CDC says nine deaths from listeria tied to tainted deli meats

NOW WITH THE GROWING NUMBER OF DEATHS FROM A LISTERIA OUTBREAK BEING TIED TO TAINTED BOAR'S HEAD DELI MEAT. AT LEAST NINE PEOPLE HAVE DIED. NBC'S ANNE THOMPSON HAS THE LATE DETAILS. >> Reporter: THIS IS THE WORST OUTBREAK OF LISTERIA IN 13 YEARS. 57 PEOPLE HOSPITALIZED. NINE PEOPLE DEAD INCLUDING SIX SINCE THE LAST UPDATE EARLIER THIS MONTH. ONE FROM FLORIDA, TENNESSEE, NEW MEXICO, NEW YORK, AND TWO PEOPLE FROM SOUTH CAROLINA. ORIGINALLY LINKED TO BOAR'S HEAD LIVERWURST, THE RECALL NOW INCLUDES 7 MILLION POUNDS OF MEAT WITH EITHER EST-12612 OR P-12612 INSIDE THE USDA MARK OF INSPECTION ON PRODUCT LABELS. IF YOU HAVE THESE MEATS, THE CDC SAYS THROW THEM AWAY. >> LISTERIA IS A SERIOUS INFECTION. IT'S THE MOST DEADLY FORM OF FOOD POISONING. >> Reporter: IN A STATEMENT TODAY, BOAR'S HEAD SAID, IT REGRETS THE IMPACT OF THIS RECALL AND WE FEEL FOR THOSE WHO HAVE SUFFERED LOSSES OR ENDURED ILLNESSES. THE CDC SAYS LISTERIA IS A HARDY JOB THAT CAN LINGER ON MEAT SLICERS AND FOODS EVEN WHEN REFRIGERATED. SYMPTOMS CAN APPEAR THE SAME DAY OR UP TO TEN WEEKS LATER. THE SYMPTOMS INCLUDE HEADACHE, CONFUSION AND CONVULSIONS ALONG WITH FEVER AND MUSCLE ACHES. >> ALL RIGHT, ANNE JOINS US NOW IN STUDIO. SO, ANNE, WHO IS AT MOST RISK FOR LISTERIA INFECTIONS? >> TOM, THERE ARE THREE GROUP, FIRST OF ALL, PREGNANT WOMEN, ANYBODY OVER THE AGE OF 65 AND ANYONE WHO IS IMMUNOCOMPROMISED. IF YOU ARE -- IF YOU FALL IN THOSE CATEGORIES, PLEASE DO NOT EAT MEAT THAT IS SLICED AT DE