A new study from Australia suggests that swimming in public pools or local lakes increases the risk of catching the stomach flu or other diseases due to infection, most notably gastroenteritis.

After over 15 months of research following more than 2,800 adults and children, researchers discovered that the participants were more likely to get gastroenteritis in a week or so after taking a public swim.

The study found that the participants’ gastroenteritis risk was one-quarter higher in the one or so weeks after visiting a public pool or spa compared to non-swimming weeks. On average, after swimming in a lake or river, the odds rose to 77 percent.

“There are two types of gastroenteritis, mainly the viral and the bacterial,” H. Tak Cheung, director and professor of the school of biological sciences, said.

“The virus type usually leads to inflammation of the lining of the gastrointestinal tract due to the invasion of the virus on those cells. It is frequently associated with fever, vomiting, diarrhea, stomach cramps and abdominal pain. A fever is the primary signal that it is a viral type,” Cheung said.

Recreational swimming has been linked to causing illness to the extent that swimming can raise odds of getting sick to an unknown level.

“In the United States, [getting sick] is not something most have to worry about. When it comes to swimming in a swimming pool, the water is constantly treated and tested. Swimming in a lake can be a little more of a concern, but due to the low density of people swimming in lakes it is not as high as one would imagine,” Cheung said.

Contaminated food and drinking water are sources of infection, but Bob Quandt, professor of chemistry, explains another source.

“Areas of lakes that have been polluted are polluted by biological agents. Though most are safe, there are always risks,” Quandt said.

“There are some basic risks if you are swimming in lakes. One being that there is the man-made stuff from industries such as factories that dump their contaminates into local lakes,” Quandt said.

No matter the risks, people should not give up swimming. The benefits of swimming, like aerobic exercise, are greater when compared to the risk of catching gastroenteritis.

There is a need, however, for better preventative measures, according to the study.

When it comes to taking safety measures Cheung lays out one simple rule to follow.

“If any safety measures should be taken it should be just to avoid swimming in waters [if] one is not so sure if it is heavily contaminated or not,” Cheung said.