A cyclospora outbreak is causing widespread illness, with over 7,000 cases nationally and 4,000+ in the Midwest, potentially linked to lettuce or salad greens. The parasite causes prolonged diarrhea and other severe symptoms, particularly in vulnerable populations. While health officials urge caution, advising against pre-cut greens and emphasizing thorough washing and cooking, they also stress that most produce remains safe and part of a healthy diet. Learn how to protect yourself and what foods to avoid or prioritize.
Cases of diarrhea caused by the parasite cyclospora continue to climb, and with the threat of weekslong illness and no certainty about the source, it’s easy to wonder: Is there anything in the produce aisle that’s safe to eat?The outbreak has risen to more than 4,000 cases in Michigan and Ohio, and linked to cases in West Virginia and Kentucky. Michigan health officials said their investigation suggests that lettuce or salad greens may be the culprit, but other foods can’t be ruled out — and no specific type, grower or supplier has been identified as the source.Nationally, more than 7,000 cases have been confirmed or are under investigation, in 34 states since May 1, the US Centers for Disease Control and Prevention said Tuesday. It’s not clear which states are seeing cases connected to the large outbreak in the Midwest.While Michigan health officials urge shoppers to be especially careful when purchasing and eating lettuce and greens this summer, federal health officials are emphasizing staying up to date on health alerts and using standard safety practices when washing food.“Cyclospora is a very interesting organism. It’s a parasite, so it’s historically been linked to outbreaks in the past, usually foodborne outbreaks,” said Dr. Nuwan Gunawardhana, a hospital epidemiologist and physician who specializes in infectious diseases at Columbia University Irving Medical Center.“It’s not really considered contagious from person to person,” he said. “When we’re talking about foodborne outbreaks with cyclospora, it’s a very hardy organism, and so it has the ability to adhere to the surfaces very, very well with our fresh produce and fruit.”Who’s most at riskCyclosporiasis is the intestinal illness caused by the microscopic parasite cyclospora, and symptoms typically develop about two days to two weeks after exposure, including prolonged watery diarrhea, stomach cramps, nausea, fatigue, loss of appetite and weight loss. Although the infection can be treated with a combination antibiotic, the illness can last weeks if left untreated and may lead to dehydration.About 1 in every 11 cases has been hospitalized, according to data reported to CDC. No deaths have been reported.“Those most at risk are young children, elderly individuals and immunosuppressed people,” said Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center.“In most other healthy people, disease is often mild,” he said. “While it makes sense to take precautions, particularly for people at higher risk, there’s no reason for panic at this stage.”But for people wondering what foods are safe to eat, there are some simple steps to take, both at the grocery store and at home.Foods to avoidWhen shopping for lettuce or other greens, experts recommend avoiding precut or packaged items and selecting whole, uncut produce instead, because it typically undergoes less handling.Bagged salad mixes and kits have been specifically linked to previous cyclospora outbreaks in the United States and Canada, according to Michigan health officials.On Tuesday, fast food chain Taco Bell also said it’s removing some ingredients from its menu at some locations as a precaution.“It’s probably a good idea to avoid bagged lettuce products and bagged salad products for now. And if those are desired, then to rewash them at home, even if they come prewashed, because the actual source of the outbreak is not yet known,” Barouch said.Raspberries, basil, salad mixes — like vegetable trays and coleslaw — cilantro, berry and fruit mixes, lettuce and snap peas have all been linked to outbreaks in the past.It’s also recommended to avoid fruits and vegetables that may be bruised, damaged or moldy.While the outbreak is ongoing, people with weakened immune systems “may want to avoid eating fresh produce altogether until a culprit is determined, given that this particular population is at a higher risk for severe disease,” Gunawardhana said.Foods to buyBut whole fruits and vegetables, including leafy greens, should not be avoided completely because they are still an important part of a healthy diet, said Don Stoeckel, an environmental microbiologist, associate at the Produce Safety Alliance and long-term collaborator with the Cornell National Good Agricultural Practices Program.“My personal risk threshold allows me to continue eating what I normally eat, with a little more caution about preparation, because I know that — whatever the source of the pathogen is — the vast majority of fresh fruits and vegetables on the market are safe to consume,” Stoeckel said in an email.Michigan health officials suggest purchasing whole head lettuce. It’s also recommended to discard the outer two to three layers of the leaves and thoroughly wash the remaining inner leaves before using.“If you are eating produce that you’re able to peel, that’s also a very optimal way to prevent ingesting these organisms, because when you’re peeling the fruits or vegetables, you’re getting rid of the contaminated surfaces as well,” Gunawardhana said.The wrong way to washProper washing also is an important step to reduce the risk of foodborne illnesses – but it’s not recommended to wash produce with soap, bleach or commercial household cleaners, as they are not intended for food and may leave harmful residues.“Stay away from soaps and detergents or other additives that are not meant to be eaten. Dilute sanitizers are not effective against protozoan pathogens like Cyclospora and could cause more harm than good,” Stoeckel said.Gunawardhana also said chlorine is not recommended for washing.“People think that maybe chlorinated tablets might help, but actually, cyclospora is highly resistant to chlorine, and so that’s just another thing to be aware of,” he said.The CDC says to “Be aware that chemically disinfecting or sanitizing produce might not fully eliminate Cyclospora. It is important to thoroughly wash produce even if it is labeled as pre-washed.”The right way to washGunawardhana said there are three steps people can take to thoroughly wash their produce before using it:“This won’t 100% prevent it, but it might help,” Gunawardhana said.While washing helps reduce contamination, experts caution that it cannot guarantee complete removal of cyclospora, particularly from leafy greens, herbs and delicate berries.But washing “enhances protection when combined with cooking or peeling,” Michigan health officials said in a news release Monday.In a briefing on Tuesday, Dr. Gwen Biggerstaff, CDC’s deputy director of CDC’s Division of Foodborne, Waterborne, and Environmental Diseases, said the advice she’d share with the public is what she’d tell her family and friends.“That’s my best advice: is to follow our standing food safety practices and guidelines, and to stay aware of the food safety alerts and investigation updates, so that they know what foods are safe and they know how to keep their families safe and protected,” Biggerstaff said.Prioritize cookingIt can be helpful to prioritize cooking foods to reduce your risk as the outbreak continues. Cooking food to an internal temperature of 158 degrees Fahrenheit or higher kills cyclospora, according to the Michigan Department of Health and Human Services.Heat can destroy the parasite, making cooked vegetables a lower-risk option than raw produce.“The best way to actually prevent getting sick from this particular organism is really thoroughly cooking it,” Gunawardhana said. “Getting the food to being cooked to at least 70 degrees Celsius or 158 degrees Fahrenheit is the best way to kill off this organism.”Food safety experts also emphasize preventing cross-contamination in the kitchen. Keep unwashed produce separate from ready-to-eat foods and raw meat, poultry or seafood.“Universal advice, not just during outbreaks, is to always practice good hygiene in food preparation areas,” Stoeckel wrote.“Keeping work surfaces clean, including hand washing, to prevent cross-contamination from one food item to another. When appropriate to the food, cooking (to about 160 F) kills pathogens before consumption,” he said. “Washing, and for some produce peeling, will reduce risk, but neither process will remove everything from the surface of fresh produce. Even small amounts of pathogen, if consumed, can cause illness.”
