(FOX 13) - The CDC is seeing an increase in reports of infection from a parasite linked to swimming pools and water playgrounds.
The number of reported outbreaks caused by Cryptosporidium - also known as crypto - doubled in 2016, compared to 2014.
The CDC says there have been at least 32 outbreaks of crypto linked to swimming pools or water playgrounds in the United States in 2016, compared with 16 outbreaks in 2014.
The parasite can spread when people swallow something that has come into contact with the feces of a sick person, such as pool water contaminated with diarrhea.
There were 20 crypto outbreaks linked to swimming in 2011, 16 in 2012, and 13 in 2013.
It is not clear whether the number of outbreaks has increased or whether better surveillance and laboratory methods are leading to better outbreak detection. Crypto is the most common cause of diarrheal illness and outbreaks linked to swimming pools or water playgrounds because it is not easily killed by chlorine and can survive up to 10 days in properly treated water.
Swallowing just a mouthful of water contaminated with crypto can make otherwise healthy people sick for up to three weeks with watery diarrhea, stomach cramps, nausea, or vomiting, and can lead to dehydration.
The preliminary data was published in the CDC’s Morbidity and Mortality Weekly Report.