In 2007 state and local health departments nationwide investigated record numbers of recreational water-illness outbreaks. Driven by diarrheal illness caused by chlorine-resistant protozoa of the genus Cryptosporidium, this upsurge is primarily associated with venues such as public pools and water parks and can affect large numbers of people. From 1995 through 2004, Cryptosporidium caused seven such outbreaks annually; in 2006, 18 outbreaks were reported to the Centers for Disease Control and Prevention (CDC), which has received reports of at least 18 outbreaks for 2007; that number will likely rise.

Nurses can help by educating the public, especially parents of young children. The CDC offers a teaching guide: the Six "PLEAs" for Healthy Swimming. Here they are, taken directly from the CDC Web site:

* Please don't swim when you have diarrhea. You can spread germs in the water and make other people sick. This is especially important for kids in diapers.

* Please don't swallow the pool water. In fact, avoid getting water in your mouth.

* Please practice good hygiene. Take a shower before swimming and wash your hands after using the toilet or changing diapers. Germs on your body end up in the water.

* Please take your kids on bathroom breaks or check diapers often. Waiting to hear "I have to go" may mean that it's too late.

* Please change diapers in a bathroom or a diaper-changing area and not at poolside. Germs can spread to surfaces and objects in and around the pool and spread illness.

* Please wash your child thoroughly (especially the rear end) with soap and water before swimming. Everyone has invisible amounts of fecal matter on her or his bottom that will end up in the pool.

Find more educational materials, including posters, at http://www.cdc.gov/healthyswimming. For information on cryptosporidiosis, go to http://www.cdc.gov/ncidod/dpd/parasites/cryptosporidiosis/default.htm.