The FDA has confirmed 11 patients in a new Listeria monocytogenes outbreak under active investigation, with the source of the pathogen still unidentified.

The patient count climbed from 10 to 11 in the past week, according to the agency's outbreak tracker. The FDA has not released patient ages or states of residence, consistent with standard early-stage practice. Traceback, onsite inspections, and sample collection are underway, though the agency is not publicly identifying what foods or facilities are under review.

The outbreak was first reported July 22, making it the longest-running Listeria investigation on the FDA's current active list.

What products are operators pulling right now?

Sierra Nevada Graziers has recalled every variety of its grass-fed raw milk cheese after 13 people across eight states contracted E. coli O26:H11.

Eight patients have required hospitalization. Three developed hemolytic uremic syndrome, a complication that can cause kidney failure, brain damage, and death. More than half of the patients are children younger than 5.

All nine patients interviewed reported eating the cheese in the week before becoming ill.

The recalled cheeses were distributed nationwide. Retail packages carry 8-ounce or 16-ounce formats; food service operators and wholesalers received 5-pound loaves. Varieties include:

• Medium cheddar
• Sharp cheddar
• Jalapeño jack
• Monterey jack

Is this the company's first recall?

No. In August 2025, California's State Veterinarian ordered a statewide recall and quarantine of Sierra Nevada's Bella Capra raw goat milk cheddar after the California Department of Food and Agriculture testing found Listeria monocytogenes in the product.

The new E. coli outbreak marks the second contamination event tied to the producer in roughly 12 months.

What other outbreaks is the FDA tracking?

The agency is monitoring 15 additional outbreak investigations. Three posted patient count increases over the past week:

• E. coli O157:H7: 38 patients, up from 25. Source unknown. First reported Sept. 23. Sample collection initiated.
• Listeria monocytogenes: 44 patients, up from 40. Source unknown. First reported Sept. 23. Traceback initiated.
• Listeria: 11 patients, up from 10. First reported July 22. Traceback, onsite inspections, and sample collection underway.

The FDA is not releasing patient ages, states of residence, or specific foods under traceback for any of the three.

What is the operator exposure?

Food service operators carrying Sierra Nevada Graziers raw milk cheese in 5-pound loaves face immediate inventory removal and potential menu disruption.

Distribution was nationwide, meaning affected product could sit in cold storage at restaurants, hotels, and catering operations across all 50 states.

Operators should pull all varieties of the recalled cheese, verify supplier records, and confirm recall coverage with their distributors.

With three of the most recently expanded outbreak investigations showing no identified source and the FDA conducting onsite inspections, additional recall notices are likely as traceback narrows.