Swimming pools and water parks are great places to be active, have fun and cool off. They’re also places where germs can spread and cause serious illnesses.

Contrary to popular belief, chlorine and other disinfectants don’t kill germs instantly. It can take minutes — and up to days — for chlorine to kill them. Swallowing just a little water that contains germs can cause diarrhea-related illnesses such as cryptosporidium, giardia and shigella.

According to the Centers for Disease Control and Prevention, twice as many people contracted cryptosporidium, also known as crypto, in 2016 than in 2014. Last year, at least 32 outbreaks occurred in 13 states. While Kansas wasn’t one of those states, Dr. Thomas Marcellino, of Mt. Oread Family Practice and Douglas County’s health officer, said it’s important to be proactive in preventing swimming pool illnesses.

“If you have young kids and they are in diapers, you can help prevent spread of illnesses by making them wear their swim diapers in the pool,” Marcellino said. “If there’s an accident, make sure you notify the proper authorities, so they can get people out and then clean and sanitize the pool.”

Marcellino said it’s also important to not swallow water in pools, lakes and rivers, and to wash your hands before eating. “Try not to go back and forth between water and eating without washing hands,” he advised. He also said it’s important to keep food away from the water. Marcellino said it’s also important to not swallow water in pools, lakes and rivers. Marcellino said he became sick with giardia one time during a canoe trip because he had a bag of carrots in the canoe and he hadn’t realized that the river water was splashing on them.

Marcellino said residents should contact their health care provider if they have diarrhea lasting more than two days or any fever, abdominal pain or bloody stools. He said treatment for such illnesses depends on the individual.

“Antibiotics are not always needed, but may be recommended for some cases,” he said. “Hydration and supportive care are important.”

In 2003, Douglas County had an outbreak of crypto. There were 96 laboratory-confirmed cases and the people who were infected ranged from 1 year old to 70 years old. Additionally, there were 600 probable cases, meaning a laboratory did not confirm them, but residents were reporting diarrhea.

County health official Mary Beverly said once someone has crypto from accidentally swallowing contaminated food or water or having contact with other contaminated objects, the illness can easily spread from person to person within a household or day care.

“Once introduced into a community, crypto can be spread for months if the public is not vigilant about practicing healthy habits, such as hand washing and staying out of swimming pools when sick,” said Beverly, who is director of epidemiology and environmental public health at the Lawrence-Douglas County Health Department.

To help prevent the spread of recreational water illnesses, the health department monitors and investigates outbreaks, in cooperation with health care providers and the Kansas Department of Health and Environment. It also provides inspections of swimming pools and spas at 86 locations, which include apartment complexes, hotels and fitness centers — as well as city and school pools.

Beverly encourages everyone to do his or her part to keep the water safe for swimming.

“We want everyone to have a fun and safe summer,” she said.