Ten people have been put into the hospital by an outbreak of Listeria traced to Blue Bell brand ice cream, and three have died. The Centers for Disease Control and Prevention says two Blue Bell factories may have been spreading Listeria for five years.
Here are five things you need to know about Listeria:
It likes the cold
Listeria bacteria are especially sneaky because they can thrive in cold conditions that stop other bacteria. “It likes places that are cold and wet and where there is something it can grow on,” says Dr. Robert Tauxe, who helps lead the foodborne diseases division at CDC. “Unfortunately, food factories with good refrigeration systems are a place Listeria is known to hang out. It takes some care and it takes specifically looking for it and disinfecting when it is found. It is a challenge to many food factories.”
“When Listeria bacteria get into a food processing factory, they can live there for years, sometimes contaminating food products,” CDC says. Listeria appear to have been living in two Blue Bell ice cream factories for five years or longer, causing occasional illnesses, CDC says.
While cooking and pasteurization kills Listeria, it can get into cooked food during the packaging process.
It can be deadly
CDC estimates that Listeria puts 1,600 people into the hospital each year and kills 260 of them. Most at risk are people with weakened immune systems, such as the elderly, very young children and pregnant women. Listeria can cause miscarriages and it can infect newborns. Listeria can cause bloodstream infections and fatal bacterial meningitis. Anyone with a fever and stiff neck should seek medical attention right away.
It’s all around
Listeria monocytogenes, the bacteria that causes listeriosis, is commonly found in soil and water. Animals can carry Listeria without appearing ill, and their meat and milk can be contaminated. Because it’s in the soil, Listeria can contaminate plant foods. Recent outbreaks have been traced to bean sprouts, apples and cantaloupe.
You can’t always wash it off
Poor sanitation at a Colorado cantaloupe farm was blamed for a 2011 outbreak of listeriosis that killed 33 people. Experts said the bacteria can get into the nooks and crannies of rough cantaloupe rind and be carried into the flesh of the fruit when cut.