When you're camping, it's tempting to drink water straight from pristine-looking lakes and streams - but don't do it! Microscopic single-celled parasites can cause illnesses in humans if ingested. Here are two common waterborne diseases that could ruin your week:

• Cryptosporidiosis (crip-toh-spore-id-ee-oh-sis) is caused by Cryptosporidium (crip-toh-spore-id-ee-um). The symptoms include diarrhea, headache, nausea, and stomach cramps. It can show up 2 to 25 days after becoming infected, and the symptoms usually last for 1 to 2 weeks.
• Giardiasis (jee-ar-dye-a-sis), also known as "beaver fever," is caused by Giardia (jee-ar-dee-ah). It shares similar symptoms with cryptosporidiosis. Symptoms include diarrhea, gas, stomach cramps, weakness, and weight loss. Vomiting, chills, and headache may also occur. Symptoms first show up 6 to 16 days after becoming infected and can last for as long as 1 month.

How to prevent waterborne diseases:

• Use bottled water only, or boil water at least 1 minute before using it. Alternatively, you can purify water with iodine tablets or special water filters.
• Don't use water that hasn't been purified to brush your teeth or to wash dishes, fruits, or vegetables; don't use ice cubes made with water that hasn't been purified.
• Peel raw fruits and vegetables before you eat them.
• Wash your hands with bottled or purified water only, and do it carefully several times a day.
• Don't swallow water when you're swimming - even in a chlorinated swimming pool (chlorine doesn't kill all germs).
• One easy way to remember how to keep it safe: "Boil it, cook it, peel it, or leave it!"

If you think you have cryptosporidiosis or giardiasis, see your doctor right away. You may need to give stool samples to see if you have the parasite, and then get treated with prescription medications to get rid of it for good.

Some diseases picked up while traveling can also be a result of the food you eat. Traveler’s diarrhea, usually caused by E. coli bacteria, is one common infection encountered on trips abroad. It is characterized by stomach cramps, nausea, and several runny stools. It is more serious if these symptoms are accompanied by fever and pus or blood in the stool.

Dehydration is a complication of traveler’s diarrhea. Speak to your doctor or pharmacist about how the prevent dehydration with oral rehydration solutions. In addition to following the suggestions above, also avoid eating from street vendors and consuming unpasteurized dairy products or under-cooked foods. Speak to your doctor or pharmacist about other ways to prevent foodborne diseases or traveler’s diarrhea, such as oral vaccines.