By now, you’ve probably heard of cyclosporiasis. Cases of the gastrointestinal disease caused by the parasite Cyclospora have spiked across the U.S., with more than 11,000 cases reportedly linked to consumption of iceberg lettuce and several thousand more cases without a clear linkage since May across the U.S.

People infected by Cyclospora can experience watery diarrhea, nausea and bloating, among other symptoms. The disease comes from food or water contaminated with the parasite and has historically been linked to contaminated water, fruits, and vegetables. With so much uncertainty around contamination of fresh produce, people have been turning to local farms and farmers markets to buy their produce, hoping that knowing exactly where their food comes from will reduce the chances of eating infected produce. 

Produce contamination by bacteria, viruses and parasites contributes to 46% of foodborne illnesses and 23% of deaths. So to farmers, ensuring that their produce is safe to eat is crucial. Delaware growers plant more than 60,000 acres of fruits and vegetables around the state every year. 

“For my whole family’s operation, produce safety is very important,” said Jared Papen, a Dover area farmer who grows sweet corn and green beans. “Without it, we can’t sell our produce to buyers.”

Papen Farms has been handling produce safely for generations. Papen tests his wells every year to make sure the water he irrigates his crops with is clean and safe. He also makes sure the facility where his produce is packed to be distributed is cleaned every day; the floors are washed morning and night; and all the boxes he packs his produce in never touch the ground.

Papen gained a lot of education on produce safety after completing a food safety course twice in the last few years called the Produce Safety Alliance Training. The University of Delaware College of Agriculture and Natural Resources and UD Cooperative Extension offer this training at least three times a year. The goal is to educate farmers on food safety to reduce the chances of produce contamination on their farms and illness that could be associated with their produce. The training is required for farms over a certain size and gives them up-to-date information in the latest food safety trends.

Nearly 500 farmers in the Delmarva region have completed this training over the last decade. 

Jennifer Jones, produce safety coordinator with UD Extension, said the training leads farmers, food safety professionals, farmers market vendors and others through seven modules that involve hands-on demonstrations and handouts.

Participants learn an introduction to produce safety, worker health hygiene and training, soil amendments, wildlife domestic animal and land use, agricultural water, post-harvest handling and sanitation, and how to develop a farm food safety plan — all with important lessons for keeping produce safe. 

“In one of our modules, we stop and show participants how to hand wash. It’s the simplest thing,” Jones said. “We squirt Glo Germ onto their hands and they rub it in. Then they wash it off. And we use a black light, to see if they washed all the germs off their hands.”

Kali Kniel, Unidel S. Hallock du Pont Chair of Microbial Food Safety, leads some of the training’s modules. Kniel said it’s important to safeguard produce because it’s such a healthy commodity with lots of nutritional value. 

Most fresh produce, like lettuce and berries, is consumed raw. Heating something up through cooking can kill bacteria and parasites, which means raw produce is more susceptible to contamination without this kill step.

“Produce is grown outside, where we can’t control lizards and birds and wind and rain and fecal material being blown over from a nearby farm operation,” Kniel said. “So it’s really about farmers putting in every step they can to reduce the risk that that product could be contaminated.”

Kniel said it’s important for farmers to always know “one step forward and one step back” on where their produce is, so in the case there is a recall related to a food safety issue, they could trace any possible links of contamination to their produce. Any produce that needs to be recalled and isn’t sold impacts a producer’s bottom line. 

“If you know one step forward and one step back, you can make sure that a market is selling your product in the timing it's supposed to,” Kniel said, “so that it's not sitting in the shelf or was forgotten in the back of the refrigerator.”

Kniel said there are a lot of scientific knowledge gaps surrounding the transmission of Cyclospora on farms. The Produce Safety Alliance Training provides growers with solid information on using microbiologically safe water and how to reduce risks in complicated farm environments. 

“While there is great uncertainty about how Cyclospora originally may have contaminated the iceberg lettuce and other produce commodities, growers should continue to develop comprehensive food safety programs that focus on prevention and risk management,” Kniel said. “This is important and must never be replaced by product or water testing. You cannot test your way to food safety.”

The next Produce Safety Alliance Training will be offered in winter 2026-2027, once growers have completed their harvest and have more time to spend in the classroom.

If you need any information on produce safety,  please contact Kali Kniel at kniel@udel.edu or Jennifer Jones at jbjones@udel.edu.