Cases Of Recreational Water Illnesses On The Rise
Cryptosporidiosis or Crypto, a chlorine-resistant parasite, is likely to pose an even bigger
challenge in the future
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More recreational water illnesses (RWI) outbreaks were reported in 2007 than ever before, and the numbers
could increase in the coming years, according to the Centers for Disease Control and Prevention (CDC).
RWIs are illnesses that are spread by swallowing, breathing, or having contact with germs in the water of
swimming pools, spas, lakes, rivers, or oceans. To highlight the importance of healthy swimming habits, the
CDC has designated May 19–25, 2008, the week before Memorial Day, as National Recreational Water Illness
“The leading cause of RWI outbreaks is Cryptosporidium or Crypto, a chlorine-resistant parasite, primarily
associated with treated swimming places, such as pools and water parks,” explained Michele Hlavsa, an
epidemiologist at the CDC. “This RWI has been a public health issue in the past and will likely pose an even
bigger challenge in the future.”
During 2004-2007, the number of Crypto cases tripled. At the same time, the number of Crypto outbreaks
linked to swimming pools more than doubled. Because Crypto is chlorine resistant, even a well-maintained pool
can transmit this parasite.
“People need to practice healthy swimming habits, such as not swimming when they have diarrhea, not
swallowing the water, taking a shower before swimming, washing their hands after using the toilet or changing
diapers, and washing their children thoroughly -- especially their bottoms -- with soap and water before
swimming. To prevent outbreaks, we encourage pool operators to add supplemental disinfection to conventional
chlorination and filtration methods,” adds Hlavsa.
Symptoms generally begin two to 10 days (average seven days) after becoming infected with the parasite.
Crypto is characterized by watery diarrhea lasting one to three weeks. It can be spread by swallowing