Cyclospora outbreak: Is your salad safe to eat

Cyclosporiasis cases are now being reported in nearly every state, with many Americans questioning whether leafy greens should still be a part of their diets or if salads should be avoided until the current Cyclospora outbreak subsides.

According to the Centers for Disease Control and Prevention, there are now more than 18,000 reported cases of the foodborne parasitic illness that can cause severe diarrhea in 45 states. The CDC said iceberg lettuce is the culprit in cases in at least 13 states.

The CDC is investigating other instances of Cyclosporiasis that are unrelated to the current outbreak.

Richelle Guerrero-Wooley, MD, assistant chief of the division of infectious diseases at Loma Linda University Health, said salads are still generally safe to eat.

"The current outbreak is linked to bagged shredded iceberg lettuce from a specific farm and those have been recalled, so make sure those items are still not in your fridge," Guerrero-Wooley said. "Throwing them out is important."

Guerrero-Wooley added that, while a source has been identified, there are still active cases being reported.

A national produce supplier voluntarily recalled iceberg lettuce sourced from central Mexico with officials at The Food and Drug Administration urging consumers, restaurants and retailers to discard any recalled products "immediately."

A federal investigation into the origins of the Cyclospora outbreak is ongoing.

Guerrero-Wooley explained that Cyclospora outbreaks happen every year, typically from May through September, but the number of cases in this year's season is already substantially higher.

Cyclospora is a difficult parasite to remove from produce.

"It is resistant to chlorine, so chlorine-treated water won't kill it," Guerrero-Wooley said. "It is also resistant to industrial pre-washing sprays."

"During the processing of fresh produce, such as shredded lettuce that is processed, washed, and mixed altogether, the parasite easily cross contaminates all of the produce, even if only a small amount is contaminated with it."

Despite Cyclospora being difficult to remove, Guerrero-Wooley said there are precautions consumers can take to help prevent illness, including eating alternative products that offer similar nutrition benefits, like kale, spinach, Swiss chard and cabbage.

Buying whole heads of lettuce is also an option.

"It doesn't 100% guarantee zero risk of infection, but it can lower it by avoiding the handling, processing, and cross-contamination risk with shredded, bagged lettuce," Guerrero-Wooley said.

Heat also kills the parasite.

"Cooking your leafy greens will still give you the opportunity to eat them, and the ability to kill any Cyclospora that might be causing contamination. Heat kills the parasite when heated to at least 158 degrees F or higher." Guerrero-Wooley said.