The best way is to avoid food and water that is potentially contaminated. This is especially true if you travel to developing nations, where ice in a drink or a dinner salad may expose you to parasites. But the clearest mountain stream should also be suspect; it could be contaminated with Giardia. You cannot see most parasites; you won't be able to smell them or taste them in the water. If someone in your family has a parasitic infection, careful handwashing after going to the bathroom or handling soiled diapers can help prevent passing the parasite on to others. The infected person should avoid preparing food for others until their symptoms are gone.
No, only those that live in the digestive tract and whose eggs are passed through the stool. There are other tests specific for other parasites, such as pinworms, or blood parasites that cause malaria.
4. Are those parasitic worms I'm seeing in my stool sample?
Most of the common parasites are much too small to be seen with the naked eye. What you are probably noticing are undigested food fibers. The only way to be sure though is to look at the sample under the microscope. Parasites have characteristic external and internal structures that fibers do not have.
5. Are there other ways to test for intestinal parasites besides a stool exam?
Yes, blood antibody tests may be ordered to determine whether or not someone has been exposed to a parasite in the past. A positive result may indicate a past or a chronic infection but is not used to detect a current infection. Sometimes a biopsy of the small intestines is taken and the small amount of tissue is examined for parasitic infestation.
6. Once I've had a parasitic infection, can I be re-infected?
Yes, you can become re-infected if exposed again. This may happen if you have a family member who has an asymptomatic parasitic infection, such as giardiasis, and continues to shed the organisms and re-infects others. The infection can be transmitted until everyone is effectively treated.
7. Why shouldn't I take an over the counter anti-diarrhea medicine?
You should only take this on the advice of your doctor. Diarrhea is one of the methods your body uses to help rid itself of the infection. If you slow down or prevent this from happening by taking anti-diarrhea medication, you can prolong the amount of time that you are ill and may make your infection worse.
This article was last reviewed on August 30, 2011. | This article was last modified on March 4, 2015.
The review date indicates when the article was last reviewed from beginning to end to ensure that it reflects the most current science. A review may not require any modifications to the article, so the two dates may not always agree.
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