WASHINGTON (AP) -- Blue Bell Creameries is pulling all of its products off the shelves after samples of its ice cream tested positive for a potentially deadly bacteria - listeria.
The recall announced late Monday includes ice cream, frozen yogurt, sherbet and frozen snacks distributed in 23 states and abroad. It follows several smaller Blue Bell recalls over the last month that the company initiated after its products were linked to three deaths at a Kansas hospital.
Seven other listeria illnesses in Kansas, Texas, Oklahoma and Arizona over the last five years have now been linked to Blue Bell products, the Centers for Disease Control and Prevention said Tuesday. The agency worked with state health departments to match blood or stool samples from past listeria patients to the current strains.
A look at the listeria bacteria and answers to questions that consumers may have:
WHAT IS LISTERIA?
Listeria is a hardy bacteria found in soil and water that can be tracked into a plant or carried by animals. It can be very hard to get rid of once it contaminates a processing facility, partly because it grows very well in refrigeration. It is commonly found in processed meats, unpasteurized cheeses and unpasteurized milk, and it is sometimes found in other foods as well - listeria in cantaloupes was linked to 30 deaths in a 2011 outbreak. It hasn't commonly been found in ice cream, since it can't grow in freezing temperatures.
WHAT ARE THE SYMPTOMS?
When a person contracts the disease, it can cause fever, muscle aches, gastrointestinal symptoms and even death.
AM I AT RISK?
Listeria generally only affects the elderly, people with compromised immune systems and pregnant women. It can cause miscarriage, stillbirth, premature labor, and serious illness or death in newborn babies. Healthy, younger adults and most children can consume listeria with no ill effects or mild illness.
WHAT HAS BEEN RECALLED?
As of Monday, Blue Bell ice cream has recalled all of its products. That follows more limited recalls of Blue Bell products made on production lines in Texas and Oklahoma after the ice cream was linked to the deaths in Kansas. The company issued Monday's recall after two samples of chocolate chip cookie dough ice cream tested positive for listeria.
HOW DID THIS HAPPEN?
The company says it "cannot say with certainty" how the bacteria was introduced to its facilities. State and federal inspectors are still investigating the outbreak and have not released a cause. In past outbreaks, contamination has been the result of dirty equipment or unsanitary conditions in a plant. Dr. Robert Tauxe of the CDC says contaminated equipment is "the usual scenario" in listeria outbreaks.
I HAVE BLUE BELL PRODUCTS IN MY HOME. WHAT DO I DO?
You should throw them out. When you throw something away, place it in a closed plastic bag in a sealed trash can to prevent animals or other people from eating it. The ice cream can have a shelf life of up to two years.
ARE ANY BLUE BELL PRODUCTS SAFE TO EAT?
Not right now. The CDC and the Food and Drug Administration are warning consumers not to eat any Blue Bell products. Both agencies say they are continuing to investigate the outbreak.
HOW CAN I PROTECT AGAINST LISTERIA?
It's tough. In the case of the Blue Bell products, there's nothing you can do - just throw it away. Clean any surfaces that may have touched the food with hot, soapy water.
If you are in one of the groups that is most vulnerable to listeria, heat processed meats to 165 degrees Fahrenheit or until it is steaming hot just before serving it.
For fruit, scrubbing is never a bad idea, but it may not rid produce of all contaminants. In the case of the cantaloupe, the listeria likely hid on the fruit's thick, rough skin. Health officials think people may have been sickened when people cut into their cantaloupes, bringing listeria on the outside of the fruit to the inside.
WHY IS LISTERIA SO DEADLY?
Listeria is less well-known but much more deadly than other pathogens like salmonella and E. coli, which cause many more illnesses in tainted food every year. One in five people who get sick from listeria can die. The people who get sick from listeria are often already weaker and more vulnerable to disease.
HAVE THERE BEEN OTHER RECENT RECALLS DUE TO LISTERIA?
Yes. Earlier this month, Sabra Dipping Co. announced a recall of 30,000 cases of its Classic Hummus, also due to possible listeria contamination. No illnesses have been linked to that recall.
In January, a California company recalled Granny Smith and Gala apples after samples of listeria found in its plant matched listeria bacteria that sickened 32 people across the country, including at least three deaths. The illnesses and deaths were linked to consumption of caramel apples.
Food and Drug Administration updates on the Blue Bell listeria outbreak:
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Copyright 2015 The Associated Press modified.