The Centers for Disease Control and Prevention this week warned distributors against selling hard-boiled eggs bought in bulk from a Georgia production plant that it said was the likely source of listeria contamination that had led to sicknesses in five states, including one death and four hospitalizations.

Officials with the federal Food and Drug Administration discovered the strain during a routine inspection in February at Almark Foods in Gainesville, Ga. The C.D.C. determined that the strain was the same one that caused three infections in 2017.

By this month, the strain had been found in at least five states — Florida, Maine, Pennsylvania, South Carolina and Texas — and in four more people, the C.D.C. said in a safety alert that it issued on Wednesday.