Parasites in the Pool


A particular parasite, called Cryptosporidium, is showing up in pools, lakes and fountains, causing a diarrheal disease known as cryptosporidiosis, or “crypto” for short. A new report from the Centers for Disease Control and Prevention found 134 disease outbreaks associated with recreational water in 2007 to 2008, when the most recent data is available. That is a 72 percent increase over the previous two-year period. Of all 105 confirmed disease outbreaks in pools and fountains, Cryptosporidium was responsible for 57 percent of them, causing over 12,000 illnesses.

The parasite can cause diarrhea in all age groups, but immune-compromised individuals, the very young, and very old are particularly susceptible to more serious illness upon infection. Symptoms of crypto include abdominal cramping, frequent watery diarrhea, nausea, feeling ill, and even malnutrition and weight loss in severe cases. In most people, however, a crypto infection is not dangerous, but it’s uncomfortable.

Cryptosporidiosis spreads by contact with contaminated water, and as the bacterium is tolerant of chlorine, it may not be possible to avoid contact. While it is not common for a pool to be contaminated with this parasite, Cryptosporidium contamination is increasing. Proper sanitation and hygiene are important for prevention of this illness. People, and especially infants, with diarrhea should not swim in pools until their diarrhea subsides. Infants should wear protective diapers when swimming. Try not to swallow water and be sure to wash hands after swimming to stay on the safe side.