(GEE-are-DYE-uh-sis)
Giardiasis (GEE-are-DYE-uh-sis) is a diarrheal illness caused by Giardia intestinalis (also known as Giardia lamblia ), a one-celled, microscopic parasite that lives in the intestine of people and animals. The parasite is passed in the stool of an infected person or animal. The parasite is protected by an outer shell that allows it to survive outside the body and in the environment for long periods of time. During the past two decades, Giardia has become recognized as one of the most common causes of waterborne disease (drinking and recreational) in humans in the United States. The parasite is found in every region of the United States and throughout the world.
Symptoms include diarrhea, loose or watery stool, stomach cramps, and upset stomach. These symptoms may lead to weight loss and dehydration. Some people have no symptoms. Symptoms generally begin 1-2 weeks after being infected. In otherwise healthy persons, symptoms may last 2-6 weeks. Occasionally, symptoms last longer.
Giardia lives in the intestine of infected humans or animals. Millions of germs can be released in a bowel movement from an infected human or animal. You can become infected after accidentally swallowing the parasite. Giardia may be found in soil, food, water, or surfaces that have been contaminated with the feces from infected humans or animals. Giardia is not spread by contact with blood. Giardia can be spread by:
Everyone. Persons at increased risk for giardiasis include:
Several community-wide outbreaks of giardiasis have been linked to drinking municipal water or recreational water contaminated with Giardia .
Yes, Giardia can be very contagious. If you have Giardia , follow these guidelines to avoid spreading it to others:
Your health care provider will likely ask you to submit stool samples to see if you have the parasite. Because Giardia can be difficult to diagnose, he or she may ask you to submit several stool specimens over several days.
Several prescription drugs are available to treat Giardia . Consult with your health care provider. Although Giardia can infect all people, young children and pregnant women may be more susceptible to the dehydration resulting from diarrhea. They should drink plenty of fluids while ill.
If you answer yes to the following questions, consider having your well water tested:
Tests specifically for Giardia are expensive, difficult, and usually require hundreds of gallons of water to be pumped through a filter. If you answered yes to the above questions, consider testing your well for fecal coliforms or E. coli instead of Giardia . Although fecal coliforms or E. coli tests do not specifically test for Giardia , testing will show if your well has fecal contamination. These tests are only useful if your well is not routinely disinfected with chlorine since chlorine kills fecal coliforms and E. coli . If the tests are positive, the water may also be contaminated with Giardia , as well as other harmful bacteria and viruses. Look in your local telephone directory for a laboratory or cooperative extension that offers water testing. If the fecal coliform test comes back positive, indicating that your well is fecally contaminated, contact your local water authority for instructions on how to disinfect your well.
In general, the answer by the American Academy of Pediatrics is that treatment is not necessary. However, there are a few exceptions. If your child does not have diarrhea, but is having nausea, or is fatigued, losing weight, or has a poor appetite, you and your health care provider may wish to consider treatment. If your child attends a day care center where an outbreak is continuing to occur despite efforts to control it, screening and treatment of children without obvious symptoms may be a good idea. The same is true if several family members are ill, or if a family member is pregnant and therefore not able to take the most effective anti- Giardia medications.
Source:
Centers for Disease Control and Prevention, May 2001
Last reviewed May 2001 by EBSCO Publishing Editorial Staff
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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