In the summer of 2015, some 150 people were stricken with Salmonella at uppity Fig and Olive restaurants in Washington, D.C. and Los Angeles.

The salmonella outbreak shut down the City Center, DC location for six days in Sept. 2015. The Food and Drug Administration and local health authorities never definitively determined the exact source of the salmonella, but truffle mushroom croquettes were a common denominator among Fig & Olive diners who got sick. Components of the dish were pre-prepared at a Long Island City commissary that supplied Fig & Olive’s restaurants around the country with already-made sauces, dressings, and more, and has since been closed.

Six months and a round of layoffs later, one former mid-level executive told Jessica Sidman of Washington City Paper, “They’re an image conscious-first company. They don’t care about the guest. They care about their image, and they care about the bottom line … It’s just not a good company.”

The U.S. Centers for Disease Control has now weighed in on the source of the Salmonella – without naming the restaurant.

During July–September 2015, a total of 159 patrons reported gastrointestinal illness after eating at a single District of Columbia restaurant. Forty-one persons (40 restaurant patrons and one employee) were infected with an indistinguishable Salmonella Enteritidis strain on the basis of pulsed-field gel electrophoresis (XbaI pattern JEGX01.0008). Results from a case-control study using restaurant patron data identified a novel food vehicle, truffle oil, as the likely source of Salmonella Enteritidis infection in this outbreak. Approximately 89% of case-patients reported eating truffle oil–containing items, compared with 57% of patrons who did not report gastrointestinal illness (p<0.001).

Public health officials and consumers should be aware that truffle oil has been implicated as the likely source of a Salmonella Enteritidis outbreak and could possibly harbor this pathogen. Timely engagement of the public, health care providers, and local and federal public health officials, is particularly critical for early recognition of outbreaks involving common foodborne pathogens, such as Salmonella Enteritidis.