TWIN CITIES, MN — The Minnesota Department of Health is investigating an outbreak of E. coli O157 infections associated with the Minnesota State Fair. Disease investigators recently identified 11 cases among Minnesota residents who visited the Minnesota State Fair prior to becoming ill.

The ill people reported having visited the fair between Aug. 25 and Sept. 2, and becoming ill between Aug. 29 and Sept. 6. Cases range in age from 2 to 43 years. Six of the ill people were hospitalized, and one developed hemolytic uremic syndrome, a potentially fatal complication. One person remains hospitalized, according to a news release.

MDH is working in partnership with fair officials to determine the source of the outbreak. Evidence gathered to date suggests that contact with livestock is the most likely factor. Most of the ill people reported visiting the Miracle of Birth exhibit and having contact with calves, goats, sheep or piglets.

However, some cases did not have direct contact with animals and may have been exposed through contact with contaminated surfaces (e.g., fence rails). This serves as a strong reminder to always wash your hands after being around livestock and their enclosures. Preliminary laboratory tests of the bacteria (done by whole genome sequencing) from several of the cases indicate the E. coli O157 strains are closely related. Additional testing will be conducted to try to pinpoint the source of the infections.

MDH State Public Health Veterinarian Joni Scheftel said that while there is little chance of ongoing exposure since the fair has ended, the potential health impacts of E. coli O157 make it important to spread the news so health care providers are aware and anyone with symptoms of infection get proper treatment.

"These infections can have serious health impacts and there is always a chance that an ill person can pass along the infection to others through close contact," Scheftel said in a statement.

"Anyone who believes they may have developed an E. coli O157 infection should contact their health care provider. E. coli O157 infections should not be treated with antibiotics, as this might lead to serious complications." Symptoms of E. coli O157 infection typically include stomach cramps and diarrhea, often with bloody stools, but only a low-grade or no fever. People typically become ill two to five days after exposure, but this can range from one to eight days. Most people recover in five to 10 days.