In August 2022, Tennessee Department of Health officials investigated an outbreak of E. coli O157:H7 associated with milk from a herd share dairy farm. Two infants tested positive for Shiga Toxin E. coli (STEC) by polymerase chain reaction. Both infants were hospitalized. One infant developed Hemolytic Uremic Syndrome (HUS) and was hospitalized for 27 days. Three probable cases were also identified. No deaths were reported.

The cases all lived in households that consumed raw milk acquired from the same cow-share program. A site visit and environmental assessment were conducted on August 15. The dairy farm included seven to 10 cows that were hand-milked daily. Observations identified possible routes of fecal contamination during milking and possible milk storage at temperatures higher than recommended.

A US Department of Agriculture laboratory identified two isolates of E. coli O157:H7 from a single cattle manure sample in the dairy farm's milking bar. Whole genome sequencing conducted by the Tennessee Department of Health Laboratory Services showed that human and cattle stool isolates were highly related with zero allele differences detected.