CDC: 2026 Cyclospora Outbreak is the Largest Ever Recorded

CDC: 2026 Cyclospora Outbreak is the Largest Ever Recorded

I have been following the nationwide outbreak of Cyclospora cayetanensis, a microscopic gut parasite that triggers explosive diarrhea and can be accompanied by severe cramping, nausea, fatigue, and prolonged weeks of illness.

In my last report, I noted that investigators identified Taco Bell’s lettuce supplier, Taylor Farms, as the possible source of the parasite.  This aligns with my projection that, given similar previously recorded events, the Cyclospora spread would likely be tied to fruits or vegetables from a national distributor.

Now the Centers for Disease Control and Prevention (CDC) has revealed that this case count indicates the 2026 Cyclospora outbreak is the largest on record.

Since May 1, there have been 4,173 confirmed domestic cases across 41 states, as well as 767 people who were infected during international travel. The C.D.C. is investigating more than 7,400 additional cases that are not yet confirmed. No deaths have been reported, and 308 people have been hospitalized.

The previous record for confirmed cases was in 2019, when there were 4,703 domestic and internationally acquired infections over the course of the year; the C.D.C. has reported an average of about 2,800 cases per year since 2016.

Health officials are still investigating what’s behind the recent spate of illnesses caused by cyclospora, a parasite transmitted through contaminated food and water. There are likely multiple sources, they say, but they have linked one outbreak of at least 1,644 cases in Michigan, Ohio, West Virginia, Indiana and Kentucky to shredded iceberg lettuce sold by Taylor Farms and grown in central Mexico.

It is anticipated that case numbers will continue to rise, as there is a lag between illness and when a report officially enters the system.

The CDC data shows the ages of those who have fallen ill range between 2 and 95 years old.

There is a six-week reporting lag between when people feel sick and case reporting to the CDC, indicating that numbers will likely continue to rise.

While health officials have linked some of these cases to shredded iceberg lettuce served at Taco Bell restaurants in five states — Indiana, Kentucky, Michigan, Ohio and West Virginia — it is possible there are other potential sources, which officials are investigating.

The lettuce was supplied to Taco Bell by Taylor Farms and sourced from central Mexico.

As federal health officials continue to investigate the source of the massive outbreak of cyclospora, the produce-linked parasite that causes "explosive" diarrhea, they're encouraging people to check their refrigerators for potentially contaminated products.… pic.twitter.com/pGlQwriPz2

— KTLA (@KTLA) July 21, 2026

Mexican officials deny that its lettuce was the source of the outbreak.

But Mexican Health Secretary David Kershenobich said Tuesday at a news conference that his country’s own investigation had not found evidence that the outbreak originated there.

The parasite in question, cyclospora, is notoriously difficult to trace — scientists must use highly sensitive tests to detect it in food. People can also get sick weeks after having eaten contaminated products, so by the time health officials become aware of an outbreak, all of a product worth testing may have been eaten or discarded.

Scientists rely heavily on information about who developed symptoms and what they ate to trace an outbreak to its source. A positive test result is not necessarily needed to determine the culprit.

And, to add to the confusion, the Food and Drug Administration (FDA) announced its findings on the Taylor Farms product were a false positive.

Lettuce supplied by Taylor Farms that initially tested positive for Cyclospora was a false positive, according to the Food and Drug Administration.

The agency said laboratory experts re-reviewed the sample because of the complexity of detecting Cyclospora and determined the result “does not represent true amplification” and should not be considered a confirmed positive.

To clarify, this false-positive lab sample DOES NOT change the basis for FDA’s ongoing outbreak investigation or the overwhelming epidemiological data supporting the current voluntary recall by Taylor Farms.

Over the weekend, FDA alerted Taylor Farms that a new sample of… https://t.co/hedRwhPLd8

— U.S. FDA (@US_FDA) July 20, 2026

Meanwhile, Canada is dealing with its own outbreak of a diarrhea-causing microbe, this one being found in garlic powder.

The 70-gram containers of Heavenly Spices brand garlic powder were recalled due to concerns around possible contamination with the bacteria Bacillus cereus, the Canadian Food Inspection Agency announced on July 15.

“Do not use, sell, serve or distribute the affected product,” the agency’s alert read.

Bacillus cereus is a type of bacteria that causes food poisoning, with symptoms that include vomiting, diarrhea and stomach pains that usually last around two days, according to the Cleveland Clinic.

The bacteria can be found in a variety of foods, such as dairy products, fish, sauces and starchy foods, like rice, pasta and potatoes.

Garlic Powder Recalled Nationwide Due to Risk of Bacterial Contamination That Can Cause Vomiting and Diarrhea https://t.co/XHN9HGyabY

— People (@people) July 21, 2026

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