Alternative Names: Giardia; Traveler’s diarrhea – giardiasis
Giardiasis is an intestinal infection caused by a protozoan and is spread by contaminated water or contact with an infected person.
Giardiasis or beaver fever in humans is a diarrheal infection of the small intestine by a single-celled organism called Giardia lamblia. Giardiasis occurs worldwide with a prevalence of 20–30% in developing countries. In the USA, 20,000 cases are reported to the CDC annually, but the true annual incidence is estimated at 2 million people. Giardia has a wide range of mammalian hosts besides humans, thus making it very difficult to eradicate. For people with compromised immune systems, such as elderly or AIDS patients, giardiasis can be deadly
The parasite was first identified in 1681 by Anton von Leeuwenhoek, the ‘father of microbiology’. In 1859 a Bohemian doctor, Vilem Lambl, found giardia in human faeces and from then on it was thought to be a harmless occupant of the intestines. It wasn’t until the 1970s that giardia was given its true status as one of the world’s most common causes of diarrhoeal illness.
Giardia is a type of single-celled organism called a protozoon. It first came to light in the UK as an important cause of diarrhoea among those returning from abroad. It’s a major cause of childhood diarrhoea in developing countries and is also common in Eastern Europe and across the US. However, giardia can be found around the globe and is the most common gut parasite in the
One reason it can be difficult to control the spread of giardia is that as many as 15 per cent of those carrying the organism have no symptoms. They become a source of the parasite, contaminating the environment without realising it.
However, most people develop a variety of gastrointestinal symptoms like:
•Gas or bloating
•Loss of appetite
•Nausea and stomach cramps
•Swollen or distended abdomen
These symptoms can persist for several weeks and, without treatment, can lead to dehydration and weight loss. In developing countries, where people (especially children) may already be malnourished, an infection can prove fatal.
People or animals carrying giardia in their intestines pass it out in their faeces. The parasite is then spread through poor hygiene or contaminated soil, food or water (see box below). With a tough outer shell, the parasite can survive for long periods outside a host body. A person only needs to pic1982k up a few giardia cysts for infection to develop.
•Putting something in your mouth that has been contaminated by faeces from an infected person or animal.
•Drinking contaminated water. Public water supplies in the UK are considered to be at low risk as giardia is killed by adequate chlorination.
•Swallowing water during recreation that is contaminated with sewage – for example, in swimming pools, jacuzzis, lakes, rivers or ponds.
•Eating contaminated food. One report found cases linked to the consumption of lettuce.
•Coming in contact with surfaces or objects that have been contaminated by an infected person.
Giardiasis outbreaks can occur in communities in both developed and developing countries where water supplies become contaminated with raw sewage.
It can be contracted by drinking water from lakes or streams where water-dwelling animals such as beavers and muskrats, or domestic animals such as sheep, have caused contamination. It is also spread by direct person-to-person contact, which has caused outbreaks in institutions such as day care centers.
Travelers are at risk for giardiasis throughout the world. Campers and hikers are at risk if they drink untreated water from streams and lakes. Other risk factors include:
•Exposure to a family member with giardiasis
•Institutional (day care or nursing home) exposure
•Unprotected anal sex
•Malabsorption (inadequate absorption of nutrients from the intestinal tract)
Giardiasis is diagnosed by checking stool samples for the parasite. It can be difficult to find, though, and it’s often necessary to send several samples for analysis.
Tests that may be done include:
•Stool antigen test to check for Giardia
•Stool ova and parasites exam
•String test (rarely performed)
This disease may also affect the results of the following tests:
•Small bowel tissue biopsy
•Smear of duodenal aspirated fluid
Some people recover completely from giardiasis without specific treatment. For other, the infection persists for weeks or even months. Treatment with antibiotics will shorten the course of the illness and reduce the risk of spread to others. Antibiotic therapy is particularly important for those, such as young children, who are at greater risk.
Steps should also be taken to treat or prevent dehydration, and people with giardiasis should drink plenty of fluids. Severe dehydration may need hospital treatment, with an intravenous drip.
Cure rates are generally greater than 80%. Drug resistance may be a factor in treatment failures, sometimes requiring a change in antibiotic therapy.
In pregnant women, treatment should wait until after delivery, because some drugs used to treat the infection can be harmful to the unborn baby.
It is common for the infection to go away on its own. However, persistent infections have been reported and need further antibiotic treatment. Some people who have had Giardia infections for a long time continue having symptoms even after the infection has gone.
Good hygiene should help to keep you safe from giardia. Always wash your hands after using the toilet or changing nappies, and before handling food. Don’t share towels.
Don’t swim, or let your children swim, in pools, rivers, lakes or the sea during an episode of diarrhoea, and for at least two weeks after treatment.
When abroad, make sure the water supply is safe, or drink only purified or bottled water. Also avoid ice in drinks, and fruit and salad vegetables washed in tap water.
Avoid exposure to faeces during sexual activity (homosexual men may be at increased risk of infection).
Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.