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.
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.
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 no 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.
