Disease Report Investigation Process
What is giardiasis?
Giardiasis is an infection caused by a parasite called
Giardia lamblia. Giardiasis has a worldwide
distribution and is a common cause of diarrhea in the United States.
Who gets giardiasis?
Anyone can get giardiasis, but children are infected
more frequently than adults. Persons who drink
untreated water also are at greater risk of becoming
infected with Giardia.
Where are Giardia organisms found?
Humans are the main host of Giardia, but Giardia cysts can also be found in:
domestic and wild animals
Giardia cysts are also found in lakes and streams contaminated with feces
from an infected animal or human.
Giardia may also
be present in areas of poor sanitation, and child care
centers with children who are not toilet trained.
How is giardiasis spread?
Giardia is passed in the feces of an infected person
or animal and may contaminate food or water.
disease can spread from person-to-person in child care
centers, especially those that care for children who
are not toilet trained.
Backpackers, campers and
hunters may get giardiasis by drinking directly from
lakes or streams, even though the water may appear
What are the symptoms of giardiasis?
The most common symptoms of giardiasis include:
Mild or severe diarrhea with loose and pale greasy
Fever is rare
Some people may not become
ill, but may still transmit their infection.
children often have no symptoms. (Children in child care centers may often be infected, but do not
need treatment unless they get diarrhea.)
How soon do symptoms appear?
Diarrhea usually begins within seven to 10 days, but may
be as early as five days or as late as 25 days after
infection with Giardia.
How long can an infected person spread
The disease can be spread as long as the infected
person excretes cysts. Treatment may shorten length
What is the treatment for giardiasis?
Anti-parasitic medication is often given to treat
giardiasis. Some people recover without treatment.
Does everyone infected with giardia need to
Should an infected person be excluded from
work or school?
Children with diarrhea should not attend a child care
facility. They may return when diarrhea stops.
Food handlers and child care workers who have giardiasis must test negative for Giardia lamblia cysts before returning to work.
What can be done to stop the spread of
Some general guidelines are:
Carefully wash hands after using the toilet or
Dispose of sewage properly so water sources will
not be infected.
Do not drink water that has not been properly
When camping, boil your water before
Where can I get more information?
Contact your doctor or the Southern Nevada Health District, Office of Epidemiology at (702) 759-1300.