Risk factors

The giardia parasite is a very common intestinal parasite. Although anyone can pick up giardia parasites, some people are especially at risk:

• Children. Giardia infection is far more common in children than it is in adults. Children are more likely to come in contact with feces, especially if they wear diapers, are toilet training or spend time in a child care center. People who live or work with small children also are at higher risk of developing giardia infection.
• People without access to safe drinking water. Giardia infection is rampant wherever sanitation is inadequate or water isn't safe to drink. You're at risk if you travel to places where giardia infection is common, especially if you aren't careful about what you eat and drink. The risk is greatest in rural or wilderness areas.
• People who have anal sex. People who have anal sex or oral-anal sex without using a condom or other protection are at increased risk of giardia infection, as well as sexually transmitted infections.