2023 Outbreak of Foodborne Listeriosis Associated with Consumption of Restaurant Milkshakes

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Last updated: 8/18/2023


Between February 27 and July 22, 2023, six Washington residents (five from Pierce County and one from Thurston County) developed severe illness due to infection with Listeria bacteria (listeriosis). All six people had conditions which made their immune systems less able to fight disease. Three of the individuals died. Genetic fingerprinting (whole genome sequencing) of the bacteria indicated that the same food was likely responsible for making all six people sick.

Two of the people infected with listeriosis reported consuming milkshakes from Frugals restaurant at 10727 Pacific Ave. S., Tacoma, WA, 98444 prior to becoming sick. Because milkshakes and ice cream have caused listeria outbreaks in the past, the Tacoma-Pierce County Health Department collected milkshake samples from the restaurant on August 8, 2023. On August 18, 2023, all flavors of the milkshakes were found to be contaminated with the same strain of Listeria that caused the outbreak.

The restaurant discontinued use of its two milkshake machines on August 8. The milkshake machines will be kept out of service until the Tacoma-Pierce County Health Department determines they are free of Listeria contamination and no longer pose a danger to the public.

Advice to Consumers

Most people who consume food contaminated with Listeria will not experience a serious illness. Persons who are high risk for invasive listeriosis infection (people aged 65 years or older, people with compromised immune systems and people who are pregnant) should contact their health care provider if they consumed milkshakes of any flavor from Frugals-Tacoma between May 29 and August 7, 2023 and develop any of the symptoms listed below:

  • Fever
  • Flu-like symptoms, such as muscle aches and fatigue
  • Headache
  • Stiff Neck
  • Confusion
  • Loss of balance
  • Seizures

Summary of Illnesses

Description of Ill Persons

Number Ill









Age range

40, 60s and 70s (years of age)






Listeriosis Case Counts

County of Residence

Total Cases





Public Health Actions

The state Department of Health is working with Pierce and Thurston County local health jurisdictions to gather information from interviews with patients and their families to help identify any common exposures.

About Listeria

Listeria bacteria are found in the environment and can spread from contaminated food to surfaces. Listeria can grow on foods kept in the refrigerator for several days. The bacteria are easily killed by heating food to a high temperature (165°F).

Although healthy, non-pregnant individuals may suffer only short-term symptoms such as fever, muscle aches, nausea, abdominal pain and diarrhea, Listeria monocytogenes is especially harmful to some people:

  • For people who are 65 years or older, Listeria infection often results in hospitalization and sometimes death.
  • For people who have a weakened immune system ((have health problems or take medicines that lower the body’s ability to fight germs and sickness), Listeria infection often results in hospitalization and sometimes death.
  • For people who are pregnant, Listeria infection can cause pregnancy loss, premature birth, or a life-threatening infection in the newborn.

Symptoms usually start within 2 weeks after eating food contaminated with Listeria monocytogenes but may start as early as the same day or as late as 10 weeks after exposure.

  • People who are not pregnant usually have fever, muscle aches, and tiredness. They may also get a headache, stiff neck, confusion, loss of balance, or seizures.
  • Pregnant people usually have fever, muscle aches, and tiredness.

How You Can Prevent Listeriosis

People at high risk for listeriosis, including people who are pregnant, people who are 65 years or older, and those with weakened immune systems, can reduce their risk of getting listeriosis by choosing safer foods. 

Don't Eat: Unpasteurized soft cheese, such as queso fresco and brie or unheated cheeses sliced at a deli.

Choose These Instead

  • Pasteurized soft cheeses heated to an internal temperature of 165°F or until steaming hot.
  • Deli-sliced cheeses heated to 165°F or until steaming hot.
  • Hard cheeses, such as cheddar and parmesan.
  • Cottage cheese, cream cheese, string cheese, and feta.

Don't Eat: Unheated deli meat, cold cuts, hot dogs, and fermented or dry sausages.

Choose These Instead

  • Deli meat, cold cuts, hot dogs, and fermented or dry sausages reheated to 165°F or until steaming hot.

Don't Eat: Premade deli salads, such as coleslaw and potato, tuna, or chicken salad.

Choose These Instead

  • Homemade deli salads.

Don't Eat: Refrigerated pâté or meat spreads.

Choose These Instead

  • Pâté or meat spreads in sealed, airtight containers that don’t need to be kept refrigerated before opening.

Don't Eat: Refrigerated smoked fish.

Choose These Instead

  • Smoked fish in sealed, airtight packages or containers that don’t need to be kept refrigerated before opening.
  • Smoked fish cooked in a casserole or other cooked dishes.

Don't Eat: Raw or lightly cooked sprouts.

Choose These Instead

  • Sprouts cooked until steaming hot.

Don't Eat: Cut melon left out for more than 2 hours (1 hour if it’s exposed to temperatures hotter than 90°F, such as a picnic or hot car) or cut melon that's been in the refrigerator for more than a week. 

Choose These Instead

  • Melon that has just been cut.

Don't Eat: Raw (unpasteurized) milk, yogurt, and ice cream.

Choose These Instead

  • Pasteurized milk, yogurt, and ice cream.

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