Listeria bacteria found in ice cream machines in Washington state linked to 3 deaths

Milkshakes made from machines found to contain Listeria bacteria and sold at a restaurant in Washington state have been linked to the deaths of three people, according to state health officials.

Investigators found Listeria bacteria in the ice cream machines at a Frugals restaurant in Tacoma, the Washington State Department of Health (WSDH) said. The bacteria was associated with what authorities called a “foodborne listeriosis outbreak,” which led to six hospitalizations. Three of those hospitalized later died, according to the WSDH.

Officials said the machines were not cleaned correctly.

Health department officials said the Frugals restaurant stopped using the machines on Aug. 8, but Listeria bacteria can sicken people up to 70 days later.

"Most people who eat food contaminated with Listeria will not get seriously sick, but people who are pregnant, aged 65 or older, and those with weakened immune systems should call their health care provider if they ate a Frugals’ Tacoma milkshake between May 29 and Aug. 7, 2023," Washington State Department Health officials said in a statement on Friday.

In a statement posted on Instagram, Frugals said they have been "working with PCHD to identify and contain the source of listeria after a test on a milkshake machine" in the Tacoma location "tested positive for the bacteria.

"Today, we were deeply saddened to learn the Washington State Department of Health is reporting six people were hospitalized with foodborne listeriosis and three people later died. We are heartbroken and deeply regret any harm our actions could have caused," the company's statement continued.

Frugals said in the statement they are having their milkshake machines sent to an "independent facility for thorough cleaning, sanitization and re-testing."

The company's statement continued: "[O]ut of an abundance of caution for our customers, we have also directed all milkshake machines in our other locations to be shut down and samples from these machines be sent out for similar testing. Although not required by PCHD, Frugals will also undergo enhanced cleaning, safety and sanitization procedures across all product categories and alt all store locations."

Frugals has not yet responded to ABC News' request for comment.

Listeria can be treated with antibiotics, according to health officials.

Listeria can cause severe illness "when the bacteria spread beyond the gut to other parts of the body" after a person consumes contaminated food, according to the CDC. Those who are pregnant, aged 65 or older, those with weakened immune systems and newborns are most likely to become seriously ill if exposed.

Those infected with listeria may experience "food poisoning symptoms" such as diarrhea, vomiting, or fever, per the CDC. Symptoms for severe illness may include headache, stiff neck, confusion, loss of balance, seizures and flu-like symptoms such as muscle aches and fatigue.

As for the case in Washington, genetic fingerprinting of bacteria in the milkshakes showed it was the same strain of Listeria that hospitalized six people between Feb. 27 and July 22, according to the WSDH.

The six people had weakened immune systems, making it harder to fight the disease, officials said.