|Copyright © Nucleus Medical Media, Inc.|
Contact with feces containing the parasitic cysts. Infected feces can be:
- Animal such as cats, dogs, beavers, and cows
- Eating food, drinking water, or swimming in water contaminated by the parasitic cysts
- Contact with a person's hands that are contaminated with parasite cyst-infected stool
- Age group: young children and older adults
- Unsanitary or crowded living conditions
Drinking untreated water, such as:
- Well water
- Stream or lake water
Low stomach acid, often found in:
- Older adults
- People on ulcer drugs
- Oral-anal sex
- A weakened immune system
- Working or staying in a daycare center or nursing home
- International travelers
- Internationally adopted children, who may have more than one parasitic infection
- Hikers, campers, and swimmers
- Loose, greasy, foul-smelling stools
- Abdominal pain or cramps
- Nausea or vomiting
- Weight loss
- Mild fever—rare
- Stool tests
- Fluid or tissue samples taken from the intestine
- Maintain good personal hygiene.
Wash hands several times a day, especially:
- Before eating or preparing food
- After a bowel movement
- After changing a diaper
- Bring bottled water for drinking, cooking, and brushing teeth.
- Purify untreated water before using—boil, filter, or sterilize.
- Thoroughly wash or peel raw fruits and vegetables before eating.
When traveling overseas:
- Use only bottled water for drinking, cooking, or brushing teeth.
- Only eat food that is well cooked and served steaming hot.
- Do not let children with diarrhea go into swimming pools.
- Keep swimming pools properly chlorinated.
- Stay home from work until the infection is gone. Keep children home from school or daycare until the infection is gone.
American Academy of Family Physicians http://www.familydoctor.org
National Institute of Allergy and Infectious Diseases http://www.niaid.nih.gov
The Canadian Association of Gastroenterology (CAG) http://www.cag-acg.org
Public Health Agency of Canada http://www.phac-aspc.gc.ca
Adam RD. Biology of Giardia lamblia. Clin Microbiol Rev. 2001;14:447
Giardiasis. KidsHealth.org website. Available at: http://kidshealth.org/parent/infections/stomach/giardiasis.html. Updated September 2011. Accessed August 14, 2013.
Parasites–giardia. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/parasites/giardia/. Updated March 8, 2011. Accessed August 14, 2013.
Nash TE. Surface antigenic variation in Giardia lamblia. Mol Microbiol. 2002;45:585.
- Reviewer: Michael Woods, MD
- Review Date: 08/2013
- Update Date: 05/11/2013