CDC, public health and regulatory officials in several states, the U.S. Food and Drug Administration (FDA), and the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS) collected and analyzed different types of data but were unable to identify the food source of this multistate outbreak of E. coli O157:H7 infections.

A total of 22 people infected with the outbreak strain were reported from 7 states. Of 20 people with information available 11 were hospitalized. Of 18 people with information, 3 developed a type of kidney failure called hemolytic uremic syndrome (HUS). One death was reported from Washington.

State and local public health officials interviewed people about the foods they ate in the week before they got sick. CDC analyzed the interview data and did not identify a specific food item as a potential source of this outbreak. People reported eating a variety of food items, including leafy greens, broccoli, cucumbers, and strawberries. However, none of the food items were reported significantly more by sick people in this outbreak when compared to healthy people in the FoodNet population survey.

WGS also showed that this outbreak strain was previously linked to various sources, including romaine lettuce and recreational water.

FDA conducted traceback investigations on several produce items but did not identify a common source or potential point of contamination.

The outbreak was declared over on March 11, 2021.