Pool Parasites: Public Water Disease Outbreaks
There are 309,000 public swimming pools in the United States, and it's probably safe to say that a child has urinated in each and every one of them. Urine itself is non-toxic, so -- while off-putting -- taking a leak is not a imminent health danger. The biggest concern is that the waste product makes the pool more hospitable for parasites, which are the most common health offenders in recreational water.
New data from the Centers for Disease Control show that there were 57 disease outbreaks from public swimming pools in the United States from 2009 to 2010, resulting in 1,030 illnesses and 40 hospitalizations. Most of the outbreaks occurred either in hotels or waterparks.
Precise causes could not be confirmed in some cases, but in 24 of the 57, a specific parasite, Cryptosporidium, was responsible. A hearty little organism, Cryptosporidium is highly resistant to chlorine, the element regularly used to disinfect pools. Though difficult to get rid of, the parasite is not overly harmful to healthy humans. Some people show no symptoms of infection at all. In those that do, diarrhea, cramps, and – occasionally – fever are what they contend with, but these generally last no longer than seven days.
States also reported 24 disease outbreaks from untreated recreational water venues such as lakes, sickening another 296 people. Half of these outbreaks were confirmed or suspected of being caused by cyanobacterial toxins emitted from algae.
The number of disease outbreaks from recreational water is likely far underreported, but even if every instance were documented, public swimming pools would still come out looking squeaky clean. Judging on available evidence, the stereotype that public pools are slosh pits of disease doesn't hold water. 301 million people over the age of six swim in public pools each year, and a mere .0004% come home with an infection, and a minor one at that.
Source: CDC. Recreational Water–Associated Disease Outbreaks — United States, 2009–2010. MMRW 10 Jan. 2014 / 63(01);6-10