The Athens City-County Health Department in southeast Ohio said on Wednesday, November 11, 2026, that it is investigating four laboratory-confirmed cases of Shiga toxin-producing E. coli (STEC) in Athens County. The department said its staff are working to identify how the infections occurred, whether there is a common source, and whether any risk to the public continues. The Athens Messenger first reported the announcement.

What the health department has said

• Four cases, all laboratory confirmed as STEC.
• No source has been identified. The department notes that STEC can spread through contaminated food or water, contact with animals, or contaminated surfaces.
• People who are sick should wait at least 48 hours after their last episode of vomiting or diarrhea before returning to “in-person classes, work or campus and community events,” and should not prepare food for others during that time. Athens is home to Ohio University. The release does not say whether any of the four people are students.
• People should seek emergency care for diarrhea lasting more than two days, blood in the stool or urine, severe abdominal cramps, frequent vomiting, dehydration, or unusual fatigue, pale skin and easy bruising.

Fatigue, pale skin and easy bruising are among the warning signs of hemolytic uremic syndrome (HUS), the kidney complication that follows some STEC infections, most often in young children. The release does not mention HUS and does not say whether anyone has been hospitalized.

What has not been said

• The serotype: E. coli O157:H7 or one of the non-O157 strains.
• Whether whole genome sequencing shows the four infections are related to one another or to cases elsewhere.
• When the four people became ill, their ages, and whether any were hospitalized.
• Whether the four share a restaurant, event, food, water source or animal contact.
• Whether the Ohio Department of Health has joined the investigation.

STEC is a Class B reportable disease in Ohio. Under the state’s Infectious Disease Control Manual, clinical laboratories send STEC isolates and Shiga toxin-positive specimens to the Ohio Department of Health Laboratory for culture confirmation and molecular analysis. That testing is what will show whether these four cases are an outbreak with a single source.

How four cases compare with the yearly numbers

States report STEC infections to the Centers for Disease Control and Prevention through the National Notifiable Diseases Surveillance System. The counts for the country and for Ohio over the last five years:

Reported STEC cases, United States (excluding territories) and Ohio. Source: CDC National Notifiable Diseases Surveillance System. The 2021 and 2022 figures are from CDC’s finalized annual tables. The 2023 figures are from the final weekly table of 2024, and the 2024 and 2025 figures are from the final weekly table of 2025, which CDC labels provisional.

The 2025 national count is not a real decline. When CDC published its year-end table, Minnesota had reported no 2025 cases, and Missouri and Washington had reported far fewer than the year before.

Ohio’s numbers have climbed for a decade. The Ohio Department of Health’s 2019 Annual Summary of Infectious Diseases counted 265 STEC cases in 2015, 263 in 2016, 287 in 2017, 537 in 2018 and 591 in 2019. The 649 cases reported for 2024 are more than double the 2015 count. Wider use of rapid diagnostic panels that detect non-O157 strains accounts for part of that increase.

Ohio’s 649 cases in 2024 work out to about 5.5 for every 100,000 residents. Athens County has about 62,000 residents. At the statewide rate, the county would expect three or four STEC cases in an entire year. Four confirmed cases at one time is the reason a health department looks for a common source.

The national trend is moving the wrong way as well. Food Safety News reported this week on a study by FDA, CDC and USDA researchers that found STEC incidence rose from 4.6 to 5.7 infections per 100,000 people, against a Healthy People 2030 target of 3.7.

If you are sick

According to the Ohio Department of Health, STEC symptoms begin two to 10 days after exposure, with a median of three to four days. Anyone in Athens County with bloody diarrhea or severe stomach cramps should see a doctor, ask for a stool test, and write down what they ate and where they went in the week before becoming ill. The Athens City-County Health Department can be reached at 740-592-4431.

This post will be updated when the department releases a serotype, case details or a source.