-C. Paula de los Angeles
I've always been hesitant to swim in public swimming pools, and the recent reports of the sharp increase in recent years of reports of gastrointestinal illness from use of public pools and water parks has only confirmed these fears.
If one thinks that chlorine can kill any parasite and stop the spread of infectious disease, one is wrong. Cryptosporidium has an egglike shell that allows it stay alive in chlorinated water for up to 10 days. Statistics have shown an increase from 7 outbreaks affecting 567 people in 2004 to 31 outbreaks affecting 3726 people in 2007. However, it is unclear whether the increase is a result of an increase in incidence or reporting.
Epidemiologist Michele C. Hlavsa of the CDC has noted that the development of a treatment for the diarrheal disease, cryptosporidiosis, in 2002 could have led to an increase in detection and reporting. Symptoms include diarrhea and dehydration.
To swim or not to swim? Public health officials encourage people to still swim, but to "be smart about it". To them, this means not allowing children to swim when they have diarrhea. Do not swim in cloudy water. Do not swim in pools with slick tiles or without humming filtration machines. Don't use the pool as a toilet.
With that in mind, I'll think twice before I jumped into a pool this summer.
News link here: http://www.nytimes.com/2009/06/16/health/16water.html?ref=science