What lies beneath: Protect yourself before diving into swimming pools
The change in weather heralded by Memorial Day Weekend traditionally marks the beginning of the swimming pool and water park season. • As children and adults frolic in the water, it is important to understand how such activities can potentially lead to infectious diseases and how to minimize those risks.
If you have diarrhea, do not enter the pool
I have increasingly seen placards with this message posted outside of swimming pools and, to me, it is a quite obvious admonition that does not require a sign — but evidently it does. The Centers for Disease Control and Prevention (CDC) reports that more than 1 in 5 American adults does not recognize the inherent danger of swimming with diarrhea . The message of this sign is that a plethora of potentially dangerous pathogens — ranging from E.coli to norovirus to cryptosporidium — can find their way into the mouths of swimmers when individuals experiencing diarrhea or who are emitting fecal matter enter the water. A similar risk exists for infants and toddlers whose diapers leak.
Chlorination is the standard mechanism used for keeping these illnesses at bay but is not a panacea. Certain organisms and parasites can live up to 10 days in an adequately chlorinated pool. Additionally, chlorine's capacity to kill germs is not instantaneous and is dependent on such factors as its concentration and pH.
In fact, having fecal germs in the pool is the norm, as the CDC demonstrated in a 2012 study in which more than 75 percent of 161 Georgia public swimming pool filters examined revealed an organism of interest.
It is also important to realize that splash parks, backyard swimming pools, plastic kiddie pools, and whitewater parks may also present similar risks.
In 2010-2011, 90 recreational water outbreaks involving more than 1,700 people were reported to the CDC from 32 states and Puerto Rico. More than three quarters of these outbreaks involved treated water. Hospitalizations occurred in 5 percent of the infected and one death occurred.
The symptoms of these infections vary but can include nausea, vomiting, diarrhea and abdominal cramps. Most are self-limited infections but serious complications, including kidney failure and even death, have occurred particularly with E.coli infections.
How to protect yourself
There are several preventive actions that can help to decrease the risk that is inherent in recreational water activities. People should shower before entering a pool to remove residual fecal matter as well as remove oil and other substances from the skin which interfere with the action of chlorine; check pool inspection records; do not swallow the water; do not enter the pool if you have diarrhea or vomiting; give children regular bathroom breaks; regularly check diapers; and use waterproof bandages.
The summer water park season is a fun time that, as a child, I always looked forward to. The fact that these activities are linked to outbreaks of infectious disease is a completely preventable risk that simple actions can easily eliminate.
Dr. Adalja, a Pittsburgh-based infectious disease physician, is a senior scholar at the Johns Hopkins Center for Health Security. Follow him on Twitter: @AmeshAA.