What Is Giardiasis?
Giardiasis is an illness that affects the digestive tract (stomach and intestines). It's one of the top causes of diarrhea in the United States.
What Causes Giardiasis?
Giardiasis (jee-are-DYE-uh-sis) is caused by the microscopic Giardia parasite. The parasite attaches itself to the lining of the small intestines in humans, where it causes diarrhea and interferes with the body's absorption of fats and carbohydrates from digested foods.
Is Giardiasis Contagious?
Giardiasis is very contagious, and can spread easily among families. In childcare centers or any facility caring for a group of people, giardiasis can easily pass from person to person.
How Does Giardiasis Spread?
Giardiasis spreads through water contaminated with the stool (poop) of someone who's infected. Animals (mainly dogs and beavers) who have giardiasis also can pass the parasite in their stool. The stool can then contaminate public water supplies, community swimming pools, and water sources like lakes and streams.
Uncooked foods that have been rinsed in contaminated water and surfaces contaminated by stool (for instances, diaper pails and toilet handles) also can spread the infection.
The Giardia parasite can survive the normal amounts of chlorine used to purify community water supplies, and can live for more than 2 months in cold water. As few as 10 of the microscopic parasites in a glass of water can cause a severe case of giardiasis in a person who drinks it.
Who Gets Giardiasis?
In developing countries, giardiasis is a major cause of epidemic childhood diarrhea. But even people in developed countries can get the infection.
Young kids are more likely to have giardiasis than adults. So some experts think that our bodies gradually develop some form of immunity to the parasite as we get older. But it isn't unusual for an entire family be infected, with some family members having diarrhea, some just crampy abdominal pains, and others with no symptoms.
What Are the Signs and Symptoms of Giardiasis?
Many people with giardiasis have no signs or symptoms of illness, even though the parasite is living in their intestines.
When the parasite does cause symptoms, the illness usually begins with severe watery diarrhea. Giardiasis affects the body's ability to absorb fats from the diet, so the diarrhea contains unabsorbed fats. That means that the diarrhea floats, is shiny, and smells very bad.
Other symptoms include:
- abdominal cramps
- large amounts of intestinal gas
- an enlarged belly from the gas
- loss of appetite
- nausea and vomiting
- sometimes a low-grade fever
These symptoms may last for 5 to 7 days or longer. If they last longer, a child may lose weight or show other signs of poor nutrition.
Sometimes, after acute (or short-term) symptoms of giardiasis pass, the disease begins a chronic (or more lasting) phase. Symptoms of chronic giardiasis include:
- periods of intestinal gas
- abdominal pain in the area above the navel (belly button)
- poorly formed, "mushy" bowel movements (poop)