Three people are dead and three others were hospitalized after drinking milkshakes sold at a Washington restaurant that were contaminated with listeria bacteria, health officials said.
Investigators linked the outbreak back to Frugals – a restaurant in Tacoma, Washington, about 30 miles from Seattle – after two of the six people hospitalized said they drank the milkshakes before getting sick, the Washington State Department of Health said in a news release Friday.
Investigators collected samples from the ice cream machines, which they said were not cleaned correctly, and found the bacteria in the machines.
Investigators said the restaurant stopped using the machines on Aug. 8, but people can get sick up to 70 days after being contaminated with listeria, the health department said.
“Genetic fingerprinting of bacteria in the milkshakes shows it’s the same strain of listeria that hospitalized six people between Feb. 27 and July 22,” the health department said. “All six people had conditions that made their immune systems less able to fight [the] disease.”
What is listeria monocytogenes?
Listeria monocytogenes is a pathogenic bacteria found in moist environments, soil, water, decaying vegetation and animals. It can be transmitted when food is harvested, processed, prepared, packed, transported or stored in places that are already contaminated with the bacteria, according to the United States Food and Drug Administration.
People who eat food contaminated with listeria can develop listeriosis. People who are pregnant, adults aged 65 or older and people with weakened immune systems are most likely to get seriously sick, according to the CDC.
People who are pregnant usually feel tired, have muscle aches and have a fever. listeria can also cause pregnancy loss and premature birth, the health department said.
People who are not pregnant usually have symptoms including:
Loss of balance
Listeria can be treated with antibiotics, the health department said.
Listeria outbreak this month may be linked to ice cream recall
Earlier this month, the FDA announced a listeria outbreak potentially linked to Soft Serve On The Go ice cream cups made by Real Kosher Ice Cream of Brooklyn, New York, after two people felt ill after eating the ice cream.
"The Pennsylvania Department of Agriculture collected an unopened sample of Soft Serve On The Go from an ill person’s home. This sample was reported as positive for listeria monocytogenes," the FDA said.
Contributing: Kate Perez, USA TODAY
This article originally appeared on USA TODAY: Listeria outbreak: 3 dead from tainted milkshakes in Tacoma, Wash.