Compiled By: Julie A. Albrecht, Ph.D., Associate Professor

The Organism: Giardia lamblia is a flagellate protozoa (single cell animal). In the stable cyst stage, the organism can be shed in the feces of infected humans. The cyst cannot multiply outside of a living host.

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Sources of the organism:

• Intestinal tracts of infected animals and humans
• Water

Associated foods:

• Water
• Any food handled by an infected food handler

Organism Characteristics:

• Protozoa which can survive normal water chlorination.

The Disease: Giardiasis results from the consumption of the cyst stage of the Giardia lamblia protozoa.

Symptoms include:

• Diarrhea
• Flatulence
• Bloating

Onset time:

• 1-4 weeks

Infective Dose:

• Consuming 1 or more cysts may cause the symptoms of the illness to develop.

Duration of symptoms:

• Weeks

Control:

• Proper disposal of feces and wastewater treatment.
• Proper filtration before chlorination of the water supply.
• Cooking contaminated foods.
• Boiling suspect water.
• Use proper hand washing techniques and practice good personal hygiene procedures.