Giardia is a highly contagious intestinal parasite that can enter the body through drinking untreated water containing the parasite or by coming into contact with contaminated fecal matter. The parasite is found in the intestinal tract and feces within the human body and can survive outside of the body for months at a time. The Giardia parasite is also found in animals and can be transmitted to humans though their fecal matter.
Symptoms of having the Giardia parasite include severe abdominal cramping, diarrhea, nausea, and increased flatulence. If a person is experiencing these symptoms and is known to have been in contact with untreated water or a person already infected, a stool sample will be ordered by a doctor to positively identify the Giardia parasite.
The Giardia parasite may be difficult to diagnose with one stool sample, so a series of stool samples may have to be ordered. This is because the small section of a bowel movement that is tested in a sample may not contain the particles shed from the intestinal tract which carry the Giardia. Because the parasite is not present in fecal matter on a consistent basis, one or even multiple negative samples do not guarantee that the Giardia parasite is not present in the body. Stool samples are generally done at home with a kit and instructions provided by the clinic or lab doing the testing. The samples are then brought to the lab for testing and diagnosis. If the stool sample or samples test negative but the symptoms persist, a doctor may order another series of stool samples for further testing or begin treatment of an assumed case of Giardia based on the persisting symptoms.
To avoid contracting the Giardia parasite, do not drink water from lakes, streams or wells that have not been treated. If caring for small children infected with the parasite, make sure to thoroughly wash hands with soap and water when changing diapers, helping with toileting or coming into contact with the rectal area for any reason. Barriers should be used during anal or oral sex with an infected person and proper hand washing should be performed after sex so that any fecal matter that may have been passed from one person to the other is not later ingested. Due to Giardia’s highly infectious nature, life span outside of the body and presence throughout the world, even taking every precaution may not prevent a person from contracting the parasite.