A parasite called Cyclospora has sickened people across 17 states, with 145 reported cases and 20 hospitalizations recorded between May 1 and June 16, according to the Centers for Disease Control and Prevention.

The CDC data shows no deaths have been reported during that period.

Dr. Amesh Adalja with the Center for Health Security at the Johns Hopkins Bloomberg School of Public Health says eating produce exposed to contaminated water can allow the parasite to enter the body.

"They invade the intestine, causing diarrhea, which can be watery, cause abdominal cramps and may last for several weeks," Adalja said.

Experts say Cyclospora tends to contaminate raw fruits and vegetables every summer. The parasite is not considered a new threat.

"For this particular outbreak, they haven't found the common source yet," Adalja said. "There may be more than one source."

Adalja says washing produce won't eliminate the threat but can reduce the risk. Firm fruits and vegetables like melons and cucumbers should be scrubbed with a clean produce brush under running water before eating, cutting or cooking.

Cutting away any damaged or bruised areas on produce before preparing and eating is also recommended. Any cut, peeled or cooked produce should be refrigerated within two hours.

Cooking fruits and vegetables can also lower risk.

"The best thing you can do is be judicious about where you're getting your produce from, washing it as best you can and then being on the alert for any symptoms that occur," Adalja said.