About Us  |  Contact Us  |  Español
Care New England Health System
cne_uplefticon
Care New England
 
    Health Library
    Find A Doctor
Search by Last Name
Search by Specialty
Search by CNE Affiliation*
Search by Keyword
 
Limit Search Results By
Gender
Languages

Giardiasis

Definition

Giardiasis is a gastrointestinal infection. It is one of the most common parasitic diseases in the world.
Gastrointestinal System
The Intestines
Copyright © Nucleus Medical Media, Inc.

Causes

Giardiasis is caused by a tiny parasite. Giardia cysts are a resistant form of the parasite that can survive outside a human or animal body. These cysts cause the spread of this disease. For infection to occur, a person must ingest Giardia cysts by mouth. After cysts are ingested, the parasites start growing and multiplying in the small intestine. Ingesting as few as ten parasitic cysts can cause an infection.
Giardiasis can occur by:
  • Contact with feces containing the parasitic cysts. Infected feces can be:
    • Human
    • 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

Risk Factors

Factors that increase your risk of getting this disease include:
  • 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

Symptoms

Symptoms usually start 5 to 28 days after infection. Not all people who are infected have symptoms. However, all people who are infected can transmit the disease.
Symptoms may include:
  • Diarrhea
  • Loose, greasy, foul-smelling stools
  • Abdominal pain or cramps
  • Bloating
  • Gas
  • Nausea or vomiting
  • Weight loss
  • Mild fever—rare

Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam will be done.
Your bodily fluids, tissue, and waste products may be tested. This can be done with:
  • Stool tests
  • Fluid or tissue samples taken from the intestine
If you are diagnosed with giardiasis, everyone living in your household should be tested for the infection as well.

Treatment

Giardiasis is treated with a prescription antiparasitic drug. The medication is usually given for 5 to 10 days.
This condition may be resistant to medications. This may make treatment difficult. It may also mean that you may be sick longer.

Prevention

Follow these guidelines to prevent getting or spreading giardiasis:
  • Maintain good personal hygiene.
  • Wash hands several times a day, especially:
    • Before eating or preparing food
    • After a bowel movement
    • After changing a diaper
  • When camping:
    • 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.

RESOURCES

American Academy of Family Physicians http://www.familydoctor.org

National Institute of Allergy and Infectious Diseases http://www.niaid.nih.gov

CANADIAN RESOURCES

The Canadian Association of Gastroenterology (CAG) http://www.cag-acg.org

Public Health Agency of Canada http://www.phac-aspc.gc.ca

References

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.

Revision Information

Care New England Health System
© 2011 Site Index | Disclaimer | Legal Notices