CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA) are collecting different types of data to investigate a multistate outbreak of Salmonella Thompson infections.

Epidemiologic and traceback data show that onions processed at Gills Onions may be contaminated with Salmonella and may be making people sick.

As of October 24, 2023, a total of 73 people infected with the outbreak strain of Salmonella have been reported from 22 states. Illnesses started on dates ranging from August 2, 2023, to September 25, 2023. Of the 65 people with information available, 15 (23%) have been hospitalized. No deaths have been reported.

States with numbers of ill:

Arizona 1, California 17, Colorado 1, Georgia 1, Iowa 1, Idaho 1, Illinois 4, Indiana 2, Kentucky 1, Massachusetts 1, Michigan 6, Montana 2, North Dakota 2, New York 1, Ohio 3, Oregon 3, Tennessee 1, Texas 1, Utah 17, Virginia 3, Wisconsin 3, Wyoming 1.

The true number of sick people in this outbreak is likely much higher than the number reported, and the outbreak may not be limited to the states with known illnesses. This is because many people recover without medical care and are not tested for Salmonella. In addition, recent illnesses may not yet be reported as it usually takes 3 to 4 weeks to determine if a sick person is part of an outbreak.

State and local public health officials are interviewing people about the foods they ate in the week before they got sick. Of 19 people with information available, 14 (74%) reported eating onions or being served diced onions. Of these 14 people, 6 people reside in long-term care facilities. Investigators identified a sub-cluster of three people who reside in the same long-term care facility. Investigating a subcluster can sometimes help identify a food item eaten by all the sick people that could be the source of the outbreak.

Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. CDC PulseNet manages a national database of DNA fingerprints of bacteria that cause foodborne illnesses. DNA fingerprinting is performed on bacteria using a method called whole genome sequencing (WGS). WGS showed that bacteria from sick people’s samples are closely related genetically. This suggests that people in this outbreak got sick from the same food.

FDA conducted a traceback investigation and determined that onions processed at Gills Onions were available at points of service where people ate prior to becoming ill. Meal records from the long-term care facilities showed that people were served diced onions from Gills Onions.

On October 24, 2023, Gills Onions recalled fresh diced onion products. CDC is advising people to check their freezers and to not eat any recalled diced onions. Businesses should not sell or serve recalled Gill’s Onions products or use recalled onion products in other foods.