Contaminated food and water can spread a number of different infectious diseases such as cholera, hepatitis A, travellers’ diarrhoea and typhoid. Travellers’ diarrhoea is particularly common in those visiting low-income countries.

Chemical contamination of water supplies can also be a risk.

It can be difficult to avoid contaminated food and water, but travellers can try and reduce their risk by following the steps below.

A TravelHealthPro factsheet on travellers’ diarrhoea is available. This includes information on how to manage symptoms and when to get medical help.

Certain travellers need to take particular care, as they are at increased risk of complications. This includes older people, those with a weak immune system, young children and those taking medication to reduce stomach acid.

Occasionally travellers experience illness from ingesting toxins from fish and other seafood.

For more in depth advice visit

https://travelhealthpro.org.uk/factsheet/44/food-and-water-hygiene

Water and other drinks

Drinks served in unopened, factory produced cans or bottles with intact seals such as carbonated drinks, commercially prepared fruit drinks, water and pasteurised drinks generally can be considered safe. Drinks made with boiled water and served steaming hot, such as tea and coffee are also usually safe.

In countries with poor sanitation, it is not advisable to drink tap water or use it to brush teeth, unless it has been treated. Ice should also be avoided. Water can be disinfected by bringing it to a rolling boil . Although boiling is a reliable method of disinfection, it may not always be convenient.

Safe commercial chemical treatments can be used to disinfect water.

Using a water filter that has a filter size of ≤0.2 µm to 1.0 µm, before using a chemical disinfectant is helpful, as water filters can remove suspended matter (dirt/dust specks) and parasites, if they work correctly .

Portable, battery-operated devices using UV light can be used to disinfect water. However, water must be free of dirt or dust particles or other material before treating. This method may not be practical if large quantities of water need disinfecting.

Travellers to areas with known unsafe or contaminated water supplies should:

  • rely on treated, filtered or bottled water
  • store water safely – keep drinking water in clean, covered containers to prevent additional chemical leaching

Natural mineral water is usually not recommended for infant feeds. As bottled water is usually not sterile, it should be boiled, like tap water, to at least 70°C and allowed to cool before mixing with the formula in preparation for a feed.

Food

Recently prepared, thoroughly cooked food that is served piping hot, fruit that can be peeled by the traveller (such as bananas and oranges) and pasteurised dairy produce such as yoghurts, milk and cheese are good options for travellers.

Travellers should:

  • wash and peel produce in clean water – rinse fruit and vegetables thoroughly to reduce pesticide residues; peel or cook when possible.
  • trim fat from meat and choose lean options – many chemical contaminants (like dioxins) accumulate in fat tissue.
  • diversify their diet – eating a wide variety of foods lowers the chance of repeated exposure to a single chemical source.

Certain foods are prone to contamination with pathogens (bugs) that can cause TD and should be avoided:

  • salads
  • uncooked fruit and vegetables
  • fresh or cooked food that has been left uncovered in warm environments, exposed to flies, such buffets
  • unpasteurised dairy products, like milk, cheese, ice cream and yoghurt
  • raw or undercooked meat, fish or shellfish, including oysters
  • food from street traders, unless thoroughly cooked in front of the traveller and served hot on clean crockery

Reducing the risk of marine poisoning

Travellers should avoid eating pufferfish and other high-risk fish such as barracuda, moray eel and other reef fish .

Shellfish poisoning is more likely to occur during or shortly after algal blooms, which may be referred to as ‘red tides’ or ‘brown tides’. Travellers should take notice of any posted warnings on this. Ideally, those visiting regions where food and water controls may not be adequate should avoid eating any shellfish, as they can also be contaminated with bacteria and viruses .

Unfortunately, marine toxins cannot be destroyed by cooking.