The Food and Drug Administration (FDA) has issued a new warning about thousands of recalled eggs sold at Costco (COST) stores due to potential contamination with salmonella, a bacterium that can cause serious infections.

The Food and Drug Administration has escalated its recent recall of eggs sold at Costco to its highest alert level, citing possible salmonella exposure. In November, Costco recalled nearly 260,000 eggs sold under the Kirkland Signature brand in 25 stores nationwide.

Nearly a month after a five-state recall of eggs sold at Costco, the FDA now says consumption of the recalled eggs could "cause serious adverse health consequences or death."