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Topics > Healthy Outlook > Follow Clean Practices to Prevent Waterborne Diseases

Follow Clean Practices to Prevent Waterborne Diseases

Published by Contra Costa Times

Posted on Wed., July 02, 2008
By Sherman Quinlan

When most people go swimming, they probably aren't thinking about becoming sick. But for all our sakes, maybe we should, because "crypto" might be swimming with us.

About 15 years ago, environmental health specialists began to see serious effects of a parasitic pathogen, cryptosporidium, that is resistant to chlorine and invisible to the naked eye. That made pool sanitation a whole lot more complicated.

The Federal Centers for Disease Control and Prevention (CDC) has documented that 62 percent of all recreational water illness in the United States now comes from "crypto."

Cryptosporidiosis causes a serious diarrhea that sickened hundreds of thousands during outbreaks in Milwaukee in 1993 and in several Rocky Mountain states last year. Despite not being identified until1976, it is one of the most common waterborne diseases and is found worldwide.

Symptoms appear from two to 10 days after infection and last for up to two weeks or so. As well as diarrhea, there is often stomach cramps, vomitting and fever.

In immunocompromised individuals, such as AIDS and some cancer patients, the infection can cause permanent, life-threatening infections.

For most healthy individuals, the best treatment is staying hydrated and waiting for the bug to pass. If necessary, prescription medicine is available.

Some individuals have no symptoms even if they are infected. They can pass it on to others without knowing. Even after symptoms subside, an individual is still infected for some weeks.

Like the better-known Escherichia, or E coli, "crypto" enters recreational waters such as pools, lakes and streams through the waste of infected animals and humans.

That is why there is the pool water illness prevention rule: "Don't get pool water in your mouth and never swallow it." This will go a long way toward preventing this illness.

Other ways to stop "crypto" outbreaks include showering before swimming, washing hands after using the bathroom or changing diapers, taking children on frequent bathroom or diaper change breaks and changing diapers in the bathroom, not at poolside. "Crypto" can be removed from drinking water by boiling.

The Environmental Health Division of Contra Costa Health Services Department is responsible for inspecting approximately 1,600 public pools and spas in Contra Costa County. That includes health clubs, municipal facilities, apartment and condo complexes, swim schools and swim clubs. We look for unsanitary, unsafe conditions and get owners and operators to take corrective action.

One of the topics covered in these seminars is "crypto" and how to get rid of it. This generally requires special filtration and ultraviolet radiation treatment of the water as it circulates.

This relatively new equipment is not mandatory yet, so all we can do is educate people on the health benefits of adding it. We encourage residential pool owners to do the same.

Unfortunately, there is no practical way to test for "crypto" in your pool. We have posted suggestions for preventing recreational water illness at and then clicking on Environmental Health.

Another online resource is, the Web site of the National Swimming Pool Foundation, which recently published an update on best practices when you suspect or find fecal material in your pool. Another is the CDC site at swimming.

Quinlan is director of the Environmental Health Division of Contra Costa Health Services.

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