Here's what to know about recalled Boar's Head deli meats linked to a deadly listeria outbreak

abcnews.go.com:

A deadly food poisoning outbreak has led to the recall of more than 7 million pounds of popular Boar’s Head deli meats made at a plant in Virginia

A deadly food poisoning outbreak has led to the recall of more than 7 million pounds of popular Boar's Head deli meats made at a plant in Virginia.

U.S. health officials are investigating the outbreak of the bacteria listeria that began in May. Two people have died and nearly three dozen were hospitalized in 13 states.

Listeria poisoning is caused by a particularly resilient type of bacteria that can survive and grow even during refrigeration, according to the Centers for Disease Control and Prevention.

Here’s what you need to know:

Listeria bacteria thrive in moist environments, including soil and water and decaying vegetation and are carried by some animals. The hardy germs are typically spread when food is harvested, processed, transported or stored in places that are contaminated with the bacteria. When the bacteria get into a food processing plant, they can be tough to eradicate.

Many of the people in the outbreak reported eating meats sliced at grocery store deli counters. During the investigation, listeria was detected in an unopened loaf of Boar's Head liverwurst at a Maryland store; the Agriculture Department said further testing showed the same strain was causing illnesses in people.

People are sickened with listeria poisoning when they eat foods contaminated with the bacteria. Symptoms can be mild and include fever, muscle aches, nausea, vomiting and diarrhea. More serious illness can include headache, stiff neck, confusion, loss of balance and convulsions.

Listeria poisoning is tricky, because symptoms can start quickly, within a few hours or days after eating