For many, swimming is a favorite pastime of summer, especially while on vacation. However, as noted by CNN,1 what may be lurking in your hotel pool and/or hot tub might literally turn your stomach. In this case, it's a diarrheal disease caused by microscopic parasites, giving teeth to the phrase "What you can't see can hurt you."
Waterborne Parasite Infections Are on the Rise
Infectious disease specialist Jaime Zapata from University Hospital in San Antonio explains the most common symptoms telling you something is definitely wrong include "… cramps, nausea, vomiting, fever, dehydration, so be aware that if you go to the swimming pool, shower after."
That's good advice, according to CNN's Susan Scutti, who notes that so far this year, while that particular hospital hasn't yet seen a case of Cryptosporidium, often dubbed "Crypto," (not to be confused with the currency) the Centers for Disease Control and Prevention (CDC) is worried, and it's no wonder:
"Hotels set the stage for nearly a third of all disease outbreaks in the United States linked to chlorinated or treated water — such as pools and hot tubs — between 2000 and 2014, according to a new government report. During that 15-year period, a total of 493 outbreaks linked to treated recreational water were reported in 46 states and Puerto Rico, the report indicates."2
The CDC also breaks down numbers for the years between 2009-2010 compared to 2011-2012: There were 24 outbreaks and 90 outbreaks, respectively, from swimming in recreational waters such as pools and other bodies of water in the U.S., and half of the culprits found in pool water were Crypto.
Outbreaks are described as occurring when two or more people who become ill are linked by location and time frame to the same body of water. The average time before someone infected by the parasite becomes sick is seven days, but it can range between two and 10. Serious cases can also infect your respiratory tract.
Statistics and Other Data on Crypto
According to the CDC's Morbidity and Mortality Weekly Report,3,4,5 between 2000 and 2014, a total of 493 disease outbreaks were sourced to public pools and hot tubs — 32 percent of which were traced back to hotels.6 In all, these waterborne outbreaks led to 27,219 illnesses and eight deaths.
Crypto was the primary culprit in these cases, accounting for nearly 60 percent of pool-related outbreaks. Six of the eight deaths and 16 percent of the illnesses were associated with bacterial Legionella, a sometimes-fatal pneumonia, which you may remember was the cause of a massive outbreak in 1976 called Legionnaires' disease.
Pontiac fever, which causes mild flu symptoms, is another bacterial disease from a bacteria implicated in those cases, as is folliculitis ("hot tub rash") and otitis externa ("swimmers' ear"), from a bacteria known as Pseudomonas. Legionella and Pseudomonas can both tolerate disinfectants and retain their ability to make people sick for longer than you would think. About half of the outbreaks were between June and August, with a smaller peak in March. The CDC also states:
"Chlorine inactivates most pathogens within minutes although extremely chlorine-tolerant Cryptosporidium can survive for (more than) seven days (and) is transmitted when a diarrheal incident (i.e., a high-risk Cryptosporidium contamination event) occurs in the water and the contaminated water is ingested.
The parasite's extreme chlorine tolerance enables it to persist in water, cause outbreaks that sicken thousands, and spread to multiple recreational water venues and other settings (e.g., child care settings)."7
Crypto has made a name for itself in the U.S over the last two decades as one of the most common causes of waterborne disease, and not just pools and hot tubs but drinking water as well. It should be noted that the parasite can be found in every area of the U.S. and throughout the world. Needless to say, washing your hands thoroughly and often becomes more urgent once you're aware that such diseases are caused by a parasite that's basically spread through exposure to feces.
It spreads when you touch your mouth with contaminated hands. Contamination comes with touching objects that perhaps others touched with infected hands, from stair railings to elevator buttons to doorknobs to baby toys. The CDC also notes that you're not always able to tell by looking at something if it's been in contact with fecal matter.