September 17, 2019
MDH investigating E. coli O157 infections associated with Minnesota State Fair
Evidence gathered to date suggests contact with livestock as key factor
The Minnesota Department of Health (MDH) 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.
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. “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. However, E. coli O157 infections sometimes lead to serious complications like hemolytic uremic syndrome. This syndrome can lead to kidney failure and death. Those most at risk include children under 10 years of age, the elderly, and those with weakened immune systems.
Regardless of the original source of infection, E. coli O157 can be passed from person-to-person through fecal-oral transmission, particularly among families with children still in diapers. Children with diarrhea should not attend child care. Family members and caregivers of recently ill children should wash their hands after changing diapers, going to the bathroom, and before eating. E. coli O157 can be passed in the stool for weeks, and occasionally months, after symptoms resolve.
Approximately 130 cases of E. coli O157 are reported each year in Minnesota. More information on E. coli O157 and how to prevent it can be found on the MDH E. coli website.