Truffle oil linked to Salmonella outbreak at a restaurant
What it found
In 2015, 159 people in 11 states and Washington DC got stomach illness after eating at one restaurant.
A case-control study pointed to truffle oil as the likely source of Salmonella Enteritidis.
What they found
Studies in people
Illness and symptoms
Among 153 sick people with symptom information, 143 had diarrhea, 128 had abdominal cramps, 105 had chills, 103 had headache, 100 had nausea, and 82 had fever.
Truffle oil link
Six food items were significantly linked to illness, three of which contained truffle oil. When all truffle oil items were combined, 89% of sick people reported eating one compared with 57% of people who did not get sick.
Lab confirmation
All 41 people who gave stool samples had the same outbreak strain of Salmonella Enteritidis. One restaurant employee was also confirmed to have the infection.
Animal and lab studies
Food testing
Truffle fries screened positive for Salmonella by PCR, but the bacteria could not be grown in confirmatory testing. All other food and environmental samples were negative for Salmonella.
Other findings
Traceback investigation
The New York commissary that supplied truffle oil and other items had stopped operating before it could be tested. Records for the truffle oil shipped during August 1 to September 15 showed no significant findings.
What the authors conclude
“Despite these limitations, the epidemiologic evidence strongly suggested that truffle oil was the likely source of the outbreak.”
Also in their conclusions
- They say the epidemiologic evidence strongly suggested that truffle oil was the likely source of the outbreak.
- They advise that 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.
- They note that 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.
How it was done
The authors investigated because a person reported gastrointestinal illness after eating at a restaurant, and more cases were soon reported.
They interviewed 254 patrons who ate at the restaurant between July 1 and September 10, 2015. They compared 159 people who got sick with 95 who did not, and tested food and environmental samples for Salmonella.
What it can’t tell you
- The exact source of contamination was not confirmed because food and environmental samples were collected after the restaurant had begun disposing of food items and the commissary had closed.
- The truffle oil sampled on September 14 was unlikely to have been consumed by sick people, because the latest meal date was September 9.
- Because Salmonella could not be grown from food samples, it could not be established whether the PCR-detected Salmonella in the truffle fries led to actual illness or matched the outbreak strain.
The paper
- Title
- Investigation of Salmonella Enteritidis Outbreak Associated with Truffle Oil - District of Columbia, 2015
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Kuramoto-Crawford SJ, McGee S, Li K, et al (2017). Investigation of Salmonella Enteritidis Outbreak Associated with Truffle Oil - District of Columbia, 2015. MMWR. Morbidity and mortality weekly report. doi:10.15585/mmwr.mm6610a4Free full textPubMed 28301453DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error