not have access to clean water.
Being a passenger on a cruise ship also increases your risk. Poor hygiene could affect a large number of people, and being in close proximity to many others makes it easier for a virus or bacteria to spread.
High-risk areas of the world
A recent report from the Health Protection Agency summarised the potential risk of getting traveller’s diarrhoea depending on where in the world you were travelling to. They identified:
- low-risk areas where your risk of getting traveller's diarrhoea is less than 1 in 14 – Western Europe, North America, Japan, Australia and New Zealand
- medium-risk areas where your risk of getting traveller's diarrhoea could be as high as 1 in 5 – Eastern and Southern Europe, Russia, Israel, South Africa and some islands in the Caribbean
- high-risk areas where your risk of getting traveller's diarrhoea is higher than 1 in 5 and could be as high as 1 in 2 – Africa, Central and South America, the Middle East and most of Asia
