And in nearly a third of those outbreaks, the infections could be traced back to hotel pools, hot tubs and spas, the CDC says. While most park districts and major water parks adhere to CDC guidelines, Dr. Dorevitch said if you are unsure, ask the pools aquatics director about the protocol to keep the pool clean and safe.
Between 2000 and 2014, the CDC recorded 493 cases of disease outbreaks related to "recreational water" - that is, pools, hot tubs, and water rides (water parks were also included in the calculations). Diarrheal disease outbreaks caused by Cryptosporidium leveled off during 2008 through 2014. It's usually contracted by swallowing pool water, often when it has been contaminated by diarrhea.
Legionella, the source of Legionnaires' disease, is another cause of waterborne diseases that led to six of the eight deaths the CDC reported. But the real problem is the swimmers themselves: if you have a recent wound - say, a cut or a scratch - it's probably best to stay out of the water, lest you pick up an infection through an open wound.
Crypto causes 58 percent of outbreaks where a germ was identified linked to pools, hot tubs, and water playgrounds and 89 percent of the illnesses.
Fifty-eight percent of the total outbreaks were caused by Cryptosporidium, which causes gastrointestinal illness.
The most important way to prevent these outbreaks is to educate swimmers. The annual number of outbreaks caused by Legionella increased around 13 percent per year, the report stated. Legionella can lead to severe pneumonia and flu-like symptoms, while Pseudomonas can result in "hot tub rash" and swimmers' ear, the CDC said. It is harder for disinfectants to kill these bacteria when they are protected by biofilm.
Some people are more likely to get sick from Legionella, including people 50 years or older, current or former smokers, people with chronic lung disease, and people with a weakened immune system. Because of this, the CDC warns individuals to not swim or let your children swim if sick with diarrhea. "If Crypto is confirmed, it's essential to remain out of the water for two weeks".
Check inspection scores of pools, hot tubs and water parks.
Take kids on bathroom breaks hourly, and change diapers in a diaper-changing area and away from the water. It is also important for people to maintain the pools by measuring the chlorine level with test strips.