Infectious Disease Epidemiology Program
Giardiasis is the most common infectious diarrheal illness reported in Maine. The disease is sometimes known as “beaver fever” because beavers (as well as dogs, cats, horses and cows) are a major reservoir for the parasite that causes infection. The parasite, Giardia intestinalis, lives in the intestines of infected humans and animals and contaminates water and soil when it is expelled through the feces. Hikers and campers that drink water in the wild that is not treated may become infected.