Water-Related Infections Hit New High
CDC sees rise in chlorine-resistant organisms, untreated wells
THURSDAY, Nov. 21, 2002 (HealthDayNews) -- The number of swimming-related infection outbreaks hit a record high in 1999-2000, with 59 episodes that caused almost 2,100 illnesses and at least four deaths, according to a new government report.
Another 39 outbreaks linked to drinking water sickened 2,068 Americans and killed two during the period. Officials attributed those infections largely to unsanitary private wells.
Some of the increase is due to greater surveillance and reporting of waterborne infections. But part of the rise is real, said Michael Beach, a CDC water safety expert. It's "a tip of the iceberg thing," said Beach. "We don't detect most" of the infections.
Deborah Levy, who heads the CDC's water surveillance program, said the monitoring system "is not very sensitive to accuracy" in collecting cases. "We're basically limited to what comes in on the report forms" from states, which voluntarily provide the information each year, she added.
Recreational outbreaks in 1999-2000 hit the highest level since officials began tracking them in 1978, Beach said. The bulk of the episodes -- usually defined as infections of at least two people from the same source -- involved diarrheal ailments, which rose from 18 in 1997-98 to 36 in 1999-2000.
The most common culprits for diarrheal illnesses were Cryptosporidium in treated water and E. coli bacteria in fresh water. Cryptosporidium, a parasite, has shown signs of resistance to conventional levels of chlorine used to treat swimming pools, Beach said. Viruses, chemicals and unidentified agents also caused outbreaks, leading to gastric symptoms as well as skin irritation and even inflammation of the brain and spinal fluid.
Beach said swimmers need to "think about who you are swimming next to." People shouldn't go in the water if they have diarrhea, and they should shower before swimming. Parents should change diapers away from pools and be sure to wash up well afterwards. And remember, he warned: "Swimming water is not drinking water."
Better pool maintenance is also key to reducing waterborne outbreaks, Beach said.
Of the 39 drinking water outbreaks in 1999-2000, 11 involved surface water, an increase of 11 percent from 1997. The 28 groundwater outbreaks marked an 87 percent spike from 1997, when 15 occurred. Six in 10 involved untreated groundwater.
Sherline Lee, another CDC water official, said that while outbreaks involving municipal water supplies remain relatively rare in this country -- thanks to the efforts of water safety authorities -- unregulated wells pose a bigger problem. Americans drill 30,000 new wells a year, many of which are private.
"We urge the public to actively think about what they drink," Lee said.
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