Cyclospora outbreak: Former FDA food safety chief says skip this lettuce

A former Food and Drug Administration (FDA) food safety chief is advising consumers to steer clear of bagged salads as cyclospora infections continue to surge nationwide, warning that contamination can easily spread across prepackaged leafy greens.

Susan Mayne, a professor of epidemiology at the Yale School of Public Health and former director of the FDA’s Center for Food Safety and Applied Nutrition, issued the caution during an interview with CBS News on Sunday.

The advice coincides with an ongoing investigation into a massive multistate outbreak of cyclosporiasis, a gastrointestinal illness triggered by the microscopic parasite Cyclospora cayetanensis. Most commonly tied to fresh produce like leafy greens, herbs, and berries, the parasite induces prolonged bouts of watery diarrhea, severe cramping, and fatigue.

While investigators are still working to identify the source of the current outbreak, former FDA food safety officials and public health experts say consumers may want to take extra precautions with higher-risk foods until more information becomes available.

Newsweek reached out to the FDA and the Centers for Disease Control and Prevention (CDC) by email for comment.

The Latest on the Cyclospora Outbreak in the U.S.

According to the Centers for Disease Control and Prevention (CDC), the U.S. has recorded 4,173 confirmed cases of cyclosporiasis since May, alongside 7,100 unconfirmed reports. State-level counts are frequently higher because health departments aggregate both confirmed and probable cases; Michigan alone has logged 8,176 cases.

The outbreak ranks among the largest on record in the U.S. Federal officials previously linked a cluster of 1,947 illnesses across nine states to Taylor Farms shredded iceberg lettuce.

However, a Taylor Farms spokesperson told Newsweek on Saturday that “there are no confirmed positive sample results for product testing for Cyclospora as of July 24, 2026.”

“We are passionate about helping people live healthier lives through fresh produce, and the safety of our food is paramount. We maintain best-in-class Cyclospora prevention protocols and invest more than $200 million annually into our independently audited and verified food safety protocols,” the spokesperson said. “When questions were raised about the source of the recent Cyclospora outbreak, we immediately removed all potentially implicated product from the marketplace, and out of an abundance of caution we issued an even broader recall of all iceberg lettuce sourced from the region. We have also voluntarily suspended all iceberg lettuce sourcing and production from central Mexico.”

Taylor Farms has enlisted independent experts to review safety protocols at its central Mexico facility, where production has been temporarily halted since July 18.

“We are confident in our food and food safety systems and will continue to be transparent as more information becomes available,” the spokesperson added.

The FDA is investigating another cyclospora outbreak that has not yet been traced to a specific item, although lettuce, parsley and cilantro are among the top suspects.

‘Avoid Bagged Salad’

Despite Taylor Farms’ voluntary recall of shredded iceberg lettuce from Central Mexico, Mayne urged consumers to bypass bagged salads.

“We’ve never seen anything like this,” Mayne, who ran the food-safety department of the FDA from 2015-23, said. “This is just an astonishingly large outbreak, record-setting outbreak.” She added: “I would avoid the bagged salads. And the reason is that a little bit of contamination can be spread more broadly through bagged salads.”

The outbreak has also drawn attention to the federal government’s foodborne illness monitoring efforts. Mayne said that food safety efforts in the U.S. have been under resourced for decades. In July 2025, the Foodborne Diseases Active Surveillance Network, known as FoodNet, a collaboration between the CDC, 10 state health departments, and the USDA, reduced a program that tracked food poisoning infections, including those caused by cyclospora.

While U.S. Department of Health and Human Services Secretary Robert F. Kennedy, Jr. said only redundant surveillance programs were cut, Mayne said that wasn’t true.

“Clearly, there have been cuts,” she told CBS News.

What Is Cyclospora?

Cyclospora is a microscopic parasite known as Cyclospora cayetanensis that causes an intestinal illness called cyclosporiasis. People become infected after consuming contaminated food or water, most often fresh produce exposed to fecal contamination.

“It could be inadequate bathroom facilities, inadequate hand-washing facilities,” Mayne said when asked how the parasite could get onto lettuce. “Somehow that water is getting contaminated from some other source–sewage, some other source.”

The illness is best known for causing prolonged watery or explosive diarrhea, but patients can also experience severe stomach cramps, nausea, bloating, weight loss, fatigue, loss of appetite and recurrent gastrointestinal symptoms. Symptoms can appear up to two weeks after exposure and can persist for weeks or months without treatment.

Cyclospora is not typically spread directly from one person to another because the parasite must first mature in the environment before becoming infectious. That characteristic can make outbreaks especially difficult to trace and contain.

Doctors typically treat cyclospora with the antibiotic trimethoprim-sulfamethoxazole, commonly known as Bactrim. While most people recover fully, severe dehydration and prolonged illness can occur, particularly among vulnerable populations.

Cyclosporiasis Outbreak

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