CDC Ends Cyclospora Outbreak Linked to Iceberg Lettuce

The Centers for Disease Control and Prevention (CDC) has announced the conclusion of a significant Cyclospora outbreak. This outbreak, linked to iceberg lettuce, affected 12,883 individuals across 21 states. It led to 570 hospitalizations and resulted in two fatalities.

According to reports, Taylor Farms de Mexico was identified as the supplier of the contaminated iceberg lettuce. On July 17, the company issued a recall for their iceberg lettuce sourced from central Mexico. Currently, the CDC states that these lettuce products are no longer available in stores or restaurants, minimizing the risk of further cyclosporiasis illnesses from this particular source.

The Broader Cyclospora Issue

The outbreak represents only a portion of a broader increase in Cyclospora cayetanensis infections. Since May 1, there have been 19,595 confirmed domestic cases across 49 states and Washington, D.C. This includes 1,043 hospitalizations and two deaths. The CDC’s latest data provides a geographical representation of where patients resided, although it does not pinpoint where they came into contact with the parasite.

While officials identified contaminated iceberg lettuce as the outbreak source, the exact contamination cause remains under investigation by the Food and Drug Administration (FDA). Additionally, multiple cyclosporiasis clusters are still under scrutiny, alongside ongoing outbreaks linked to Salmonella, E. coli, and Listeria pathogens.

Investigating the Cyclospora Outbreak Cause

An association with iceberg lettuce emerged from patient interviews and supply-chain tracing, rather than from conclusive laboratory tests. Investigations centered around Taco Bell restaurant patrons, where Michigan officials analyzed the food histories of 190 individuals. Of those, 90% reported consuming iceberg lettuce. Subsequent tracing by the FDA tied the iceberg lettuce to a single supplier.

An initial positive report from a lettuce sample later proved to be a false positive. As of July 19, the FDA noted the absence of confirmed positive sample results from product testing. Investigators have not publicly pinpointed the contamination source, weighing possibilities such as farm operations, contaminated water, or processing practices. Cyclospora parasites spread via fecal contamination of food or water, and take one to two weeks outside the human body to become infectious, limiting direct person-to-person transmission.

Joint inspections and sampling at Mexican growing operations and processing facilities continue, even as the CDC has closed its outbreak inquiry.

Ongoing Foodborne Outbreak Investigations

The FDA is tracking eight active foodborne outbreaks involving pathogens other than Cyclospora. Here is a summary of these investigations:

• Salmonella Bovismorbificans: Linked to broccoli sprouts, with 22 infections across four states, two hospitalizations, and no fatalities. Evergreen Fresh Sprouts recalled products after testing identified the outbreak strain.
• Salmonella Newport: Investigators have reported 109 cases, with the food source still unidentified. Traceback efforts are ongoing.
• Shiga toxin-producing E. coli and Salmonella Agona: Affecting 55 people in 15 states, with four hospitalizations. Alfalfa sprouts from Everything Sprouts were identified as one source, though not all cases are accounted for. Numerous sprout products have been recalled.
• Salmonella I 4,[5],12:i:-: With 43 recorded cases, the FDA is conducting traceback, inspections, and sampling. No implicated food has been named publicly.
• Salmonella Javiana: Linked to jalapeño peppers, with 431 cases in 32 states. Fifty-seven hospitalizations occurred, prompting recalls of jalapeños from Sinaloa, Mexico, distributed by Coast Citrus Distributors. No fatalities have been reported.
• Listeria monocytogenes: Involves nine cases. Investigators are pursuing traceback, inspections, and sampling, but the food source remains unidentified.
• Salmonella Oranienburg: Tied to 99 cases, with continued inspections, sampling, and traceback efforts underway.
• E. coli O145:H28: Linked to frozen blueberries, with 17 cases in Florida and Georgia and six hospitalizations. Recalls include specific GreenWise frozen berries and Great Value Organic Triple Berry Blend from Walmart. Consumers should check their freezers, as products have 2028 best-by dates.

For more information, Newsweek Editor Edward Pearcey can be contacted.