About Giardia

July 1st, 2007

Giardia food poisoning is caused by a parasite known as Giardia lamblia or Giardia intestinalis. Giardia is also a common cause of waterborne disease in the United States.

Symptoms of Giardia infection, or Giardiasis, may include stomach cramps, diarrhea, gas, belching, bloating, greasy stools, nausea or upset stomach. Symptoms may occur 1 to 2 weeks after infection, and usually last from 1 to 3 weeks. Weight loss and dehydration may also occur as a result of these symptoms. Some individuals with Giardiasis are asymptomatic, meaning that they do not exhibit symptoms.

Giardia infection occurs when an individual eats food, drinks water, or comes into contact with surfaces or objects contaminated by the parasite or its cysts (a dormant stage in which the parasite is resistant to many adverse environmental conditions allowing it to survive outside the body). Giardia lives in the intestines of infected people or animals, and is excreted in feces. Infection, therefore, is the fecal to oral route.

Common ways of contracting Giardiasis include: eating uncooked food contaminated with Giardia; swallowing contaminated recreational water (e.g., pools, spray parks, ponds) or drinking water; or putting objects or fingers in the mouth that have come into contact with the feces of an infected person or animal.

To diagnose Giardiasis, your doctor will ask you to provide a stool sample, which will be examined for the presence of the Giardia parasite. You may be asked to provide several samples since detecting the parasite, or its cysts can be difficult.

Entry Filed under: About Giardia