Federal health officials have significantly narrowed their investigation into a multistate outbreak of cyclosporiasis after tracing illnesses to a specific supply chain of shredded iceberg lettuce served at Taco Bell restaurants in five states. The investigation, led by the U.S. Food and Drug Administration in coordination with the Centers for Disease Control and Prevention and state health agencies, marks an important step in determining the source of an outbreak that has affected hundreds of people across multiple states.
According to federal investigators, traceback efforts identified a common source of shredded iceberg lettuce distributed to Taco Bell locations in Indiana, Kentucky, Michigan, Ohio, and West Virginia where many of the reported illnesses occurred. The FDA’s investigation followed distribution records from restaurants through food service distributors and processors before identifying a single supply chain linked to the affected locations.
The agency has confirmed that the investigation is centered on shredded iceberg lettuce originating from central Mexico. While the FDA has not publicly identified the supplier in its official investigation updates, multiple national news organizations have reported that the company involved has voluntarily cooperated with investigators and requested that customers remove the implicated product from distribution while the investigation continues.
Federal officials emphasized that the investigation remains active. Investigators are continuing to determine whether the same supply chain provided shredded iceberg lettuce to additional restaurants, institutional food service operations, or other commercial customers beyond those already identified. As additional shipping records and distribution documents are reviewed, the list of affected locations or products could expand if evidence supports further action.
The investigation highlights the extensive process federal agencies use to trace fresh produce through the nation’s food distribution network. Because leafy vegetables often move through multiple distributors, processing facilities, and transportation companies before reaching restaurants, investigators rely on invoices, shipping manifests, purchase records, and supplier documentation to reconstruct the movement of products from the point of service back to their source.
Tracing fresh produce presents unique challenges during foodborne illness investigations because many products are consumed or discarded long before illnesses are diagnosed. Cyclospora infections typically develop several days to two weeks after contaminated food is eaten, creating a delay between exposure and the start of public health investigations. By the time patients seek medical care, laboratory testing confirms the illness, and investigators begin interviewing those affected, the original food product is often no longer available for laboratory testing.
As a result, federal investigators depend heavily on epidemiological interviews and traceback records rather than physical testing of the food itself. By comparing the meals consumed by large numbers of patients and identifying common ingredients served through shared distribution systems, investigators can narrow their focus to specific products and supply chains.
Cyclospora is a microscopic parasite that causes the intestinal illness known as cyclosporiasis. The infection commonly produces prolonged watery diarrhea, stomach cramps, nausea, fatigue, decreased appetite, and weight loss. Unlike many bacterial foodborne illnesses, Cyclospora cannot spread directly from one person to another because the parasite must first mature in the environment before becoming capable of causing infection.
Health officials note that effective treatment is available, although symptoms may persist for several weeks if left untreated. Medical providers generally diagnose the illness through specialized laboratory testing, as routine stool examinations may not always detect the parasite.
At this stage of the investigation, federal agencies have not advised consumers to avoid all iceberg lettuce sold in the United States. Instead, the investigation remains focused on a specific distribution chain involving shredded iceberg lettuce supplied to certain Taco Bell restaurants. Officials continue to evaluate whether additional products or customers received lettuce from the same source and whether any broader public health recommendations are warranted.
The FDA, CDC, and state health departments continue to work together as the investigation progresses. Additional traceback findings, product information, or public health advisories may be released as investigators complete their review of distribution records and determine whether the affected supply chain extends beyond the restaurants already identified. Until that work is complete, federal officials continue to characterize the investigation as ongoing while monitoring for additional confirmed illnesses linked to the outbreak.