You might dub it “produce paranoia.” On social media, videos show people clearing out their fridges, swearing off salads and debating whether it’s safe to eat cilantro.
It’s the frantic but expected internet response to the surge in cases of a diarrhea-causing parasite that’s rapidly spreading across the US, as health officials investigate whether salad greens may be contributing to the outbreak.
As of Tuesday, the US Centers for Disease Control and Prevention had received reports of 1,645 laboratory-confirmed domestic cases of cyclosporiasis and is investigating 5,100 additional reports. Cases of the “explosive diarrhea parasite” have been reported across 34 states, with Michigan among the hardest-hit regions.
The gastrointestinal illness is caused by cyclospora, a foodborne pathogen that’s difficult to trace but has historically been linked to fresh produce such as berries and lettuce. As of yet, no specific food, brand, grower or supplier has been conclusively identified as the source of the outbreak.
That hasn’t stopped people from panicking, oversharing and making a whole lot of dark memes. With any health scare, bad advice and myths spread just as fast as the actual illness. So we turned to healthcare experts to learn the facts.
“I wouldn’t necessarily suggest that people avoid produce,” said Dr. John Openshaw, an infectious disease physician and medical epidemiologist at Stanford University. “Even though the number of people involved in the current outbreak or outbreaks seems large, overall the risk remains very low to most people.”
What is cyclosporiasis?
Cyclosporiasis is caused by cyclospora cayetanensis, a microscopic parasite transmitted through fecal matter that infects the small intestine. According to infectious disease experts at Johns Hopkins, it takes only a few microscopic Cyclospora eggs to hijack your gastrointestinal tract.
In the US, previous cyclospora outbreaks have frequently been associated with fresh produce, including bagged salad mixes, cilantro, basil, raspberries, snow peas and green onions. Any food that’s contaminated and eaten uncooked can theoretically transmit cyclospora.
Unlike some stomach illnesses, such as norovirus, cyclosporiasis is unlikely to spread directly from one person to another. After the parasite leaves an infected person’s body, it generally needs at least one to two weeks in the environment before it becomes infectious.
Health officials says it’s best to avoid bagged greens or precut mixes to stay safe during the current cyclospora outbreak.
How can you reduce your risk?
So far, only lettuce and salad greens have emerged as a possible source, and the CDC says no specific brand, grower, supplier, restaurant or grocery store has been identified.
As of Tuesday, there was no nationwide recommendation to throw away lettuce. However, Michigan health officials have issued more specific guidance for lettuce during the current investigation, including buying whole heads of lettuce instead of bagged lettuce or premixed salad kits (then discarding the outer three layers of leaves) and cooking leafy greens when practical.
Though washing fresh produce might reduce your exposure to cyclospora and other foodborne contaminants, it can’t guarantee the parasite will be completely removed.
“Washing produce does not meaningfully decrease the risk of Cyclospora, and heat remains the gold standard for risk reduction,” Steier said. Cooking vegetables at an internal temperature of 158 degrees Fahrenheit or higher is the only surefire way to kill the parasite.
Experts also warn against using soap, bleach or household disinfectants on produce. Fruits and vegetables can absorb soap and detergent, which may make you sick, and the CDC says routine chemical disinfection is unlikely to kill cyclospora.
Household tools or countertop items like a UV produce washer, ultrasonic cleaner or ozone device won’t make contaminated food safe to consume, either. Steier confirmed that none of those methods has sufficient real-world evidence to support their use in killing the parasite.
What should you do if you have symptoms?
Experts advise contacting a healthcare provider if you develop persistent watery diarrhea, especially if it is severe, lasts longer than a week, or goes away and then returns. Drinking fluids is also important because prolonged diarrhea can cause dehydration.
Diagnosing cyclospora requires special lab testing, and the parasite isn’t included in routine stool testing. The CDC says patients sometimes need to provide multiple samples because cyclospora can be difficult to detect.
The standard treatment is the prescription antibiotic combination trimethoprim-sulfamethoxazole, commonly sold under the brand names Bactrim and Septra. People who are allergic to sulfa drugs should discuss other options with a medical professional.
