The CDC issued a food safety alert yesterday over an outbreak that has led to one death and four hospitalizations.

The cause of a deadly Listeria outbreak was identified by the CDC yesterday in a food safety alert. The agency is concerned that packaged hard-boiled eggs from Almark Foods out of Gainesville, Georgia are contaminated with Listeria, which has led to seven reported cases across five states. Reported cases—including one death and four hospitalizations—have been made in Florida, Texas, Maine, Pennsylvania and South Carolina.

Although these products have not yet been recalled, the CDC urges anyone to abstain from selling, serving or using these products in any way. The CDC is urging retailers and food service operators alike to not use any hard-boiled eggs that were produced by Almark Foods—regardless of their use-by date. They also encourage washing and sanitizing any surfaces that may have come in contact with the eggs or their packaging.

Since this food safety alert does not include Almark Foods hard-boiled eggs sold directly to the consumer, the CDC advises those who have a higher risk for listeria—pregnant women, adults 65 and older and those with compromised immune systems—to throw away any hard-boiled eggs purchased in-store or products made with these hard-boiled eggs (like egg salad).

Foods contaminated with Listeria often do not smell or look spoiled, but can still lead to life-threatening infections and serious symptoms including nausea, vomiting, fever, muscle aches, neck stiffness and severe headaches. Anyone who is experiencing these symptoms should contact a healthcare professional immediately.