Cryptosporidium outbreaks have increased in pools and lakes in the United States, according to a new Centers for Disease Control report released Thursday.
From 2011 to 2012, the CDC documented 90 recreational water illnesses that affected 1,788 people and hospitalized at least 95 in 32 states and Puerto Rico. The report found 77 percent of the outbreaks recorded occurred in pools, and of these 52 percent were attributed to Cryptosporidium parvum.
Cryptosporidium is “extremely chlorine resistant”
Cryptosporidium is a parasite that causes serious gastrointestinal illness and survives in water that is chlorinated at typical pool levels.
“This parasite is extremely chlorine-resistant,” Michele Hlavsa, lead author of the report, said to CBS News. “Swimmers bring it into the water when they are sick with diarrhea.”
What is Cryptosporidium?
Cryptosporidium parvum (Crypto) is a protozoan that causes severe gastrointestinal illness that can lead to hospitalization. Cryptosporidiosis is a disease caused by the parasite Cryptosporidium parvum. Crypto, as it is commonly called, is spread through fecal matter (i.e., swim diapers or sick swimmers) and presents a challenge because typical levels of chlorine that are safe to swim in do not destroy it.
When an outbreak occurs, swimmers can become gravely ill, the pool must shut down until the Cryptosporidium is eliminated, and the facility can be exposed to lawsuits to cover medical bills and other expenses. This parasite is common in pools due to young children, swimmers who may have stomach illness, and poor hygiene. People will catch the illness if they drink or swallow contaminated water.
Why is Cryptosporidium a problem for pools?
Cryptosporidium can survive in chlorine-treated pools for more than 10 days because it is covered by an outer shell that protects it from chlorine. Additionally, there is no way to test water for the parasite. The only way to learn of a contaminated pool is if someone who swam there reports becoming sick. This means pools need to take precautions to prevent Cryptosporidium from being introduced in the first place.
In 2016, there were a number of outbreaks in pools across the United States. Below is a list.
- Blountsville, Alabama: The Spring Valley Beach Water Park was closed for a week in August this year due to a presence of the parasite. The park was closed quickly preventing any widespread breakout from happening.
- Raleigh, North Carolina: At least 29 cases were reported by August in Wake County.
- Owatonna, Minnesota: Three different pools were involved in a small outbreak of Cryptosporidium. Extra chlorine was added to the waters and the pools opened back up the following day.
- Phoenix, Arizona: During early August, there was an outbreak declared in Maricopa County with 200 people reported infected. The illness was traced back to 20 pools in the area. Before 2016, there had been less than 200 reported cases combined in the three previous years.
- Columbus, Ohio: In late July there was a mass spread of Cryptosporidium that sickened nearly 1,000 people by fall in the Columbus area. This number exceeded the total combined number of cases in the past four years. This was the largest
Ohio Cryptosporidium outbreak to nearly 1,000
Over 2016, the number of sick people grew to 937 confirmed cases and most track back to exposure at local recreational water facilities, according to Outbreak News. Ohio has the most recorded cases of Cryptosporidium for the year, outpacing Arizona’s outbreak that affected more than 200 people in August.
Cryptosporidium is an increasingly common recreational water illness that causes severe illness and can lead to hospitalization or even death. The protozoan is introduced to public pools through fecal matter, and chlorine at safe swimming levels doesn’t effectively destroy it. Many pools are now opting for secondary or supplemental sanitation pool systems like Clear Comfort that destroy Cryptosporidium and offer swimmers additional protection beyond chlorine.
The Ohio outbreak has not been tied to a single location, and those who have been diagnosed have swam in pools and other aquatic facilities across three counties. As the outbreak continues, health officials are recommending people follow safety measures to prevent spreading the illness further.
Reducing your risk as a swimmer
In addition, the CDC recommends educating staff and patrons in practices that prevent the spread of Cryptosporidium and providing patrons with the following guidelines:
- Don’t swim when you have diarrhea or stomach illness.
- Always shower before entering the pool.
- Wash hands frequently with soap and water.
- Change diapers in a bathroom (not next to the pool).
- Ensure children take frequent bathroom breaks.
- Check swim diapers often.
- Avoid swallowing water.
How can pools protect swimmers from Crypto?
The Centers for Disease Control and Prevention recommends that public pools have a back-up secondary or supplemental sanitizer, chlorine such as AOP, UV or ozone. These systems are an addition to chlorine or salt that effectively inactivates or destroys the parasite if it is introduced to the water.
However, UV only sanitizes the microbes, meaning they are still alive but unable to reproduce. Ozone oxidizes the microbes, but not as effectively as an Hydroxyl-Based AOP (advanced oxidation process) system.
Pool sanitation technology using an Hydroxyl-Based Advanced Oxidation Process offers complete inactivation of Cryptosporidium within one hour. In other words, it destroys the parasite rapidly, returning the pool to a safe swimming environment more quickly.
Moving forward
Increases in instances of Cryptosporidium in public pools across the nation has prompted the Centers for Disease Control and Prevention to recommend that all public recreational water facilities use a secondary sanitation system that will effectively destroy the bacteria. While UV systems are an option, they can be expensive to install and operate and if buildup occurs on the bulb, it doesn’t work effectively.
A more cost and energy-efficient option is a hydroxyl-based advanced oxidation system. Proven to rapidly destroy Crypto, these systems can help you better protect your swimmers.
To learn more about Hydroxyl-Based AOP, watch our video.
Lauren McNitt
Lauren loves swimming during the summer and relaxing in a hot tub after skiing, but the harsh chemicals limit the time she can spend in a pool. She's excited to bring Clear Comfort to others who share her enjoyment of swimming. Lauren is the Director of Marketing for Clear Comfort.
