The CDC has issued a warning against bagged and prepackaged salads because Listeria originating from a Dole processing facility in Springfield, Ohio. There has been 1 confirmed death and 3 more suspected to be linked to this Listeria outbreak.

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Listeria is the name of a bacteria found in soil and water and some animals, including poultry and cattle. It can be present in raw milk and foods made from raw milk. It can also live in food processing plants and contaminate a variety of processed meats. 
The infection is typically treated with antibiotics or is simply eliminated by the immune system. Occasionally, listeria infection can lead to life-threatening complications.

These include:

A generalized blood infection (septicemia)
Inflammation of the membranes and fluid surrounding the brain (meningitis)
If the listeria infection spreads to your nervous system, symptoms will include:

Headache
Stiff neck
Confusion or changes in alertness
Loss of balance
Convulsions

If you experience fever, muscle aches, nausea or diarrhea, contact your doctor or go to the hospital. Each year in the U.S., the CDC estimates that 1,600 people get sick from Listeria infections and 260 people die. 

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Illnesses were reported in six states: Indiana, Massachusetts, Michigan, New Jersey, New York and Pennsylvania.

Those affected by the bacteria ranged in age from 3 to 83 years old, and included one woman who was pregnant. 12 people reported being hospitalized, including one person from Michigan who died as a result of listeriosis.

The outbreak is said to have affected other brands than Dole such as:

Fresh Selections
Simple Truth
Marketside
The Little Salad Bar
President’s Choice Organic.

States that received packaged salads from this facility include:

Alabama
Connecticut
Florida
Georgia
Illinois
Indiana
Kentucky
Louisiana
Michigan
Massachusetts
Maryland
Minnesota
Missouri
Mississippi
North Carolina
New Jersey
New York
Ohio
Pennsylvania
South Carolina
Tennessee
Virginia
Wisconsin

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The outbreak has also spread north of the border, where it’s affected products in Canadian supermarkets. Affected products can be identified by a product code beginning with the letter A 

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The CFIA has issued a federal recall that applies to 48 different Dole pre-packaged chopped salads, salad blends and kits, and nine different PC Organics brand leafy greens.

Dole has temporarily suspended operations at the Springfield processing facility and voluntarily withdrew from the market all of its Dole-branded and private label packaged salads processed at that location.

What To Do If You’ve Purchased These Products
Here are a few guidelines from the CDC:

Throw the packaged salad away in a closed plastic bag placed in a sealed trash can. This will prevent people and animals from eating it.
Wash the refrigerator drawer and other areas where the packaged salads were stored with hot water and soap.
Wash cutting boards, surfaces, and utensils used to serve or store packaged salads. If possible, use a dishwasher; otherwise, use hot water and soap, followed by sanitizing with a solution. A mix of hot water and vinegar works well.
Wash your hands with warm water and soap after cleaning up.
Additionally, monitor yourself and your family and call a doctor if you begin to notice any of the symptoms mentioned above.

How To Protect Your Family From Future Contamination
FDA recommendations the following step to protect your family form food-borne bacteria and illnesses.

When preparing food:

Rinse raw produce, such as fruits and vegetables, thoroughly under running tap water before eating, cutting, or cooking. Even if the produce will be peeled, it should still be washed first.
Scrub firm produce, such as melons and cucumbers, with a clean produce brush.
Dry the produce with a clean cloth or paper towel.
Separate uncooked meats and poultry from vegetables, cooked foods, and ready-to-eat foods.

To keep your kitchen clean:

Wash hands, knives, countertops, and cutting boards after handling and preparing uncooked foods.
Be aware that Listeria monocytogenes can grow in foods in the refrigerator. The refrigerator should be 40°F or lower and the freezer 0°F or lower.
Clean up all spills in your refrigerator right away–especially juices from hot dog and lunch meat packages, raw meat, and raw poultry.
Clean the inside walls and shelves of your refrigerator weekly with hot water and liquid soap, then rinse.

Learn more at http://www.fda.gov/Safety/Recalls/ucm482822.htm