Cause: The parasite Giardia lamblia

How spread: Drinking contaminated water

Areas of risk: Common anywhere there is contamination of surface or domestic water. Commonly spread through day cares of underdeveloped countries. Outbreaks have occurred in cities where water is not properly treated.

Incubation period: One to four weeks

Symptoms: Diarrhea, bloating, excessive gas, severe stomach aches

Treatment: Usually goes away on it's own; Metronidazole may be prescribed

Mortality Rate: Death is very rare

Prevention: Use precaution when eating food or drinking water, especially when hiking or camping. Properly cook food. Drink bottled water when hiking or camping. If bottled water is not available boil or filter your water.