2025 Outbreak of Shiga toxin-Producing E. coli (STEC) Infections Linked to Twin Sisters Creamery Aged Raw Milk Cheese

Last Updated: October 24, 2025

Washington State Department of Health is working with local, state, Oregon Health Authority and federal public health partners to investigate Shiga Toxin-Producing E. coli (STEC) infections linked to consumption of aged, raw milk cheese. Two Washington residents and one Oregon resident have developed STEC infections caused by E. coli O103. Molecular fingerprinting of the bacteria from the three cases is extremely similar, suggesting a common source is the cause of the infections.

One individual is a child (<5 years of age) and two individuals are adults. Illnesses occurred between September 5 and September 16, 2025.

The Oregon case reported consuming Twin Sisters Creamery Farmhouse cheese prior to onset of symptoms. This cheese is made from raw, unpasteurized milk. This cheese is aged at least 60 days, as required by law, to reduce potential pathogens.  An opened, leftover Twin Sisters Creamery Farmhouse cheese sample tested positive for E. coli O103 and the molecular fingerprinting of this organism is very similar to fingerprints from the case-organisms. 
A second, unopened Twin Sisters Creamery cheese collected from a retail location by the Washington State Department of Agriculture (WSDA) also tested positive for STEC. Additional unopened samples of cheese from multiple retail locations were collected for testing with results pending.

This investigation is ongoing. Twin Sisters Creamery is cooperating with the investigation.

In Washington

Quick Facts

  • Cases: 2
  • Hospitalizations: 1
  • Status: Ongoing
  • Recall: Yes

Recalled Food

All sizes of Whatcom Blue, Farmhouse, Peppercorn and Mustard Seed varieties of aged cheese from Twin Sisters Creamery produced on or after 5/27/2025 are being recalled.

  • #450 Made on 5/27/2025 - Batch Code 250527B Whatcom Blue
  • #452 Made on 6/10/2025 - Batch Code 250610B Whatcom Blue
  • #454 Made on 6/18/2025 - Batch Code 250618B Whatcom Blue
  • #455 Made on 6/24/2025 - Batch Code 250625B Whatcom Blue
  • #451 Made on 6/03/2025 - Batch Code 250603F Farmhouse
  • #453 Made on 6/16/2025 - Batch Code 250616B Farmhouse
  • #451 Made on 6/03/2025 - Batch Code 250603P Peppercorn
  • #453 Made on 6/16/2025 - Batch Code 250616 Mustard Seed

Some cheese products were repackaged by grocery stores and markets, so the original label may not be present. In these instances, the grocery store/market label should say the brand of cheese.

Local, state, and federal partners continue to investigate the source of illness for outbreak-related cases and additional products may be recalled or identified as a possible source of infection in the future.

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Twin Sisters Creamery Whatcom Blue Cheese
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Twin Sisters Creamery Farmhouse Cheese
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Twin Sisters Creamery Mustard Seed Cheese
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Twin Sisters Creamery Peppercorn Cheese

About E coli

E. coli are bacteria that normally live in the intestines of humans and animals. Although most strains are harmless, some can cause illness by making a toxin called Shiga toxin. The bacteria that make these toxins are called “Shiga toxin-producing” E. coli, or STEC for short.

People usually get STEC infection by eating contaminated foods or drinks that have not been thoroughly cooked or pasteurized (heat treated). Symptoms may include diarrhea, stomach cramps, or blood in the stool. Some infected people have symptoms at all.

To prevent E. coli infection

  • Do not eat raw beef or raw or under-cooked hamburger or other ground meat products.
  • Keep ready-to-eat foods (i.e., raw vegetables) away from raw meat.
  • Drink only pasteurized (not raw) milk, milk products and fruit juices.

More Resources


To report a suspected foodborne illness or file a complaint about unsafe food handling practices at an establishment in Washington, use the Foodborne Illness Notification System (FINS).

Cases by County of Residence

County Cases
Whatcom 2
Total Cases 2

Advice to Consumers

  • Do not eat any recalled Whatcom Blue, Farmhouse, Peppercorn, and Mustard Seed varieties of Twin Sisters Creamery cheese. Check your refrigerators or freezers for this brand and variety of cheese and throw them away.
    • If there is no “Made On” date or Batch Code on the cheese packaging, please throw them away.
  • Wash items and surfaces that may have touched the cheese using hot soapy water or a dishwasher.
  • Contact your healthcare provider right away if you have any of these severe STEC E. coli symptoms:
    • Diarrhea and a fever higher than 102°F
    • Diarrhea for more than 3 days that is not improving.
    • Bloody diarrhea
    • So much vomiting that you cannot keep liquids down.

Advice to Retailers

  • Check to see if you received Twin Sisters Creamery Cheese, Whatcom Blue, Farmhouse, Peppercorn, and Mustard Seed varieties produced since 5/27/2025.
    • If you are unsure if you received the recalled product, please contact your supplier.
  • If you received the recalled lots:
    • Do not sell or serve the recalled cheese.
    • If possible, notify your customers who may have purchased the recalled cheese or items in-store that include the recalled cheese
    • Place signs at locations where the cheese were sold to help notify consumers
  • Wash and sanitize items and surfaces that may have come in contact with Twin Sisters Creamery brand cheese.

Outbreak-Specific Resources