Avoiding Contaminated Water which is a frequent source of infection. Most cities and large towns have large piped water systems but the water is only safe to drink if it has been fully treated and chlorinated. Even in areas where the tap water is safe to drink the level of chemical treatment may be sufficient to render it unpalatable to the United Kingdom traveller. To be entirely safe the following alternative means of sterilisation are available. Bring it up to a rolling boil and allow it to cool, prolonged boiling is unnecessary.
Disinfectants are often ineffective if the water is visibly cloudy.
Iodine is very effective. Sterotabs and Puritabs. These are chlorine based and are less effective against amoebic cysts than iodine. Bottled water and drinks are normally safe, especially fizzy drinks. Use safe water for brushing teeth and for washing vegetables or salad which are to be eaten raw.