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Coronavirus (Covid-19): service updates, support and health advice.


Giardiasis is an infectious illness which can be transmitted by contaminated food or water. Symptoms include watery diarrhoea, abdominal pain, wind, vomiting, fever, weight loss and constipation. These can last up to several weeks.


It is caused by microscopic parasites entering the body through the mouth usually from unwashed hands and infected food or drink.

Possible routes of the infection are;

  • eating food prepared by someone already suffering from Giardiasis
  • contact with streams or ponds
  • drinking unchlorinated water

How it is spread

It is spread from person to person. If an infected person does not wash his or her hands properly after going to the toilet their hands may be contaminated with the parasite. They can then pass the infection on, either by direct contact with other people or else indirectly, for example by preparing food that someone else then eats.


  • wash hands thoroughly after going to the toilet, before preparing or serving food or drink, after handling raw meat and vegetables and after handling pets or their food bowls. Use hot, soapy water and a nail brush
  • avoid swallowing water when participating in water sports
  • drink mains or treated water. Make sure that the water tank in your loft is covered to stop birds getting in. Drink bottled water if abroad
  • always wash fruit and vegetables. When abroad it may be safer to use bottled water to do this
  • take care when changing the nappies of infected babies
  • regularly disinfect toilets


Antibiotics are sometimes used to treat this infection.

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