Two major food recalls in recent weeks have heightened concern about listeria contamination.
Blue Bell Creameries has recalled more than 25 of its ice cream products in the last month after several people got sick and three deaths were reported. And this week, Sabra announced a recall of its classic hummus because of possible listeria contamination.
Listeria is a bacteria which can spread via contaminated food, causing an infection known as Listeriosis.
Symptoms may include fever, muscle aches, nausea and diarrhea. Most people are able to fight off the illness, but in some cases it can be deadly. Listeriosis poses the greatest risk to older adults, pregnant women, newborns and people with weakened immune systems.
"It can get out of the intestine and into the blood stream m and can cause encephalitis, and if a woman is pregnant it can precipitate a miscarriage," Dr. William Schaffner of Vanderbilt University Medical Center told CBS News.
Health officials say three people who ate tainted ice cream from Blue Bell Creameries later died. The FDA says is has no reports of illnesses linked to the Sabra hummus recall.
Unlike most other forms of foodborne bacteria, listeria can grow even in cold temperatures. That means a contaminated product can get even more dangerous as it sits in the refrigerator.
"The bacteria can multiply so it becomes more likely to make you sick. So it's very important that you check your refrigerator that you don't have any of these products, and discard them," Schaffner said.
A person who eats food contaminated with listeria can develop symptoms anywhere from a few days to a few weeks or months later. The illness is usually treated with antibiotics.
The FDA has more information on its website, including a complete list of products affected by the recalls: