Font Size
A
A
A
1
...

Giardiasis

Giardiasis Overview

Giardiasis is an infection of the small bowel by a single-celled organism called Giardia lamblia. People become infected with the Giardia parasite after swallowing Giardia cysts often found in water contaminated by raw sewage or animal waste.

  • Giardiasis can be found among 2% to 5% of people in industrialized nations such as the United States. In developing countries, up to 33% of the population may have had giardiasis. In the US, it is the most common intestinal parasitic disease.
  • Travelers to foreign countries may develop diarrhea often caused by Giardia.

Giardiasis Causes

Giardia cysts are transmitted to humans in various ways.

  • Contaminated water supplies: Giardia is one of the most common causes of water-borne diarrhea outbreaks. Sources of contaminated water include public facilities that improperly filter and treat water, water in developing countries, or rivers and lakes used by hikers. Overseas travelers and hikers are at a high risk for infection.
  • Contaminated food: Food that may have been washed in contaminated water, exposed to manure, or prepared by an infected person can transmit the disease.
  • Person-to-person contact: Infection may be caused by poor hygiene and most commonly occurs in daycare centers, nursing homes, and during oral-anal sexual contact. Up to 50% of children infected with Giardia in daycare centers, and up to 20% of infected sexually active homosexual males, pass cysts in their stool. Family members, daycare workers, and others in contact with infected stool may then themselves become infected.

Medically Reviewed by a Doctor on 11/16/2012
Medical Author:

Must Read Articles Related to Giardiasis

Dehydration in Children
Dehydration in Children Dehydration in children can result from not drinking enough liquids, vomiting, diarrhea, or combination of these conditions. Causes of dehydration in children i...learn more >>
Gastroenteritis (Stomach Flu)
Gastroenteritis Gastroenteritis (stomach flu) is most commonly caused by viruses and bacteria like rotavirus, adenovirus, parvovirus, and astrovirus. Bacteria causing gastroent...learn more >>
Traveler's Diarrhea
Traveler's Diarrhea Causes of traveler's diarrhea include bacteria, viruses, and protazoa. Traveler's diarrhea is contagious with symptoms of loose or watery stools, abdominal cram...learn more >>




Read What Your Physician is Reading on Medscape

Giardiasis »

Giardia lamblia was originally identified by von Leeuwenhoek in the 1600s and was first recognized in human stool byVilem Dusan Lambl (1824-1895) in 1859and by Alfred Giard (1846-1908) after whom it is named.

Read More on Medscape Reference »


Medical Dictionary