Threat of Cryptosporidium In Pools

Ultraviolet (UV) light is increasingly being used as an effective barrier for Cryptosporidium and other emerging chlorine resistant organisms. In the United States many pool and leisure operators are now installing this technology as standard to ensure their water does not pose a risk to public health. This article examines the dangers posed by Cryptosporidium and how Ultraviolet disinfection can minimise the risk of an outbreak.

Understanding the problem:

Found in water supplies all over the globe, Cryptosporidium outbreaks are now becoming more and more frequent causing severe illness that can be fatal to vulnerable groups such as the young and elderly and in a number of cases has lead to costly and drawn out legal action. (New York State)

The problem is, while disinfection with chlorine effectively destroys other pathogens - it takes less than one minute to eradicate E. coli, and approximately 16 minutes to kill the Hepatitis A virus - cryptosporidium is virtually immune. Due to a thick outer membrane, it takes more than 10 days to destroy cryptosporidium in a normal pool (25 degrees Celsius with free chlorine levels of 1ppm, a pH of 7.5 and no chlorine stabilisers) according to the U.S. Centre of Disease Control.

The most common forms of the pathogen are Cryptosporidium C. homius or Cryptosporidium paravum, commonly found in livestock. Both cause severe gastrointestinal symptoms in humans, including diarrhea, stomach cramps, vomiting and nausea, which can lead to fever and excessive dehydration. Infections typically last between one and two weeks, but some e.g. those with a weaker immune system such as the very old or the very young, may develop more severe or chronic symptoms leading fatalities.

Cryptosporidium propagates itself by using its host to spread oocysts (think eggs) that then infect others. These oocysts latch onto cells in the intestinal tract, where the parasite reproduces. It then exits the body through the stool ready to infect another person. In swimming pools, cryptosporidium is generally spread via diarrhea (accidents), which release millions of crypto oocysts into a pool environment at a time. Because it takes only 10 to 30 occysts to become infected, simple bad hygiene such as not washing hands after using the toilet or changing a diaper could cause an outbreak.

Minimising the risks:

The most significant step any leisure operator can take to avoid an outbreak of Cryptosporidium is education. By informing users of the risks and the action that they can take, such as showering before entering the pool, washing their hands after using the toilet and avoiding pool use during and after periods of sickness, operators can vastly reduce the risk of introducing Cryptosporidium into the pool environment. However, no amount of education will protect users from outbreak once pool water becomes infected.

Considered the best technology to achieve protection, Ultraviolet disinfection systems are now being used widely as an effective barrier against Cryptosporidium and any other form of bacteria or virus. Unlike Chemical treatments such as Chlorine and Bromine, UV has the ability to destroy the DNA contained in the nucleus of all living organisms.

When properly applied, UV light at wavelengths of 265 nm (known as UVC light) is absorbed by the DNA and permanent damage is caused. Once exposed to UVC light, the DNA quickly stops normal cell functions, rendering the organism non viable. Replication is prevented and the organism quickly dies. No species have demonstrated an ability to become resistant to UV, unlike chemical disinfectants where a growing number of organisms have become increasingly tolerant.

Case Study - State of New York  Turns to Validated UV systems for Cryptosporidium Solution:

Following major outbreaks throughout the US, Cryptosporidium has now become a major concern for the  pool and  leisure industry.  Due to the chemically resistant nature of Cryptosporidium, and the scale of health problems caused by the highly infectious parasite, the need for increased protection was further forced to the top of the agenda, when over 4000 patrons in Upstate New York became seriously infected with Cryptosporidium, and consequently took out legal action.

The outbreak was tracked to a splash pad  at one of the State of New York's parks, where traditional methods of treatment, relying solely on using chlorine and filtration had failed to provide adequate protection against the Cyrpto parasite, whose thick outer membrane makes it highly resistant to traditional chemical disinfection methods such as chlorine and bromine.

So large was the scale of the problem, the New York Department of Health decided to re-think their entire pool water treatment strategy, and called upon their own experience in the drinking water industry to find a solution to this growing threat.  The New York Department of Health concluded that the risk of an outbreak, as with drinking water could be greatly reduced by the use of "Ultraviolet water treatment systems."

Working closely with Engineered Treatment Systems LLC, the New York Department of Health developed stringent testing protocol for UV systems to safeguard public health.  Additionally, ETS  biodose tested a number of the UV systems, gaining regulatory validated approval for their effectiveness against Cryptosporidium and other water borne pathogens. Ultimately the inclusion of UV treatment systems is now firmly entrenched within New York's pool safety legislation.  A decision already being investigated and adopted by forward thinking regulatos from may states across the USA, trying to avoid the costly ramifications associated with an outbreak.

Section 6-3.11 section 3 of the New York pool safety regulation states:

"Ultraviolet light disinfection is required in addition to an approved Chemical disinfectant."

ETS, with over 25yrs of experience and achievement, is a world leader in Ultraviolet technology. Strong commitment to innovation and development means that ETG's range of UV products offers customers the best choice available when quality, reliability and consistency need to come as standard. The full range of Validated ETS UV disinfection systems, plus service, support and spares are available now from ETS  and their fully trained distributors.