Diseases & Conditions
Giardiasis is a diarrheal illness caused by a microscopic parasite, Giardia intestinalis. Once a person or animal has been infected with Giardia, the parasite lives in the intestine and is passed in feces. Because the parasite is protected by an outer shell, it can survive outside the body and in the environment for long periods of times (i.e., months).
During the past two decades, Giardia infection has become recognized as a common cause of waterborne disease in humans in the United States. Giardia can be found worldwide and within every region of the U.S. Anyone can get giardiasis; however, persons most likely to become infected are:
- Children in child care settings, including diaper-aged children
- Close contacts or caregivers of infected people
- People who drink water or use ice made from contaminated sources (e.g., lakes, streams)
- Backpackers, hikers and campers who drink untreated or insufficiently treated water or who do not practice good hygiene (e.g., proper hand washing)
- People who swallow contaminated water while swimming, especially in lakes, streams, rivers, springs and ponds
- International travelers
- People exposed to human feces through sexual contact.
Signs & Symptoms
Giardia infection can cause a variety of intestinal signs or symptoms, which include diarrhea, gas or flatulence, greasy stools that tens to float, stomach or abdominal cramps and upset stomach or nausea. These symptoms can lead to weight loss and dehydration, although some people with the infection has no symptoms at all.
In otherwise healthy persons, symptoms of giardiasis may last two to six weeks, sometimes lasting longer. Medications can help decrease the amount of time symptoms last.
If you think you have giardiasis contact your health care provider. To diagnose an infection your health care provider will likely ask you to submit stool samples to check for the parasite. Giardia can be difficult to diagnose, so your provider may ask you to submit multiple stool specimens collected over a few days.
The Giardia parasite lives in the intestine of infected humans or animals (e.g., cats, dogs, cattle, deer and beavers). Millions of germs can be released in a bowel movement of an infected human or animal. Giardia is found on surfaces or in soil, food, or water that has been contaminated with the feces from infected humans or animals.
You can become infected after accidentally swallowing the parasite; you cannot come infected through contact with blood. Giardia can be spread by:
- Accidentally swallowing Giardia picked up from surfaces (such as bathroom fixtures, changing tables, diaper pails, or toys) contaminated with feces from an infected person or animal.
- Drinking water or using ice made from contaminated sources.
- Swallowing recreational water contaminated with Giardia. Recreational water includes water in swimming pools, water parks, hot tubs or spas, fountains, lakes, rivers, springs, ponds or streams that can be contaminated with feces or sewage from humans or animals.
- Eating uncooked food contaminated with Giardia.
- Having contact with someone who is ill with giardiasis.
- Traveling to countries where giardiasis is common and being exposed to the parasite as described in the bullets above.
The Centers for Disease Control and Prevention give simple tips to prevent a Giardia infection.
Practice good hygiene:
Wash hands thoroughly with soap and water after using the toilet and before handling or eating food, after changing a diaper or assisting with tioleting, especially if you are caring for diaper-aged children, even if you are wearing gloves.
Wash hands thoroughly after touching something that could be contaminated (such as a trash can, cleaning cloth, drain or soil) and after handling animals or their toys, leashes, or feces.
Protect others by not swimming if you are experiencing diarrhea or for one week after your diarrhea stops. This is essential for children in diapers.
Shower with soap and water before entering recreational water. Wash children thoroughly, especially their bottoms, with soap and water after they use the toilet or their diapers are changed and before they enter the water.
Take children on frequent bathroom breaks or check their diapers often and change diapers in the bathroom or a diaper-changing area to keep Giardia and other germs out of pools, hot tubs, lakes, rivers, etc.
Avoid water that may be contaminated.