Giardia lamblia is commonly associated with which source?

• A. Dairy products
• B. Soil and water
• C. Leafy greens
• D. Meat

Answer: (B)

Giardia lamblia spreads mainly through ingestion of cysts that are shed in feces and can survive for long periods in the environment. The cysts are particularly hardy in water, so contaminated drinking water, ice, or water used to wash produce is a common way people become infected. Soil can also harbor these cysts when fecal contamination is present, leading to exposure through hands or foods grown in that soil. Because of this environmental reservoir, both soil and water are the sources most commonly linked to Giardia infections. Dairy products, meat, and leafy greens are not the usual vehicles for Giardia, even though greens can become contaminated if grown or washed with contaminated water.