The number of new cases of cyclosporiasis in Ohio continues to drop, with 422 added in Ohio added in the past week, down from 503 last week amid a nationwide outbreak in 47 states.
As of Aug. 20, the Ohio Department of Health is reporting 5,874 cases of cyclosporiasis, a gastrointestinal illness caused by a parasite known as cyclospora cayatenensis, in 84 counties so far in 2026. That's up from 5,452 cases in 84 counties as of Aug. 6. All but nine of the cases occurred since June 20.
But the rate of increase has been slowing down over the past several weeks. ODH reported an increase of 1,437 cases from July 24 to 30. New cases dropped the following week, with 936 reported from July 31 to Aug. 6. And the numbers dropped again from Aug. 7 to 13,
with 503 new diagnoses before the latest decrease.
Ohio and Michigan have led the charge in reporting cyclosporiasis incidents, with Michigan's health department stating on Aug. 20 that it had 14,277 cases, including the first two deaths identified in the nationwide outbreak.
Nationwide, the outbreak linked to iceberg lettuce expanded to six additional states, bringing to total to 15. The CDC, which lags significantly behind states in reporting infections, has pinpointed 15,716 laboratory-confirmed cases across 47 states between May 1 and its latest update Aug. 17. Thousands more have not yet been confirmed by laboratories.
Cyclospora outbreak tied to lettuce expands to 15 states
Not all of the cyclosporiasis clusters have been linked to the same source, however. The largest outbreak, centered in Michigan, was traced by the Food and Drug Administration through Taco Bell back to recalled iceberg lettuce grown by produce giant Taylor Farms in central Mexico.
On July 24, the Taylor Farms-related outbreak was identified as reaching nine states: Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania and West Virginia.
It has since expanded to include Missouri, Arkansas, Iowa, Nebraska, New Hampshire and North Carolina, according to the CDC. At least 6,358 cases were confirmed as being part of the lettuce-related outbreak, up from fewer than 2,000 on July 24.
The FDA has not yet identified the source of additional outbreaks.
The source of a cyclosporiasis cluster is more difficult to track than other foodborne illnesses due to a long incubation period, difficulty obtaining samples and the inability to use the same genetic tracking tools available for pathogens like E. coli and listeria.
Which Ohio counties are hit by cyclosporiasis?
These are the counties reporting cyclosporiasis cases as of Aug. 13, and the number of cases, according to ODH:
- Adams: 1
- Allen: 10
- Ashland: 22
- Ashtabula: 91
- Athens: 4
- Auglaize: 5
- Belmont: 3
- Brown: 1
- Butler: 29
- Carroll: 19
- Champaign: 2
- Clark: 12
- Clermont: 8
- Columbiana: 29
- Coshocton: 4
- Crawford: 41
- Cuyahoga: 763
- Darke: 10
- Defiance: 155
- Delaware: 19
- Erie: 150
- Fairfield: 32
- Fayette: 2
- Franklin: 164
- Fulton: 188
- Gallia: 14
- Geauga: 40
- Greene: 24
- Hamilton: 52
- Hancock: 13
- Hardin: 10
- Harrison: 2
- Henry: 100
- Highland: 5
- Holmes: 3
- Huron: 134
- Jackson: 13
- Jefferson: 15
- Knox: 5
- Lake: 112
- Lawrence: 17
- Licking: 42
- Logan: 4
- Lorain: 361
- Lucas: 845
- Madison: 3
- Mahoning: 61
- Marion: 9
- Medina: 163
- Meigs: 5
- Mercer: 19
- Miami: 9
- Monroe: 1
- Montgomery: 49
- Morgan: 3
- Morrow: 24
- Muskingum: 6
- Noble: 1
- Ottawa: 57
- Paulding: 87
- Pickaway: 4
- Pike: 1
- Portage: 205
- Preble: 7
- Putnam: 9
- Richland: 39
- Ross: 31
- Sandusky: 328
- Scioto: 13
- Seneca: 35
- Shelby: 3
- Stark: 146
- Summit: 203
- Trumbull: 45
- Tuscarawas: 26
- Union: 15
- Van Wert: 10
- Vinton: 3
- Warren: 14
- Washington: 5
- Wayne: 42
- Williams: 33
- Wood: 529
- Wyandot: 53
- Unknown county: 3
How do I know if I have cyclosporiasis? Symptoms, testing
Symptoms of cyclosporiasis may include:
- Explosive, watery diarrhea (most common)
- Loss of appetite
- Weight loss
- Cramping
- Bloating
- Increased gas
- Nausea
- Fatigue
Less common symptoms may include:
- Vomiting
- Body aches
- Headache
- Low-grade fever
- 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:
- Wash hands with soap and water before and after handling or preparing raw fruits and vegetables.
- Wash all fruits and vegetables thoroughly under running water before eating, cutting or cooking.
- Scrub firm fruits and vegetables, such as melons and cucumbers, with a clean produce brush.
- Cut away any damaged or bruised areas on fruits and vegetables before preparing and eating.
- Refrigerate cut, peeled or cooked fruits and vegetables as soon as possible (within two hours).
This article originally appeared on USA TODAY: New Ohio cases of illness caused by cyclospora parasite fall again
