Giardiasis is an infection affecting the bowels, mainly the small intestine. It is a parasitic infection caused by a parasite named Giardia lamblia. It often spreads from an infected person to others and after consumption of contaminated food and water. The causative parasite is commonly present across the world and in many parts of the U.S.

Causes of Giardiasis

Causes of Giardiasis

Giardiasis infection is caused by consumption of the parasite Giardia, mostly present in contaminated water. The parasite, after entering the body, travels the digestive tract, causing an infection in the small intestine and is excreted through feces. It is found in both humans and animals, which can further spread the infection to others. Giardiasis does not spread through blood.

How Does Giardiasis Spread or Transmission of Giardiasis?

While, the main cause of giardiasis is the entry of the parasite into the digestive tract of the person, there are several factors that cause exposure to and spread of giardiasis.

Common modes through which giardiasis spreads include:

  • Consuming food, water, ice or beverages made from water sources, which are infected with the parasite can cause Giardiasis. Using water from unhygienic sources and inadequately treated water can also cause Giardiasis.
  • Giardisasis can also be caused due to contamination of hands and ingesting the parasite from exposure to surfaces like tables, door handles, improper hand washing or diaper changing after toilet use, improper handling of feces, etc.
  • Consuming water from swimming pools, during recreational use of waters in water parks, lakes or rivers, which may be infected with Giardia parasite.
  • Consumption of uncooked or improperly cooked food, particularly vegetables that may be grown in soil contaminated with the parasite.
  • Coming in contact with persons suffering from giardiasis or travelling to areas known to have giardiasis infection spread.

Children can easily contract giardiasis, especially those exposed to child care centers in the diaper changing age and people coming in contact with them. Pregnant women too can contract giardiasis and the risk of dehydration from diarrhea is also high. International travelers and hikers who do not consume safe drinking water or do not practice proper hand washing techniques are at increased risk of giardiasis.

Symptoms of Giardiasis

Symptoms of giardiasis may begin 1 to 3 weeks after the exposure to the parasite Giardia.

The most common presenting symptoms of giardiasis is disturbance in the normal bowel movements. Loose motions or diarrhea, abdominal cramping pain, passing of painful motions and greasy stools is common. It may also be accompanied by few other symptoms like abdominal bloating, flatulence or excessive gas, nausea, vomiting and loss of appetite. Some people may feel general uneasiness, fatigue, headache and may even experience weight loss.

Anyone having possible giardiasis infection should receive proper medical treatment. If there are profuse watery stools, chances of dehydration are high, if complaints are associated with passage of mucus or blood in stools or if fever is present, immediate medical advice should be sought.

Diagnosis of Giardiasis

If the physician suspects giardiasis, stools samples are ordered for laboratory testing. It may not be assessed at once, so many stool samples may have to be submitted to detect the presence of Giardia parasite.

If required the physician may perform a test called enteroscopy. In this a small tube is inserted through the mouth, which reaches the small intestine and allows viewing of the area. A sample of a tissue is also taken from that area to detect the presence of the parasite and study its nature.

Treatment of Giardiasis

While giardiasis, mostly clears off on its own, medicines that fight the infection are prescribed to treat the infection. The prescribed course of anti-biotics needs to be taken to ensure complete freedom form giardiasis infection.

Management of acute giardiasis with diarrhea includes stopping solid diet, intake of water and electrolyte based fluids, fruit juices and plain soups. Soft bland food and regular diet can be slowly started once loose motions stop and normal stool begin to be formed. Avoiding food containing caffeine, milk and milk products can help.

Prevention of Giardiasis

Proper personal and community hygiene plays an important role in prevention of giardiasis. Washing hands regularly after using the toilets or diaper change, before and after handling food is necessary. Avoid sharing of personal items. Those involved in sexual practices need to understand that unprotected anal sex, improper handling of used condoms, licking and kissing can cause spread of infection and must be avoided.

Maintaining proper sanitation to avoid contamination of drinking water, cleaning and proper maintenance of swimming pools and water parks is a must. Drinking safe water and carrying boiled water when going out can help.

Travelers need to take extra care and using bottled water for drinking, brushing and rinsing mouth may be advised. Precautions regarding consumption of raw food, outside food and eating at unhygienic places need to be taken.

Carriers are those people who may not show any symptoms but pass the parasite in the stools possibly, remains of a previous giardiasis infection. Such carriers also need treatment to control the spread of giardiasis.

Written, Edited or Reviewed By:


Last Modified On: May 3, 2016

Pain Assist Inc.

Pramod Kerkar
  Note: Information provided is not a substitute for physician, hospital or any form of medical care. Examination and Investigation is necessary for correct diagnosis.

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