Giardia
What is Giardia?
Giardia is a parasite (germ) which, if swallowed, attaches itself to the upper intestine (gut) and may cause illness. The illness is called Giardiasis.
What are the symptoms of Giardia infection?
The commonest symptom is diarrhoea, which tends not to be too severe, but can last several weeks, or longer. The diarrhoea is often pale and very smelly.
The most common symptoms are:
• stomach cramps/pain/discomfort • bloating • feeling sick
• loss of appetite • wind • vomiting,
• loss of weight
Young children who are infected may just have poor appetite with poor weight gain. Some adults and children carry Giardia in their gut without any symptoms.
Where does Giardia come from?
It lives in the gut of humans and many wild and domestic animals. It is found in every country, but is more common where hygiene is poor. For this reason, many infections in the UK affect people who have recently travelled abroad.
How can I catch Giardia?
The commonest way to catch Giardia is to eat food or drink water that has become contaminated with human or animal sewage in some way. This is the usual way that travellers get infected.
People who carry Giardia, and who don’t wash their hands after going to the toilet, will contaminate their hands with the germ. They can then spread it directly to other people. This is often the case with young children in nurseries, creches or schools, and older people in institutions; infection can also spread within families in this way.
You can catch it while swimming. Swallowing contaminated water can cause infection. Swimmers who are infected with Giardia can contaminate swimming and paddling pools. Unfortunately the disinfectant used in swimming and paddling pools does not kill Giardia.
Giardia can also be spread by intimate sexual contact.
How will I know if I have Giardia?
If you have diarrhoea, or other symptoms described above, your doctor may ask you to provide a stool sample for testing in the Laboratory. The Giardia germ can usually be seen with a microscope. It may sometimes be difficult to see the germ, and therefore several stool samples may have to be examined.
How can I avoid getting Giardia?
1. Travellers, especially to Asia, Africa and South America, should avoid high-risk foods and drinks as far as possible:
• Avoid raw vegetables and salads, and fruits that cannot be peeled
• Avoid drinks with ice and ice cream.
• Sterilise tap water before drinking (eg boil, or use sterilising tablets), or drink carbonated bottled water.
• Be wary of food from street vendors.
• Choose food that is thoroughly cooked and piping hot.
2. Campers and Back-Packers, whatever country they are in, should sterilise river or spring water before drinking.
3. Swimming (except in the sea) carries a risk of Giardia – do not swallow water, especially if swimming outdoor pools/rivers/lakes etc.
4. Good hygiene in nurseries and playgroups is important at all times, as Giardia may be asymptomatic.
What special care should I take if I or my family, have Giardia?
You should wash your hands carefully with soap and water and dry them thoroughly each time you go to the toilet or change a nappy. This reduces the chance of passing the infection to other people. Children with Giardia
infection need to be supervised when washing their hands.
Do not go swimming or take your child swimming when they have diarrhoea, or for two weeks after the diarrhoea has stopped, as they may contaminate the water for other users.
How long should someone with Giardia stay away from work,school or nursery?
Most adults and children over five years should stay away from work until they are feeling better.
People working with food must stay off work until they have been symptom free for two days. You must tell your employer about your illness.
People working with vulnerable groups e.g. the young, elderly or those in poor health must stay off work until they have been symptom free for two days. You must tell your employer about your illness.
Young children should stay away from playgroups, childminders or nursery school until they have been symptom free for two days.
Who cares if I have Giardia?
Your GP and your local Environmental Health Officer care.
Your GP will give you advice about medical aspects of Giardia. You may also be contacted by someone from your local Environmental Health Department, to try and find out where you may have picked up the illness.
For further information and advice, please contact:
Department: Environmental Health Department
Phone 020 8547 5540
E-mail: jane.harmsworth@rbk.kingston.gov.uk
Address: Guildhall,Kingston upon Thames, Surrey, KT1 1EU
Website: www.kingston.gov.uk
Produced by SW London Health Protection Unit March 2003
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