In December 2019 the CDC, public health and regulatory officials in several states, and Canada and the US Food and Drug Administration investigated a multistate outbreak of E. coli O157:H7 infections linked to Fresh Express Sunflower Crisp chopped salad kit. In the US, 11 people infected with the outbreak strain of E. coli O157:H7 were reported by 5 states. Illnesses started on dates ranging from November 5, 2019 to November 16, 2019. Four people were hospitalized. One person developed hemolytic uremic syndrome (HUS). There were no deaths.

Information collected as of December 9, 2019 indicated that Fresh Express Sunflower Crisp Chopped Salad Kit was the source of this outbreak. This outbreak, an outbreak in Washington state, and a larger multi-state outbreak linked to romaine lettuce from the Salinas, CA growing region all shared a common supplier with ranches in Salinas. Although this grower was determined to be a common supplier for all three outbreaks based on available supply chain information the FDA said that the romaine lettuce from this grower did not explain all the illnesses seen in the three outbreaks.

On January 15, 2020 the CDC declared the outbreak to be over.

As of December 11, 2019, Canada reported 24 outbreak associated cases residing in 6 Eastern provinces.