WORCESTER, Mass. — A local expert is asking people to be vigilant with a listeria outbreak impacting people across the country.

Deli meat company "Boar's Head" is recalling an additional 7,000,000 pounds of ready-to-eat products after a deadly listeria outbreak. The contamination was traced back to one of the company's processing plants in Virginia.

A listeria infection is a foodborne bacteria illness. The Centers for Disease Control and Prevention says the bacteria has led to dozens of hospitalizations and two deaths. The specific products which caused them is unclear.

Infectious disease expert Mireya Wessolosski from UMass Memorial Health says what makes listeria a challenge is how difficult it is to detect it. 

"It requires a level of suspicion from the clinician or doctors to the suspect on that," Wessolosski said. "So we tend to make a differential diagnosis when a patient comes with that type of illnesses and say, 'Don't forget about listeria,' which can present like any other kind of flu-like symptoms or meningitis."

Listeria infections typically cause fever, muscle aches and tiredness. It can also cause a stiff neck, confusion, loss of balance and convulsions. 

Wessolossky says if you have any food you're suspicious or nervous about, don't take any chances and throw it out.