FDA Probing New Cyclospora Outbreak Not Linked to Lettuce: Reports
Federal health officials are investigating a new outbreak of Cyclospora infections as the United States confronts an unusually active season for the foodborne parasite.
The latest cluster involves 72 illnesses and was added to the Food and Drug Administration’s active outbreak investigation list on July 22. The agency has not identified the contaminated product or disclosed where the illnesses occurred, but investigators have begun tracing the food supply chain in an effort to locate the source.
The new investigation is separate from the much larger outbreak linked to iceberg lettuce supplied by Taylor Farms de Mexico.
“This is an active investigation, and officials are working together to determine the specific cause of illnesses in this cluster,” the Department of Health and Human Services said regarding the 72-person outbreak.
The growing number of investigations presents another public-health challenge during President Donald Trump’s second term, while raising broader questions about food-safety enforcement, imported produce and the government’s ability to identify contamination before products reach American consumers.
Separate Lettuce Outbreak Expands
The Centers for Disease Control and Prevention announced Friday that the separate outbreak connected to iceberg lettuce had expanded to nine states: Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania and West Virginia.
At least 1,947 illnesses and 98 hospitalizations have been connected to that outbreak. No deaths have been reported.
Taylor Farms de Mexico recalled all iceberg lettuce sourced from central Mexico on July 17. The recalled lettuce was distributed to consumers, restaurants and retailers in at least 27 states.
The recall included Marketside-branded iceberg salad and shredded lettuce products sold at Walmart, along with multiple products distributed to food-service customers. Federal officials have advised consumers not to eat the recalled lettuce and to discard it or return it to the place of purchase.
The FDA’s investigation found that sick individuals had reported eating at Taco Bell restaurants that received shredded iceberg lettuce from the Mexican supplier. Taco Bell stopped using lettuce from Taylor Farms de Mexico on July 17.
Although an initial lettuce sample was described as positive for Cyclospora, FDA laboratory specialists later determined that the result was a false positive.
Officials stressed that the faulty laboratory result did not undermine the epidemiological and traceback evidence connecting the outbreak to shredded iceberg lettuce produced by Taylor Farms de Mexico. As of July 19, the FDA had not obtained a confirmed positive product sample, but its investigation continued to converge on the supplier and growers in central Mexico.
Multiple Investigations Remain Open
The FDA’s active investigation table currently lists six separate Cyclospora investigations.
In addition to the 72-person cluster and the lettuce-linked outbreak, officials are investigating unidentified food sources connected to clusters involving 10, 18, two and eight illnesses. Some of those outbreaks are considered over, but the FDA’s work to identify their sources remains active.
Cyclospora is a microscopic parasite that causes an intestinal illness known as cyclosporiasis. Infections are generally associated with food or water contaminated by the parasite, with domestically acquired cases frequently connected to fresh produce.
Symptoms can include watery diarrhea, loss of appetite, fatigue, nausea, cramping, bloating and weight loss. They normally begin about one week after exposure, although the incubation period can range from two days to two weeks or longer.
The disease is unlikely to spread directly from one person to another. Instead, officials focus on identifying contaminated food, water or agricultural practices that may have exposed consumers.
Parasite Is Particularly Difficult to Trace
Cyclospora investigations are more difficult than many traditional foodborne-illness investigations because symptoms may not begin until long after the contaminated food was consumed.
Investigations involving Cyclospora outbreaks “take a significant amount of time,” Gwen Biggerstaff, deputy director of the CDC’s Division of Foodborne, Waterborne, and Environmental Diseases, said during a July briefing.
By the time a patient becomes sick, seeks medical treatment, receives specialized testing and speaks with investigators, the food responsible for the infection may have already disappeared from stores, restaurants and homes.
The parasite also cannot currently be examined using the same whole-genome sequencing procedures commonly used to match bacterial illnesses to contaminated products.
Instead, investigators rely on targeted genotyping, which Biggerstaff said is “useful for detection but not as fast and precise as whole genome sequencing” when officials are attempting to connect illnesses with a particular food source.
Routine stool tests also do not always screen for Cyclospora. Patients suffering from prolonged symptoms may need to specifically request testing, another factor that can contribute to undercounting and delayed investigations.
Cases Far Above Normal Levels
Federal officials reported on July 14 that at least 1,645 laboratory-confirmed domestically acquired Cyclospora infections had been recorded since May 1.
The CDC was also reviewing more than 5,100 additional reports to determine whether they met the agency’s case definition. At that time, illnesses had been reported across 34 states.
Officials warned that the real number of infections was likely higher because some people experience mild symptoms, recover without medical treatment or are never tested for the parasite.
The CDC said the country was experiencing both elevated infections nationally and several more concentrated outbreaks that may have different food sources.
Those distinctions are important. Not every reported Cyclospora infection is connected to Taylor Farms lettuce, and officials have explicitly stated that they are investigating other illnesses unrelated to the iceberg-lettuce outbreak.
Food Security Demands Accountability
Consumers have been advised to wash their hands and rinse fresh produce thoroughly under running water before cutting, preparing or eating it. However, the CDC cautions that washing alone cannot guarantee the removal of Cyclospora.
Cooking produce to at least 158 degrees Fahrenheit, or 70 degrees Celsius, can kill the parasite. Cut, peeled or cooked fruits and vegetables should also be refrigerated promptly, while surfaces that touched recalled lettuce should be washed and sanitized.
The immediate priority is identifying the source of the new 72-person outbreak and ensuring that any contaminated food still on the market is removed.
The broader issue, however, involves the security and transparency of America’s food supply.
When produce is imported and distributed across dozens of states before contamination is discovered, federal regulators must be capable of tracing it rapidly, informing consumers clearly and holding suppliers accountable.
American families should not have to guess whether the food on their tables is safe. Strong inspections, transparent supply chains and firm standards for both foreign and domestic producers are basic responsibilities of a government charged with protecting the public.