Travellers

 

Travel Health Information Sheets
 

Updated May 2011

Giardiasis

Giardia cyst photograph courtesy of Centers for Disease Control and Prevention (CDC)

What is giardiasis?

Giardiasis is a type of diarrhoea caused by a parasite called Giardia intestinalis. You get giardiasis by eating food or drinking water contaminated with the parasite cysts. After you swallow the cysts, they release another form of Giardia, called the trophozoite. This causes symptoms inside your intestines. Giardiasis can also be acquired by swallowing contaminated water during swimming or from another person when hygiene is poor.

What are the symptoms?

  • Diarrhoea

  • Bloating

  • Cramps

  • Increased, flatulence (wind) with a foul odour

  • Nausea and loss of appetite

  • Stomach ache

  • Weight loss

Diarrhoea may not begin until a week or two after you have ingested the cysts and can last for several weeks. Without treatment, giardiasis can stop you absorbing food properly, causing weight loss.

What is my risk?

Giardiasis is found everywhere in the world, including the UK. In travellers, it is usually acquired when access to clean food and water is poor. Countries in Asia, such as India and Pakistan, are the most common places where travellers and tourists get giardiasis.

How do I reduce my risk?                                   

Follow strict food and water and personal hygiene advice. This includes brushing your teeth with bottled, rather than tap water, in risk areas. Hand washing, particularly after using the toilet or changing a baby’s nappy, is very important.

Try not to swallow water when swimming, even in a pool, as Giardia cysts are not always killed by chlorine.

Avoid exposure to other people’s faeces, including during sexual contact.

Is there a vaccine?

There is no vaccine to prevent giardiasis.

Can giardiasis be treated?

Giardiasis can be treated with drugs used to kill parasites, usually metronidazole or tinidazole. It is very important not to drink alcohol when you are taking these drugs, as this causes nausea and vomiting.

If you think you might have giardiasis, see your GP as soon as possible. In some cases a referral to a travel medicine or infectious diseases doctor is appropriate; Giardia cysts can be spotted by looking at stool samples through a microscope or by other specific tests.

To stop spread of infection, practice good personal and household hygiene, including washing clothes in hot water and cleaning your bathroom and kitchen carefully.

Links

Health Protection Agency: Giardia.

NHS Choices: Giardiasis

Photographs of Giardiasis trophozoites and cyst courtesy of CDC