An outbreak of diarrhea from a parasite is surging. Here’s what to eat and what to avoid

Cases of diarrhea caused by the parasite cyclospora continue to climb, and with the threat of weeks of illness and the lack of certainty about its source, it’s easy to wonder: Is anything in the produce aisle safe to eat?

An outbreak has reached more than 4,000 cases and more than 100 hospitalizations Michigan isolated and linked to cases in Ohio, West Virginia and Kentucky. Michigan health officials said their research showed lettuce or salad greens may be the culprit, but other foods cannot be ruled out and no specific species, growers or suppliers have been identified as the source.

Nearly 7,000 cases have been confirmed or are under investigation in 34 states nationwide since May 1, the U.S. Centers for Disease Control and Prevention said Tuesday. It’s unclear whether cases linked to the large outbreak in the Midwest are appearing in more states.

While Michigan health officials are urging shoppers to be especially careful when buying and eating lettuce and greens this summer, federal health officials are emphasizing staying up to date on health warnings and using standard safety practices when washing food.

“Cyclospora is a very interesting organism. It’s a parasite, so it’s been historically linked to epidemics in the past, often foodborne epidemics,” said Dr. Nuwan GunawardhanaHe is a hospital epidemiologist and physician at Columbia University Irving Medical Center who specializes in infectious diseases.

“It’s not actually thought to be contagious from person to person,” he said. “When we talk about foodborne outbreaks of Cyclospora, it’s a very resilient organism and so it has the ability to stick to surfaces very, very well with our fresh produce and fruit.”

Who is most at risk

Cyclosporiasis is an intestinal disease caused by the microscopic parasite cyclospora, and symptoms, including prolonged watery diarrhea, stomach cramps, nausea, fatigue, loss of appetite, and weight loss, typically develop about two days to two weeks after exposure. Although the infection can be treated with a combination of antibiotics, if left untreated the illness can last for weeks and cause dehydration.

Approximately 1 in every 11 cases is hospitalized, According to data reported to the CDC. No deaths were reported.

Director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center, Dr. “Those most at risk are young children, elderly individuals, and people with compromised immune systems,” said Dan Barouch.

“In most otherwise healthy people, the disease is usually mild,” he said. “While it makes sense to take precautions, especially for people at high risk, there is no need to panic at this stage.”

However, for those wondering which foods are safe, there are some simple steps to take both at the market and at home.

Foods to avoid

When shopping for lettuce or other greens, experts recommend avoiding pre-cut or packaged produce and instead choosing whole, uncut produce because they typically undergo less processing.

Bagged salad mixes and kits have been linked to previous cyclospora outbreaks, particularly in the United States and Canada, according to Michigan health officials.

On Tuesday, fast food chain Taco Bell also said it would remove some items from the menu at some locations as a precaution.

“It’s probably a good idea to avoid bagged lettuce products and bagged salad products for now,” Barouch said. “And if these are desired, rewash them at home, even if they have been washed before, because the true source of the outbreak is not yet known.” he said.

Raspberries, basil, salad mixes such as vegetable trays and coleslaw, cilantro, fruit and berry mixes, lettuce and peas have all been linked to outbreaks in the past.

It is also recommended to avoid fruits and vegetables that are bruised, damaged or may be mouldy.

As the outbreak continues, people with compromised immune systems “may want to avoid eating fresh produce altogether until a culprit is identified, given that this particular population is at higher risk for severe disease,” Gunawardhana said.

Food to buy

But all fruits and vegetables, including leafy greens, should not be avoided completely, he said, because they are still an important part of a healthy diet. Don Stoeckelenvironmental microbiologist, Produce Security Alliance and is a long-term collaborator of the Cornell National Good Agricultural Practices Program.

“My personal risk threshold allows me to continue eating what I normally eat, with a little more care in preparation, because I know that the vast majority of fresh fruits and vegetables on the market are safe to consume, regardless of the source of the pathogen,” Stoeckel said in an email.

Michigan health officials recommend purchasing whole head lettuce. It is also recommended to discard the outer two to three layers of the leaves and wash the remaining inner leaves thoroughly before use.

“If you’re eating produce that you can peel, that’s also the best way to prevent ingestion of these organisms, because when you peel fruits or vegetables, you’re also getting rid of contaminated surfaces,” Gunawardhana says. he said.

Wrong way to wash

Proper washing is also an important step in reducing the risk of foodborne illness; However, it is not recommended to wash the products with soap, bleach or commercial household cleaners as they are not for food use and may leave harmful residues.

“Stay away from soaps, detergents, or other additives that are not intended to be eaten. Dilute disinfectants are not effective against protozoan pathogens such as Cyclospora and may cause more harm than good,” Stoeckel said.

Gunawardhana also said that chlorine is not recommended for washing.

“People think maybe chlorinated tablets might work, but actually cyclospora is quite resistant to chlorine and that’s another thing to be aware of,” he said.

CDC says “Remember that chemically disinfecting or sanitizing products may not completely eliminate Cyclospora. It is important to wash products thoroughly, even if labeled as pre-washed.”

The correct way to wash

Gunawardhana said there are three steps people can take to wash their products thoroughly before use:

• Wash your hands with soap and water.

• Place your product under clean running water.

• Increase friction by physically rubbing or brushing hard produce, such as cucumbers, melons, and potatoes, with your hands or a brush.

“This doesn’t prevent it 100%, but it can help,” Gunawardhana said.

Although washing can help reduce contamination, experts warn that it cannot guarantee complete removal of cyclospora, especially from leafy greens, herbs and delicate fruits.

But washing “increases protection when combined with cooking or peeling,” Michigan health officials said in a press release Monday.

Dr. D., deputy director of the CDC’s Division of Foodborne, Waterborne and Environmental Diseases. Gwen Biggerstaff said at a briefing on Tuesday that the advice she would share with the public was what she would tell her family and friends.

“This is my best advice: to follow our current food safety practices and guidelines and stay up to date on food safety alerts and research updates so they know which foods are safe and how to keep their families safe and protected,” Biggerstaff said.

Prioritize cooking

As the outbreak continues, it may be helpful to prioritize cooking foods to reduce your risk. Cooking food to an internal temperature of 158 degrees Fahrenheit or higher kills cyclospora, accordingly 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 prevent getting sick from this particular organism is to cook it really thoroughly,” Gunawardhana said. “Cooking food to at least 70 degrees Celsius or 158 degrees Fahrenheit is the best way to kill this organism.”

Food safety experts also emphasize preventing cross-contamination in the kitchen. Keep unwashed produce separate from ready-to-eat foods, raw meat, poultry or seafood.

“The universal advice, not just during outbreaks, is to practice good hygiene in food preparation areas at all times,” Stoeckel wrote.

“Keeping work surfaces clean, including hand washing, to prevent cross-contamination from one food item to another. When food-safe, cooking (to about 160 F) kills pathogens before consumption,” he said. “Washing and peeling some produce will reduce the risk, but neither process removes everything on the surface of fresh produce. Even small amounts of the pathogen can cause illness if consumed.”

For more CNN news and newsletters, create an account at: CNN.com