The US Food and Drug Administration on Tuesday escalated Starfish Seafood's smoked salmon recall to Class I, its most serious tier, after Listeria monocytogenes was confirmed in additional production lots. The expanded recall now covers distribution beyond New Jersey, Pennsylvania, and Ohio.

A Class I designation indicates a reasonable probability that consumption will cause serious health consequences or death. The action followed a second recall notice issued earlier this month, when contaminated smoked salmon reached shoppers in three states.

The Centers for Disease Control and Prevention confirmed it was investigating illnesses linked to the product. Listeria infection poses the greatest danger to pregnant women, newborns, older adults, and people with weakened immune systems. Symptoms can appear up to 70 days after exposure, complicating case counts.

Starfish Seafood urged consumers to discard affected packages or return them for a refund and instructed retailers to pull remaining stock from shelves. The company halted production at the implicated facility while working with regulators to identify the contamination source.

Ready-to-eat smoked fish remains a recurring source of Listeria outbreaks because the product is not cooked before consumption, allowing the bacterium to survive refrigeration.