Definition Giardiasis is a gastrointestinal infection marked by diarrhoea. It is caused by the protozoan Giardia lamblia.
What is going on in the body? Giardiasis occurs all over the world. It is most common in areas where sanitation and hygiene are poor. Humans can acquire the disease by swallowing the organism in contaminated water. People can also acquire the disease when they handle faeces from infected persons. This is a problem in child-care centres, in particular
What are the signs and symptoms of the infection? Most people who have giardiasis do not have symptoms. When symptoms do occur, symptoms usually include:
watery diarrhoea
abdominal pain
flatulence
loss of appetite
In more severe cases, people can lose weight and children may stop growing. People with weakened defence systems or people with cystic fibrosis, an inherited disease affecting the lungs and other organs, can develop more serious complications from the infection.
What are the causes and risks of the infection?
close contact with the faeces of an infected person
drinking contaminated water
What can be done to prevent the infection? Good hygiene, especially when changing children's nappies, helps prevent spread of the infection. When drinking from natural sources, care should be taken to properly filter or boil the water. People who go to underdeveloped countries should not drink the water or eat uncooked fruits or vegetables.
How is the infection diagnosed? Giardia can be recovered from specimens of stool. The organisms can be seen with the aid of a microscope or detected using special enzymes.
What are the long-term effects of the infection? In severe cases, there may be weight loss or stunted growth in children.
What are the risks to others? Anyone who has the organism in the faeces can spread it to others, especially if they have poor hygiene practices.
What are the treatments for the infection? Metronidazole or fasigyn can be used to treat the condition. Other drug treatments for certain patients include furazolidine (for children) and paromomycin (for pregnant women).
What are the side effects of the treatments? People taking Metronidazole should avoid alcohol. Other side effects may include:
headache
anorexia or loss of appetite
nausea
vomiting
diarrhoea
abdominal cramps
What happens after treatment for the infection? Giardiasis usually responds readily to the medication and recovery is complete.
How is the infection monitored? A stool specimen will verify that giardiasis has been treated effectively.
Author: Danielle Zerr, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
