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What is it?

Giardiasis is an infection of the intestines caused by tiny parasites known as Giardia lamblia. Symptoms include diarrhoea, stomach cramps, bloating, severe flatulence, weight loss, and fatigue. Bowel movements may be loose, mucousy and greasy. One in every 25 people carry giardia without showing any symptoms. Symptoms appear within 5 to 25 days after contact; however, 7 to 10 days is the most common. Diarrhoea usually lasts several weeks, but occasionally becomes chronic. Giardiasis occurs worldwide and children are infected more often than adults.

How is it spread?

Giardiasis is found in the gut of infected humans and animals (beavers, muskrats, pets, livestock). It is usually spread through faecally contaminated water supplies or from touching human or animal faeces. People should be cautioned against drinking untreated surface water, such as water from rivers, streams, springs, and lakes. Swallowing water while swimming in any of these supplies also puts you at risk of acquiring a giardia infection. The parasite can also be spread from person to person through hand to mouth contact or unwashed hands touching items that will go into the mouth. It can spread quickly through a family when one member becomes infected or at a childcare centre where children have close contact with each other. Infected food handlers can also spread the parasite to food if proper hand washing is not practiced.

How is it prevented?

• Thorough hand washing is the best prevention. Make sure hands are washed properly after using the toilet, handling diapers, pets or livestock, and before handling foods.
• Avoid drinking water directly from rivers, creeks, lakes, and when you are uncertain whether the water has been properly treated, such as foreign travel.
• Unpasteurized milk products should be avoided.
• When travelling, camping or hiking, or if a “boil water” advisory has been issued, bring the water to a boil for 5 full minutes. This water should then be used for drinking, brushing teeth, rinsing dentures or contact lenses, making ice cubes, washing uncooked fruits and vegetables, and in recipes requiring water. Dishes should be washed with water that has been boiled.

For more information, please call Public Health at 519-376-9420 or 1-800-263-3456.

Source: Canadian Institute of Public Health Inspectors