 |
 |
Home |  |
Overview | |
The Disease | First Aid and Tips | About Us | |
Bibliography | |
Inside The Web |
||
|
The Disease |
||
Giardiasis Giardiasis , infection of the small intestine caused by the parasitic protozoan Giardia lamblia. The disease is contracted most commonly through poor personal hygiene or contact with an infected person, including the changing of soiled diapers or sexual contact. It also results from drinking untreated water or eating contaminated food. Giardiasis symptoms may include mild to severe diarrhea, nausea, abdominal cramps, poor appetite, and fatigue. Giardiasis occurs throughout the world. People at high risk for the disease include groups of children under the age of five in day care settings, individuals living in long-term care facilities, homosexual men and women, and people who drink untreated water from creeks and rivers. It is more common in tropical regions and impoverished areas that lack water treatment systems. During its life cycle Giardia lamblia appears in two forms: as a free-swimming trophozoite propelled by flagella and as an egg-shaped, inactive cyst surrounded by a thick, protective wall. Giardia are spread from one human or other mammal to another in the cyst form. After Giardia cysts are swallowed by a new host, stomach acids and digestive enzymes dissolve the cysts to release trophozoites. The free-swimming trophozoites, or active protozoans, attach to the wall of the small intestine and reproduce. Exposure to high concentrations of bile in the intestinal environment stimulates trophozoites to change into the cyst form. The thick wall of the cyst protects the trophozoite when it is excreted with fecal material and, if kept moist, enables it to survive for two to three months outside the body. About two-thirds of people infected with Giardialamblia show no symptoms after infection. In others, the onset of symptoms takes seven to ten days. This delay of symptoms distinguishes giardiasis from food poisoning in which similar symptoms, along with fever, develop within hours of a meal. Giardiasis is diagnosed by examining fecal material in a laboratory for the presence of cysts. If necessary, a biopsy may be performed in which a sample of intestinal tissue is removed and examined under a microscope for the presence of trophozoites. Previous to go back to the diseases
|
