The number 97B represents the plant where the listeria-tainted cured meats were produced. Maple Leaf Foods issued a recall of all cured meats with that number. Avoid these meats, or throw them out if you already have them.
Other brand names may also have dangerous meats from the same source. They are: Schneiders, Hygrade, Parma, Hickory Farms, Shopsy's, Western Family, Artisan Collection, Compliments, Campfire, Overlander and Safeway (National Post). Restaurants like Mr. Sub, and MacDonalds, possibly Tim Horton's may also use Maple Leaf meats.
Listeria is a bacterium that obviously may be found in food. Preventing it is done by sanitizing food contact surfaces.
Already 4 people have died, 21 others are confirmed to have been infected by it, and more are being investigated. What's scary about this illness is that symptoms may not appear until 90 days after the meat had been consumed, and in most cases, 30 days. Symptoms include vomiting, nausea and diarrhea. Most peoples' immune systems can fight it off, but unfortunately some peoples' can't.
It's another wake up call to the meat industry, restaurants, and anyone handling meat, to be ever so cautionary when handling meat.
Update: 16 deaths have now been linked to the listeriosis outbreak.