A Salmonella Braenderup outbreak at the Green Mill restaurant in Bloomington, Minnesota sickened at least seven people, according to a report by the Minnesota Department of Health. This outbreak was discovered on April 19, 2019. Five of those cases are lab-confirmed.
The investigation began when officials found that two clinical Salmonella Braenderup isolates submitted to the MDH Public Health Laboratory through routine surveillance had indistinguishable pulsed-field gel electrophoresis patterns. Interviews with those two patients found that they had eaten food at the Green Mill restaurant in Bloomington, Minnesota before they got sick. The City of Bloomington Environmental health Division started an investigation.
Cases were defined as people who tested positive for Salmonella Braenderup with PFGE pattern BR134, or a Green Mill-Bloomington patron who developed diarrhea that lasted for three days, after eating food from that facility.
MDH interviewed 89 patrons and 18 catered training event attendees. They found them through information about catered events and receipts from the restaurant. Seven cases were identified. Two of the patrons reported illness but didn’t meet the case definition and were excluded. Dates where the customers ate at the restaurant were March 22, April 5, April 8, April 9, and April 10, 2019. Four of the patients had 2 to 3 meal dates.
Illness onset dates ranged from March 29 to April 16, 2019. The patient age range was from 6 to 65 years. Four of the patients visited a health care provider, but none were hospitalized.
You can contact Minneapolis food safety attorney Fred Pritzker for help by calling 612-338-0202 or 1-888-377-8900.
Three of the lab-confirmed cases attended the same training event that was catered by the Green Mill restaurant on April 8, 9, and 10, 2019. All of the other cases were sit-down customers or ordered take-out from the venue.
The foods that are suspect in this outbreak are tomatoes and romaine lettuce; they are statistically associated with the illnesses. In addition, two employees who did not report any symptoms teated positive for Salmonella Braenderup that matched patient isolates using PFGE and whole genome sequencing.
Investigators noted several issues at the restaurant. The produce wash was plumbed to the 3-compartment sink. The paper towel dispenser on the cook line was empty. An employee touched pizza with bare hands. And an employee rinsed a pizza cutter in the hand sink. Finally, the pressure gauge was not working on the dishwasher.
The conclusion reached by MDH was that tomato and romaine lettuce were associated with the illnesses. Food workers may have been the source of contamination, but other sources could not be ruled out.
