Giardiasis is a protozoan infection that is one of the most
prevalent causes of diarrhea. It has been recognized in
approximately 100 countries in various parts of the world.
Isolated cases and even epidemics of this illness have occurred
in the United States. Beavers are the main carriers of this
parasite, which is transmitted by water supplies contaminated
with the excrement of beavers. Cysts of these protozoa are
removed by sand filters, but also require chlorination. They are
also killed by heating to 122 degrees Fahrenheit (50 degrees
Celsius) or by chemicals that contain iodine. The usual symptoms
are diarrhea with watery, foul-smelling stools, abdominal
distension and pain, and loss of weight. In most cases symptoms
are mild to severe, lasting from a few days to a period of
weeks, though occasionally there are no symptoms at all. In many
persons both parasites and symptoms disappear without treatment.
Identifying the causative organism under the microscope makes
the diagnosis. Your physician will presc