The infections have been linked to whole, fresh onions. FDA's traceback investigation is ongoing but has identified ProSource Inc. (also known as ProSource Produce, LLC) of Hailey, Idaho as a source of potentially contaminated whole, fresh onions imported from the State of Chihuahua, Mexico.

The business has agreed to voluntarily recall red, yellow, and white onions imported from the State of Chihuahua, Mexico, with import dates from July 1, 2021 through August 27, 2021. Descriptors of these onion types include, but are not limited to, jumbo, colossal, medium, and sweet onions.

Epidemiological data collected by investigators from the CDC and state and local partners identified 20 illness clusters at restaurants where onions were served. Information from these clusters shows that many ill people ate raw onions. Investigators worked to identify a common food item eaten by all of the sick people in an effort to identify the source of the outbreak.

State officials collected food items from some of the restaurants where sick people ate. The outbreak strain of S. Oranienburg was found in a sample taken from a takeout condiment cup containing cilantro and lime. The sick person reported that the condiment container also contained onions, but none were left in the cup when it was tested. Because multiple food items were present in the container and in the sample that was tested, it is not possible to know which food item was contaminated.

Foodservice locations have also been associated with the illness subclusters being investigated in this outbreak. The investigation is ongoing and aims to determine the source of contamination and if additional products or firms are linked to illness. FDA is working to determine if these onions were available to consumers through grocery stores. Additional information will be provided as it becomes available.