Listeria And Ice Cream: What You Need To Know About Blue Bell And Bacteria

Blue Bell Creameries has pulled all of its products from store shelves after samples of a few products tested positive for contamination by a bacteria called listeria.

It is a hardy germ that lives in water and soil that's been contaminated by animals, and it apparently has made its way into a Blue Bell facility -- where it can survive for years in a cold environment. Once in equipment, it can be very difficult to get rid of. The germ survives well in chilly temps.

So why the concern? Listeria can be deadly bacteria. And like many germs is especially dangerous to the very old, the very young, people with weakened immune systems --and pregnant women. If pregnant women consume something with listeria in it, not only can they become ill, but they are at risk for miscarriage and premature birth.

RELATED: Blue Bell Recalls All Products After Listeria Outbreak

Healthy people generally do not get sick from listeria -- meaning healthy adults and older children. In fact, it's believed that 10 percent of the population carries the germ without ill effect.

We are not quite sure of the incubation. Outbreaks are hard to discover, and then track.

It's thought that Blue Bell may have had contamination well before this series of cases, possibly as far back as 2010. And no one, until know, connected the dots and thought about ice cream as the cause. DNA testing and other detective work has helped discover it.

And if you recall, there was a major outbreak just a few years ago finally traced back to contaminated cantaloupe.

Symptoms are wide ranging -- all of the way from the following:

- None, or mild "I might have a small touch of stomach flu"
- Fever, chills, and aches
- Nausea
- Stomach and abdominal pain
- Diarrhea
- Dehydration
- And in severe cases in high risk groups: death

If you think you have eaten any of the products in question (and it's not only ice cream), and you don't feel well, come see us. We can run tests and cultures. Those severely ill need hospitalization and other treatments.

As for everyone else, if you have any Blue Bell products in your house, they should be discarded. No question. Discarded. Don't risk a potentially deadly illness.

The detective work continues.

Dr. Dave Hnida is CBS4's Medical Editor. He blogs about the latest studies and trends in the health world. Read his latest blog entries, check out his bio or follow him on Twitter @drdavehnida