What is crypto?
Crypto is a parasite that causes diarrhea (inflammation of the stomach and intestines). The symptoms include diarrhea, stomach pain, fever, nausea, vomiting, weight loss and dehydration. Although symptoms typically start about two to 10 days after exposure, some people may show no symptoms. When the crypto “germ” is released in a bowel movement, the parasite is protected by a shell (oocyst) that makes it resistant to chlorine disinfectants. It would take more than eight hours to inactivate crypto if the chlorine was 20 parts per million (ppm) and much longer at normal pool chlorine levels. One accidental fecal release from an infected person can contain one billion germs. Therefore, if an infected person has a fecal release in a 100,000-gallon pool, each fluid ounce of pool water may contain 78 germs (52 germs in 20 mL) after the water is mixed. It takes as few as 10 germs to infect a person. Although current filtration is not particularly effective at removing these germs (which are a
