Giardiasis

Giardia (say gee-ar-dee-ah) is the name of a microscopic parasite that can live in the human bowel. The sickness that this parasite causes is called giardiasis (say gee-ar-dye-a-sis). Some symptoms of giardiasis are diarrhea, belching, gas and cramps. Although these problems are very unpleasant, the illness isn't usually dangerous.

Giardiasis is easy to catch if you drink untreated spring water or stream water. Many animals carry giardia in their feces and may introduce this parasite into rivers, streams and springs in rural areas. Infected stream water may look clean and safe when it really isn't. City water may also be infected if sewer lines flood or leak. If you travel overseas, you may get giardiasis by drinking water (even tap water) that hasn't been boiled or treated.

Some people who get giardiasis don't become ill, but they may spread the parasite to other people. Giardiasis may be spread in day care centers if workers aren't careful to wash their hands each time after changing diapers.

You should be very careful about the water you drink. If you go camping, take bottled water or boil water before you use it. Wash your hands carefully with soap and water several times a day. If you are traveling, don't brush your teeth or wash dishes with water that hasn't been boiled. Peel raw fruits and vegetables before you eat them, and don't eat undercooked food. If someone in your family gets giardiasis, it's likely that this problem will spread to everyone in your home--especially to the children.

Your doctor can usually diagnose giardiasis by looking at stool samples under a microscope, although several samples may have to be checked before the diagnosis can be made. Sometimes other tests may be necessary.

Giardiasis is usually treated with a medicine called metronidazole (brand name: Flagyl). It's usually taken 3 times a day for 5 to 10 days. Side effects may include a metallic taste in the mouth or nausea. If you take Flagyl, you should not drink any alcohol. This medicine shouldn't be taken in the early stages of pregnancy.

Young children (under 5 years old) may be treated with furazolidone (brand name: Furoxone). This medicine has fewer side effects and comes in a liquid form, but it shouldn't be given to babies younger than 1 month old.

It's usually best if a whole family is treated at the same time, because giardiasis is so easily spread. In most cases, your doctor will want to check a stool sample after the treatment, to be sure the medicine worked. Sometimes you may need to take medicine for a longer time, or your doctor may want you to take another medicine for a complete cure.