(This story has been updated to add more information.)
After it said a lettuce sample from Taylor Farms tested positive for cyclospora, the Food and Drug Administration on Sunday said it was a false positive and that there were no confirmed positive sample results, according to Reuters.
The FDA on July 18 had initially reported a lettuce sample from Taylor Farms had tested positive for cyclospora, the parasite that causes cyclosporiasis, an illness that has sickened nearly 1,200 people in Ohio and thousands more across the country.
The July 19 update comes shortly after the FDA advised people in Ohio and four other states to avoid eating lettuce at Taco Bell as the administration believed it to be a source of the cyclospora spread.
“To be clear, at this moment, FDA has not identified a single positive product test result for cyclospora”, Taylor Farms said, according to Reuters.
What is cyclosporiasis? Illness from cyclospora cayatenensis parasite causes explosive diarrhea
Cyclosporiasis is an intestinal illness caused by the microscopic parasite cyclospora cayetanensis, also known as cyclospora, according to the CDC. The illness is not usually life-threatening.
The parasite spreads when people eat food or drink water that was contaminated with feces. People may be at an increased risk for infection when living or traveling in tropical or subtropical regions of the world where cyclosporiasis is regularly occurring.
In the U.S., previous outbreaks of cyclosporiasis have been linked to various types of fresh produce. In 2024, Taylor Farms recalled sliced onions during an E. coli outbreak tied to McDonald’s Quarter Pounder hamburgers, though Taylor Farms said its recall was not connected to Quarter Pounders.
Ohio cyclosporiasis case numbers triple in latest update from health department
Ohio continues to see more new cyclosporiasis cases, with the number more than tripling in a July 16 update from the Ohio Department of Health. Meanwhile, officials attempt to discover where the parasite that causes the illness might be hiding as those infected deal explosive diarrhea and other symptoms.
As of July 16, the Ohio Department of Health reported 1,192 cases of cyclosporiasis, a gastrointestinal illness caused by a parasite known as cyclospora cayatenensis, in 70 counties so far in 2026, with 86 people hospitalized. That’s up from 364 cases in 51 counties as of July 9. All but nine of those cases occurred in June and July, mostly since June 20.
The most cases in Ohio are in Lucas County in the northwest portion of the state, which reports 249, up from 86 the previous week. Wood County, just to the south of Lucas, reports 129 cases, up from 49.
Only Michigan has more cyclosporiasis cases than Ohio, reporting more than 3,300 since June 22, the Detroit Free Press, part of the USA TODAY Network, reported July 14. Nationwide, the U.S. Centers for Disease Control and Prevention have confirmed 1,645 cases of cyclosporiasis with another 5,100 additional cases being investigated.
So far, no source has been confirmed, although Michigan health officials have zeroed in on lettuce and salad greens as a possible source. The CDC has confirmed Ohio, Michigan, West Virginia and Kentucky are linked in a multistate outbreak of the parasite.
These Ohio counties have reported cyclosporiasis cases
These are the counties reporting cyclosporiasis cases as of July 16, and the number of cases, according to ODH:
Ashtabula, Butler, Columbiana, Darke, Defiance, Delaware, Erie, Fayette, Hancock, Harrison, Huron, Logan, Meigs, Mercer, Putnam and Trumbull Counties reported new cases as of July 16, according to the Ohio Department of Health infectious disease dashboard.
How is cyclosporiasis treated? With Bactrim? Does it clear up on its own?
According to the CDC, Trimethoprim-sulfamethoxazole (TMP-SMX), which is sold under the brand names Bactrim, Septra or Cotrim, is the treatment of choice for the illness caused by the parasite.
Sulfamethoxazole and trimethoprim are types of antibiotics used to treat bacterial infections, according to the Cleveland Clinic. Available as a tablet, it belongs to a group of medications called sulfonamide antibiotics.
A cyclosporiasis infection can often clear up on its own in healthy individuals, though symptoms may last several weeks.
States reporting cyclosporiasis illnesses
Ohio remains No. 2 for cyclosporiasis cases nationwide based on the updated numbers on July 16:
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How do I know if I have cyclosporiasis? Symptoms, testing
Symptoms of cyclosporiasis may include:
Less common symptoms may include vomiting, body aches, headache, low-grade fever and other flu-like symptoms.
Symptoms begin about a week after being infected and can last anywhere from a few days to a month or longer without treatment. Some symptoms, such as diarrhea, may go away and then return.
The illness is diagnosed by testing stool samples, according to the CDC.
Cyclosporiasis prevention. How to protect yourself
The CDC says the best way to prevent cyclosporiasis is to avoid food or water that may be contaminated with feces.And to help do that, the agency recommends safe food-handling practices when dealing with produce, including:
This article originally appeared on The Columbus Dispatch: Taylor Farms lettuce sample not positive for cyclospora, Ohio cases rise
Reporting by Jason Rossi and Chad Murphy, USA TODAY NETWORK / The Columbus Dispatch
USA TODAY Network via Reuters Connect
By Jason Rossi and Chad Murphy, USA TODAY NETWORK | USA TODAY Network
