Outbreak Investigation Updates by Date
Posted February 27, 2019 at 3:45 PM ET
This outbreak appears to be over, but recalled tahini products have a long shelf life and may still be in people’s homes. Consumers unaware of the recall could continue to eat these products and potentially get sick. Visit the FDA websiteExternal for a full list of recalled products.
CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA) are investigating a multistate outbreak of Salmonella Concord infections.
Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. PulseNet is the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC. DNA fingerprinting is performed on Salmonella bacteria isolated from ill people by using techniques called pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). CDC PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks. WGS gives a more detailed DNA fingerprint than PFGE. WGS performed on bacteria isolated from ill people showed that they were closely relatedly genetically. This means that people in this outbreak are more likely to share a common source of infection.
As of November 28, 2018, five people infected with the outbreak strain of Salmonella Concord have been reported from three states. A list of the states and the number of cases in each can be found on the Map of Reported Cases page.
Illnesses started on dates ranging from June 16, 2018 to October 18, 2018. Ill people range in age from 17 to 52 years, with a median age of 30. Sixty percent of ill people are male. Of five people with information available, no hospitalizations or deaths have been reported.
Illnesses might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 4 weeks. Please see the Timeline for Reporting Cases of Salmonella Infection for more details.
Whole genome sequencing analysis did not predict any antibiotic resistance in Salmonella bacteria isolated from three ill people. Testing of clinical isolates using standard antibiotic susceptibility testing methods by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory is currently underway.
Investigation of the Outbreak
Epidemiologic and laboratory evidence indicates that tahini products from Achdut Ltd. are the likely source of this outbreak.
In interviews, ill people answered questions about the foods they ate and other exposures in the week before they became ill. All five ill people were interviewed and reported eating tahini or hummus made with tahini. Three ill people ate tahini or hummus made with tahini in Hawaii and New York. The other two ill people traveled to other countries where they ate tahini or hummus made with tahini.
FDA identified Salmonella Concord in a sample of tahini collected at the point of import. The tahini was Baron’s brand manufactured by Achdut Ltd. Whole genome sequencing results showed that the Salmonella strain identified in imported tahini was closely related genetically to the Salmonella strain identified in ill people. These results provide more evidence that people in this outbreak got sick from eating tahini products from Achdut Ltd.
On November 27, 2018, Achdut Ltd. recalled tahini products because they might be contaminated with Salmonella. The FDA website has a list of the tahini productsExternal that were recalled. Consumers who have any recalled tahini products in their homes should not eat them. Return them to the store for a refund or throw them away. Restaurants and retailers should not serve or sell recalled tahini products or products made with them, such as hummus.
This investigation is ongoing, and CDC will provide updates when more information is available.