One in Three Swimming-Related Disease Outbreaks Linked To Hotels: CDC

Hotel swimming pools and hot tubs are a major source of disease outbreaks in the United States, according to the findings of a new report published by federal health officials. 

In the latest issue of the U.S. Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report, researchers indicate that one-third of all swimming-related outbreaks appear to come from bacteria in hotel pools or spas.

As part of Healthy and Safe Swimming Week, which begins May 21, the CDC released the findings of a study conducted on illnesses linked to community pools and water parks from 2000 to 2014. During that time 493 outbreaks occurred, causing more than 27,000 illnesses and resulting in eight deaths.

One in three waterborne disease outbreaks during that time were traced back to hotel pools or hot tubs. Waterparks were also determined to be a major source of illness, the report notes.

Three of the primary bacteria that cause outbreaks include Cryptosporidium (or Crypto), Pseudomonas, and Legionella.

Crypto is a parasite that can survive in pools that have been properly maintained with chlorine and other bacteria killing chemicals. Most bacteria are killed in minutes with the recommended levels of chlorine put in pools. Crypto can survive for seven days at those levels. It requires high amounts of chlorine for long periods of time to kill it.

Approximately 58% of diarrheal-related outbreaks are caused by crypto, resulting in 89% of illnesses. More than half of outbreaks began during the summer, which is peak swimming season because of the heat.

Crypto spreads easily in the water when someone who has the parasite and has diarrhea swims in a pool. It’s also not easy to detect contaminated pool water with the naked eye, even when the cause is a diarrheal accident. The large amount of water in the pool dilutes it.

A person who swallows only one small mouthful of pool water can become sick with the parasite. It can make a person sick for several weeks, causing diarrhea, stomach cramps, nausea, and vomiting.

“Chlorine cannot kill Crypto quickly,” warned Michele Hlavsa, R.N., M.P.H., chief of CDC’s Healthy Swimming Program. “We need to keep it out of the water in the first place. Don’t go into the water, and don’t let your kids go into the water, if sick with diarrhea.”

Legionella and Pseudomonas are the next most leading cause of outbreaks. Legionella caused 16% of outbreaks and six of the eight deaths. Pseudomonas caused 13% of outbreaks.

Pseudomonas and Legionella bacteria are often found in the slimy areas of a pool where biofilm accumulates. The bacteria can survive disinfectants used in hot tubs, pools and water playgrounds.

Legionella outbreaks often cause symptoms similar to the flu. Pseudomonas tends to cause skin infections, rashes, and swimmer’s ear.

It is easy for bacteria to grow when pools, hot tubs, and water playgrounds are not cleaned properly. Biofilm accumulates, and bacteria grows in the biofilms, making it even harder for disinfectants to kill it.

The CDC report also indicated 20% of pools and spas did not have enough disinfectant when inspected.

Researchers warn that the elderly, current and former smokers, people with chronic lung diseases, and those with weakened immune systems are more likely to get sick from Legionella.

Anyone experiencing symptoms of any of these diseases, and who has had recent pool or hot tub contact, should see a doctor right away.

The CDC recommends following these tips to help keep you or your children from becoming ill:

• If you or your children are sick or have diarrhea, don’t swim in pools or community water.
• If you are certain crypto is the cause of the diarrhea, wait a full two weeks after the diarrhea has stopped to go swimming again.
• Check pools, hot tubs, and water playground inspection scores before swimming.
• Use test strips from pool supply companies to check the water’s pH, bromine, and free chlorine levels.
• Don’t swallow water while swimming.
• Take children on frequent bathroom breaks and change diapers in changing areas away from the water.