A cluster of E. coli infections affecting residents in Washington and Oregon has been traced to artisanal cheese produced by Twin Sisters Creamery, a Ferndale-based specialty dairy operation, prompting health officials to issue urgent warnings about consuming specific products that may still be stored in consumers’ homes.
The Snohomish County Health Department announced Thursday that at least 10 confirmed cases of Shiga Toxin-Producing E. coli infection have been linked to the creamery’s products, with nine cases in Washington and one in Oregon. The latest Washington case connected to the outbreak was identified on 6 November, though all infected individuals reported illness onsets before the company initiated a product recall on 24 October 2025.
The Washington State Department of Health is coordinating with local health jurisdictions, the Oregon Health Authority, and federal public health agencies to investigate the outbreak’s scope and prevent additional infections. The multi-jurisdictional investigation reflects the interstate distribution networks through which specialty cheese products reach consumers, complicating efforts to notify all potentially affected purchasers.
Health officials are urging the public to immediately discard four specific Twin Sisters Creamery cheese varieties: Whatcom Blue, Farmhouse, Peppercorn, and Mustard Seed. The advisory applies to all packages of these products regardless of purchase date or location, as investigators work to determine which specific production batches were contaminated.
“Check refrigerators or freezers for the brand and variety of cheese and throw them away,” Washington State Department of Health officials stated, emphasising the importance of consumer action in preventing additional illnesses.
The recall presents particular challenges because of incomplete batch identification information on some packages. Health officials advise consumers to discard any Twin Sisters Creamery cheese that lacks a “Made On” date or Batch Code on the packaging. Furthermore, due to difficulties in identifying batch information on remaining packages, officials recommend discarding all Twin Sisters cheeses as a precautionary measure.
The Department of Health indicated that additional products may be recalled or identified as possible sources of infection as the investigation continues, suggesting the full scope of contamination remains under assessment.
The outbreak involves Shiga Toxin-Producing E. coli, a particularly dangerous pathogen category that can cause severe illness far exceeding typical food poisoning symptoms. Whilst E. coli bacteria normally inhabit human and animal intestines harmlessly, STEC strains produce toxins that can damage the lining of the small intestine and, in severe cases, lead to kidney failure through a condition called hemolytic uremic syndrome.
The connection between STEC and aged raw milk cheese reflects well-documented food safety risks associated with unpasteurised dairy products. Raw milk can harbour pathogenic bacteria if dairy cattle carry E. coli in their intestines, with the bacteria potentially contaminating milk during the milking process. Whilst proper cheese aging under controlled conditions can reduce pathogen levels through acidification and competitive exclusion by beneficial bacteria, failures in temperature control, pH management, or sanitation can allow dangerous bacteria to persist or multiply.
Artisanal cheese producers like Twin Sisters Creamery often use raw milk to develop complex flavour profiles that pasteurisation would eliminate. The aging process, which can extend from weeks to months depending on cheese variety, theoretically provides time for natural antimicrobial processes to reduce pathogens. However, this approach requires meticulous attention to production conditions, milk quality, and environmental controls to ensure safety.
The timing detail that all illness onsets occurred before the 24 October recall date suggests contaminated products have been removed from retail distribution channels for several weeks, reducing the risk of new purchases. However, aged cheeses have extended shelf lives and consumers often store specialty cheeses for weeks or months, creating scenarios where contaminated products purchased before the recall remain in refrigerators or freezers awaiting consumption.
Health officials outlined severe STEC symptoms requiring immediate medical attention: diarrhoea accompanied by fever higher than 102°F, diarrhoea persisting more than three days without improvement, bloody diarrhoea, or vomiting so severe that fluids cannot be retained. These symptoms distinguish STEC infections from milder foodborne illnesses and signal potential progression toward life-threatening complications.
The bloody diarrhoea characteristic of STEC infections results from toxin damage to intestinal blood vessels, whilst high fever indicates systemic inflammatory response to infection. The inability to retain fluids creates dehydration risks that compound illness severity, particularly dangerous for young children, elderly adults, and individuals with compromised immune systems who face highest risk for hemolytic uremic syndrome.
