The FDA has confirmed 32 Salmonella Bovismorbificans patients across six states as of Oct. 7, with three hospitalizations and no deaths, in an outbreak traced to a contaminated lot of broccoli sprouting seeds that the agency has refused to link to a named supplier.

Illness onset dates run from July 7 to Sept. 3, with the most recent patient falling ill on Sept. 3. Confirmed cases span Idaho, Minnesota, Montana, Oregon, Utah and Washington.

Interview data points squarely at sprouts. Of 27 people interviewed as of Sept. 24, 26 reported eating sprouts or microgreens. Twenty-two specifically reported eating broccoli sprouts, and one reported eating a microgreen mix containing broccoli microgreens.

What did traceback testing find?

Washington state officials collected and tested samples of Evergreen Fresh Sprouts-brand broccoli sprouts from a local grocery store and a sick person's home. Both samples carried the same Salmonella strain sickening patients.

The FDA then tested seeds from the supplier identified in its investigation. The seed sample tested positive, and whole genome sequencing matched the Salmonella Bovismorbificans strain behind the outbreak.

"As a result, the seed supplier conducted a recall of the implicated seed lot and contacted their customers," the FDA said in its outbreak update. The agency has not named that supplier, saying only the implicated sprouts were "grown from a contaminated seed lot."

Which products have been recalled?

Two retailers of the seeds have pulled product tied to supplier lot #W4105:

• EAK Distribution, Casper, WY — recalled Home Grown brand green sprouting broccoli seeds on Oct. 2 after being notified of the seed supplier's recall of lot #W4105.
• Eden Brothers LLC, Arden, NC — recalled calabrese broccoli seeds on Oct. 7 in packets and 1-ounce and 1-pound sizes, covering Eden Brothers lots 1022067 and 1022068, both tied to supplier lot W4105.

The implicated seeds were distributed in Idaho, Montana and Washington, but the FDA says they may have traveled further through secondary distribution. The agency is still working through the supply chain to identify other companies that received seeds from the unnamed supplier.

How does this affect growers and foodservice buyers?

Sprout growers who purchased broccoli seed lots #W4105 through either distributor face both a product loss and a traceability exposure — sprouts grown from the contaminated seed reached retail shelves and consumers' homes under the Evergreen Fresh Sprouts brand.

The scope of the outbreak almost certainly exceeds the confirmed count. The CDC estimates that for every Salmonella patient identified, 29 infections go undetected because many people do not seek treatment and others are never tested. Applied to this outbreak, that ratio suggests the true case count could approach 1,000.

This outbreak is separate from a concurrent E. coli and Salmonella outbreak linked to alfalfa sprouts. The FDA also knows the seed supplier in that investigation but is not releasing the company's name.

The FDA's ongoing supply-chain review will determine whether additional seed buyers and sprout producers need to issue recalls tied to lot #W4105.