Summer Kick-Off Reminder About Crypto

In time for the Memorial Day weekend, the US Centers for Disease Control and Prevention (CDC) released a report indicating that 1 in 3 swimming-related disease outbreaks in the United States occurs in hotels. The top pathogens responsible for the outbreaks were listed as, Cryptosporidium (also known as “Crypto”), Pseudomonas, and Legionella.

The microscopic parasite Cryptosporidium, commonly known as “crypto,” can infect animals, and some Cryptosporidium species can also infect humans. Crypto is the leading cause of water-borne disease in humans in the United States. Because of the parasite’s protective outer shell, Cryptosporidium can live outside of a host for a prolonged period time and even persist in chlorinated pools when an infected person or animal sheds the parasite through their stool; therefore, contaminated pools and other recreational water locations are a common source of the parasite.

Michele Hlavsa, RN, MPH, chief of CDC’s Healthy Swimming Program shared in the recent report that, “Swallowing just a mouthful of water with Crypto in it can make otherwise healthy kids and adults sick for weeks with watery diarrhea, stomach cramps, nausea, and vomiting.”

Symptoms usually begin within 2 to 10 days after infection. Although symptoms can continue for up to 30 days, infected individuals shed the parasite once their symptoms begin and can continue to do so for weeks after the symptoms have subsided.

According to the recent report from the CDC, there has been “mixed progress in preventing outbreaks caused by germs spread through treated recreational water.” A total of 493 outbreaks of these infections were reported between 2000 and 2014 in a total of 46 states and Puerto Rico. The outbreaks caused 8 deaths and at least 27,219 illnesses. A total of 32% of the outbreaks were in hotels.

About 58% of the confirmed outbreaks “where a germ was identified linked to pools, hot tubs, and water playgrounds,” as well as 89% of illnesses were linked with crypto. Legionella was responsible for about 16% of the outbreaks and can cause flu-like symptoms or pneumonia. Pseudomonas was behind another 13% of the outbreaks and is linked with folliculitis and even otitis externa.

The CDC indicates that “more than half of outbreaks started in the summer, the peak season for swimming.”

Due to the high chlorine tolerance of Cryptosporidium, the CDC recommends that officials in charge of pools and other facilities found to carry the parasite follow hyperchlorination water treatment guidelines in the event of fecal contamination or an outbreak. The CDC also urges anyone infected to avoid pools and other water facilities. “To help protect your family and friends from Crypto and other diarrhea-causing germs, do not swim or let your kids swim if sick with diarrhea,” said the Chief of the CDC’s Healthy Swimming Program, Michele Hlavsa, RN, MPH.

Cryptosporidium can live for up to 10 days in properly treated water.

Furthermore, improperly cleaned environments can encourage biofilm growth in which Legionella and Pseudomonas can thrive. Once biofilms have developed, the area is even harder to clean. Specific cleaning recommendations from the CDC are available in their Model Aquatic Health Code.

The CDC provided the following tips to stay safe and healthy:

• Don’t swim or let your kids swim if sick with diarrhea. If Crypto is the cause of diarrhea, wait until 2 weeks after diarrhea has stopped to go swimming.
• Check the pools, hot tubs, and water playground inspection scores.
• Before getting in the water, use a test strip from your local retailer or pool supply store to check if the water’s pH and bromine or free chlorine level are correct.
• Don’t swallow the water.
• Take kids on bathroom breaks hourly, and change diapers in a diaper-changing area and away from the water.

An earlier version of this article was published May 23, 2017. The content has been updated with the latest available information from the CDC