[pct-l] Afraid of Crypto? Stay out of the pool...

[brick@fastpack.com (Brick Robbins)]

http://www.signonsandiego.com/news/uniontrib/sun/news/news_0n17pools.html

Parasite in pools causing more swimmers to become ill, studies find

By Seth Borenstein
KNIGHT RIDDER NEWS SERVICE

November 17, 2002

DENVER =96 Swimming pools are giving people diarrhea and putting more
Americans at risk of contracting the illness, according to two
yet-to-be-released federal studies.

The number of U.S. swimming-related outbreaks of illness caused by the
parasite Cryptosporidium increased tenfold from 1990 to 2000, the Centers
for Disease Control and Prevention will announce Thursday.

Americans who swim in pools are 10.6 times more likely to contract the
parasite than those who do not, according to preliminary results from
another CDC study. While neither study has been published, epidemiologist
Michael Beach let scientists see the data Wednesday at the American Society
of Tropical Medicine and Hygiene convention in Denver.

During the past decade, the microscopic Crypto parasite has become
resistant to chlorine, which is the main pool-cleansing agent, Beach said.
The parasite, which lives in human and animal intestines, causes a disease
also called Crypto, which brings on diarrhea, can include fever and lasts
about two weeks. For people with weakened immune systems, it can lead to
more serious disease.

Crypto is one of the major waterborne diseases in the United States, the
CDC says. And in the past two years more than 80 percent of the outbreaks
from swimming pools have been due to the chlorine- resistant strain, Beach
said.

The parasite is spread through feces. The biggest culprits behind its
presence in swimming pools are children who are not yet potty- trained.

"A single fecal accident in one of these major water parks is plenty to
contaminate millions of gallons of water," Beach said. "You only have to
swallow a mouthful of water or two to get contaminated."

The latest statistics on the disease, for 1999 and 2000, show "a very sharp
increase over the past two years" in the number of Crypto outbreaks from
recreational swimming, Beach said.

Because 18 percent of the people who are ill with diarrhea continue to
swim, the outbreak often resurfaces soon after swimming pools are drained
and refilled, Beach said.

"It's very hard to stop an outbreak like this," he said. "The people won't
stop swimming."

Preliminary results of a risk analysis of swimming show that people who use
kiddie pools have a 10.7 times higher risk of contracting Crypto than those
who do not swim. The risk is 10.6 times higher for swimmers in regular
pools, 2.4 times higher for ocean swimmers and 1.7 times higher for lake
swimmers, Beach said.

Better filtration and disinfectant technology geared for swimming pools is
needed, Beach said. Until then, the key is public education =96 telling
people not to swim if they have diarrhea and trying to keep toddlers from
soiling pools.
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Brick Robbins                       mailto:brick@fastpack.com