Wherever you are in the world, be careful about what you eat and drink.

Food and water can contain infectious substances. This includes water in swimming pools, lakes, rivers and the sea, so try not to swallow water when you are swimming.

Helpful hints - how to avoid stomach upsets

• If you are not sure that drinking water is clean, sterilise it by boiling (at high altitudes boiling is not enough to sterilise water), or using a filtering system or disinfectant tablets.
• Use bottled water if you cannot ensure that drinking water is clean.
• Make sure that seals on bottled water are not broken.
• Avoid ice unless you are sure it is made from safe water.
• Eat freshly cooked food that has been thoroughly cooked and is still hot.
• Avoid uncooked food, unless you can peel or shell it yourself.
• Avoid food that may have been exposed to flies.
• Avoid ice cream from unreliable sources, such as kiosks.
• Avoid – or boil – unpasteurised milk.
• Be careful when eating shellfish – they may contain harmful bacteria.
• Avoid insect and animal bites.

In some countries, diseases can be spread by insects and ticks. Use insect repellents, (preferably one containing DEET – diethyltoluamide) and cover your arms and legs with appropriate clothing if you are walking, especially in grassy or wooded areas.

Animal bites can lead to infection, and may even cause death. It is important to be careful even with apparently tame animals. Rabies is present in many countries, including most of Europe and North America. If you are bitten, it is essential to see a doctor immediately for post-exposure treatment.