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Beaver and Giardiasis

What is Giardiasis?

Giardiasis is a gastrointestinal infection caused by a microscopic parasite called Giardia lamblia. This is a common parasite causing gastrointestinal illness in the United States. Giardiasis can be a problem in areas where sanitation is poor, or when unfiltered water supplies are contaminated with the organism.

How is Giardiasis Spread?

A Giardia infection can be acquired when you ingest food or water which has been contaminated with the parasite. The parasite multiplies in the small intestine and is passed out with a bowel movement. Any food or drink which has become contaminated with an infected stool can transmit the parasite. The infection can also be spread person-to-person when hands, which are contaminated with an infected person's stool, are brought in contact with the mouth. Swallowing as few as ten parasites can cause the infection. Person-to-person transmission is the main way that giardiasis is spread, such as in day-care centers and institutions, where personal hygiene may be poor due to age (infancy, elderly) or disability. Giardiasis can also be spread in this manner in a household setting.

Are Animals Involved in the Spread of Giardiasis?

Giardia parasites have been found in the stools of many animals, including rodents, dogs, cats, cattle, and wild animals. Animals living near water supplies, such as beavers and muskrats, have been found to be infected with Giardia. The extent of direct animal-to-human transmission of Giardia is minimal; there is greater evidence of indirect transmission such as through contamination of water supplies.

What are the Symptoms of Giardiasis?

Symptoms of Giardiasis usually appear 7 to 10 days (and sometimes as long as 4 weeks) after ingesting the parasite. The most common symptoms are diarrhea, foul, greasy stools, abdominal cramps, bloating, increased gas, weakness and weight loss.

Do all People Who are Infected With Giardia Get Sick?

No. Some people who are infected with the parasite may only have minor symptoms and some people may not have any symptoms at all. However, these people can still pass Giardia parasites in their stool and become a source of infection for others.

How is Giardiasis Diagnosed?

Giardiasis is usually diagnosed through a laboratory examination of a stool sample. Your physician will forward the stool sample to a laboratory which will use a microscope to look for the parasite. Several stool samples may need to be examined to detect the parasite. The disease can also be diagnosed through a sample of fluid or a biopsy from the small intestine.

What is the Treatment for Giardiasis?

There are several medications which are effective in treating the infection. They are only available by prescription from your physician. Other treatments for diarrhea, such as increased fluid intake, may also be recommended by your physician.

How Can Giardiasis Be Prevented?

Giardiasis can be prevented by practicing good hygiene and using caution before drinking water from an unknown source.

Some general guidelines are:

1. Always thoroughly wash your hands with soap and water before meals, before preparing food, after having a bowel movement, after changing diapers, and after playing with you pets.

2. Do not drink untreated water from a surface water supply such as a pond, lake, or stream. Although the water may appear to be clean, it may contain Giardia parasites which cannot be seen without a microscope. If only untreated water is available, boil the water before drinking it.

3. If you are taking care of a person with Giardiasis, use extra precautions after contact with the person's stool (for example, after changing diapers). Promptly and carefully dispose of any material which has been contaminated with stool and always wash your hands after such contact.

4. If your source of drinking water is from a well or another surface water supply, do not allow humans or animals to defecate (have bowel movements) near the water. In addition, appropriate water filtration systems can be effective in removing Giardia parasites from contaminated water.


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