As summer approaches anyone with half a passion for the outdoors can't resist the allure of the crisp clean waters of northern Ontario. We are spoiled by having access to so much pristine wilderness, miles of meandering rivers and lakes which glitter and shine like crystals in the sun. But all that glitters is not golden. One must sometimes beware of what one cannot see.

Resting your paddle on the gunwales of the canoe, you dip your cup over the side and extract a cool, thirst-slaking refreshing cup of northern Ontario with which to moisten your esophagus. You give little credence to the fact that this lake while providing life to all the fish, birds and mammals living in it, also happens to be their toilet...Yeecchh!! But the water is so clear, so cold and so essential to life that you gulp it down healthfully.

Unbeknownst to you that cup of water was briefly home to a host of tiny organisms that escaped detection by your less than microscopic vision. Swimming among this aquatic zoo-in-a-cup may have been a tiny animal that just happens to be in search of an intestine in which it can have babies and live happily ever after.

We're talking about beaver fever. And it can make you sick! Real Sick!

Beaver fever or Giardiasis is caused by a tiny, one-celled animal (protozoan) named Giardia lamblia. It is the parasite that often comes home with people from foreign lands and causes abdominal pains, diarrhea and nausea for weeks not to mention the dehydration and flatulence that result as well. Once infected, symptoms take about a week to show up although the incubation period ranges from five to 25 days. Giardia spreads from unwashed hands to mouth, in contaminated water and on unwashed salad greens. The disease was commonly known as beaver fever as beavers and many other wild animals such as bears, raccoons and muskrats are known hosts for the parasite which is released in their droppings. It is now known that not only beavers carry Giardia but dogs, cats and parakeets do as well. Flies which have been stomping around in filth may pick up the microorganism and land on that snack you are enjoying so much at a summer family picnic.

The motile form of giardia propels itself with eight whip-like tails or flagella. However, it is the cyst form that is the secret to its success (and our misery). The cyst covers Giardia so securely that it can remain dormant for months. It can even withstand trips through the sewage treatment plant. Once the cyst enters the intestine disease symptoms occur in response to excessive population growth of the motile form of the parasite which is released from the cyst. The organism then attaches itself to the wall of the intestine. Fortunately, the disease is easily treated with a prescription antibiotic.

Using common sense will go a long way in avoiding Giardia. For starters, it is recommended that any water you drink while hiking or camping in the wild, no matter how clear it appears, should be treated. Water should be boiled for at least five minutes before drinking. Water for tea and coffee and even brushing your teeth must be boiled as well. Many high quality water filters are on the market now that will filter out organisms as small as Giardia. Although a little more expensive and time consuming, you can rest assured that the water you consume is free of disease causing organisms and free of chemicals as well.

Since your pet may carry Giardia, it is recommended that you always wash your hands after petting your animal. Allowing your animal to lick you near your mouth puts you at obvious risk for picking up a disease-causing agent. It is known that 65 infectious diseases can be transmitted from dogs to humans and 39 by cats.

Giardia can be transmitted from person to person therefore it is important to wash your hands after using the toilet or after changing a diaper, and before handling food. Day-care centres are prime sites for Giardia outbreaks. It is a must that children are made aware of the importance of washing their hands after using the toilet.