Currently browsing posts about: Listeria

Feb 8 2012

Listeria in hard-boiled eggs? How come?

A company called Michael Foods has recalled more than one million hard-boiled eggs because of possible contamination with Listeria monocytogenes.  These especially nasty bacteria grow happily at refrigerator temperatures.

Michael Foods packaged the eggs in buckets of brine at a facility in Wakefield, Nebraska.  Investigators suspect a room in the packaging plant as the most likely source of contamination.  Listeria do tend to lurk in wet crevices of packing plants.

The company’s recall notice says:

None of the eggs were sold directly by Michael Foods to retailers or consumers. However, food distributors and manufacturers who purchased the eggs could have used them in products that were sold to retail outlets or used in foodservice settings.

Think: commercially prepared egg salad sandwiches and potato salads.

If you can’t quite get how a million hard-cooked eggs could be exposed to Listeria, you have plenty of company, mine included.

Hard-boiled eggs are boiled.  They are sterile.  What could have happened?

I went to the Web to find out how eggs are processed for commercial use, and discovered the Sanovo Group.   This company produces machines that wash and peel hard-boiled eggs (check the video).

The company’s SB 20000 Egg Boiler, for example:

automatically boils, cools and peels up to 20,000 eggs/hour. It can handle both brown and white eggs [Huh?  Why would anyone expect a difference?]….The SB 20000 Egg Boiler centres the yolk on stainless steel rollers, improving the egg quality and yield. A uniform boiling of the eggs is obtained by the built-in conveyor working with up to 18 minutes boiling time.

The boiled eggs are cooled for 23 minutes in the SC 20000 Egg Cooler, improving the peeling of the eggs. Ice water is injected in the centre of the cooling drum for optimal cooling transmission to the egg.

The SP 20000 Egg Peeler gently cracks the eggshells. Using the hygienic and no-scratch peeling technique. The complete system is easily cleaned for optimal hygiene.

The contamination must have occurred after the eggs were peeled or while they were in the buckets.

To me, the mere thought of peeled, hard-cooked eggs sitting in pails of cold, Listeria-friendly salt water for who knows how long be should make anyone run for the nearest testing kit.

These egg recalls are a perfect example of the hazards of industrial-scale food production.

Support your local egg farmer and peel your own eggs!

Sep 29 2011

Since when did cantaloupe become a WMD*?

Are you as puzzled about the latest cantaloupe outbreak as I am?  This time it’s Listeria again (see previous post on this particular pathogen).

According to the CDC, 72 people have been infected with the strains of Listeria associated with the outbreak in 18 states.  Most appalling,  13 people have died.

The CDC says that the people who have become ill range from 35 to 96 years, with a median age of 78 years.  Most are over age 60 or have health conditions that weaken the immune system.  Pregnant women are at especially high risk as are their fetuses.

As always, the recall occurred after most of the cases were reported to the CDC.  The cantaloupe were traced to Jensen Farms, which issued a recall on September 14.

Why cantaloupe?  They are, after all, grown in dirt and their skin is rough, textured, and has plenty of places for bacteria to hide.  People pick up Listeria by handling the fruit and cutting into it.  FDA’s information page lists the recalls and press releases on the Jenson Farms outbreak.

The FDA’s advice: throw it out.

Do not try to wash the harmful bacteria off the cantaloupe as contamination may be both on the inside and outside of the cantaloupe. Cutting, slicing and dicing may also transfer harmful bacteria from the fruit’s surface to the fruit’s flesh.

What do food safety experts say you have to go through to avoid getting sick from eating cantaloupe?

  • Wash the melon under running water with a clean vegetable brush.
  • Blot with paper towels to remove excess water.
  • Put melon on a clean surface, one that hasn’t come into contact with meat or poultry or other foods that could cause cross-contamination.
  • Cut off the stem end about 3/4 to 1 inch from the end, using a clean kitchen knife.
  • Place melon on a clean cutting board, plate, or other clean surface with the cut end facing down.
  • Using a clean knife, cut the melon from the blossom end to the stem end.
  • Follow this by washing the knife with clean running water and setting it aside.
  • Gently scrape out the seeds with a clean spoon and cut the melon into slices or whatever is desired.
  • Don’t use dish soap or detergent; cantaloupes can absorb detergent residues.
  • Do not allow the rind to touch any part of the edible fruit.
  • Melon that isn’t eaten should be peeled, covered and refrigerated.
  • Discard any melon that has been at room temperature for longer than 2 hours, or 1 hour when the temperatures are over 90 degrees F.
  • Follow these procedures for all melons, no matter where they were grown.

What?  No HazMat suit?

We are talking about cantaloupes here.

How about a food safety system where everyone makes sure—and tests—that Listeria don’t get on cantaloupe in the first place.

Single food agency anyone?

_____

*Translation: Weapon of Mass Destruction

Mar 26 2010

San Francisco Chronicle: Listeria bacteria hysteria

My most recent column in the San Francisco Chronicle appeared later than usual (March 14) so I forgot to post it when it came out.  It deals with Listeria in pregnancy:

A guide to avoiding Listeria

Nutrition and public policy expert Marion Nestle answers readers’ questions in this monthly column written exclusively for The Chronicle. E-mail your questions to food@sfchronicle.com, with “Marion Nestle” in the subject line.

Q: I miscarried at 19 weeks of pregnancy. My doctor said my placenta was infected with Listeria, only her second case in 20 years of practice. I am your typical Bay Area food lover. I thought if I knew the sources of most of my food, I’d be safe. What is safe for pregnant women to eat in the post-Michael Pollan era?

A: Thanks for allowing your personal tragedy to alert others to this hazard. Losing a wanted pregnancy is a heartbreak. Losing one to a food-borne illness is especially tragic. Such illnesses should be preventable.

Food should be safe before it gets to you. That it sometimes is not is a consequence of our inadequate food safety system, which does not require food producers to test for harmful bacteria. The House of Representatives passed legislation that does so last summer, but the Senate is sitting on it. As an individual, you cannot easily protect yourself against invisible hazards in food. Congress must pass that legislation.

Without federal requirements, you are on your own to keep yourself and your unborn infant safe from food pathogens, especially Listeria. Much as I hate to add to what the French sociologist Claude Fischler calls “Listeria bacteria hysteria,” I must. Listeria preferentially affects pregnant women. If you are pregnant and want to stay pregnant, you must avoid Listeria.

This will not be easy. Listeria is widely dispersed in foods. Infections from it may be rare, but they are deadly. Listeria kills a shocking 25 percent of those it infects and is particularly lethal to fetuses.

Most people, including pregnant women, are immune to Listeria and do not feel ill when infected. But unlike most bacteria, Listeria penetrates the placenta, and fetuses have no immunity. The first sign of an infection can be a miscarriage or stillborn infant – too late for antibiotics.

How worried should pregnant women be about Listeria? Given our ineffective food safety system, I’d advise caution. The Centers for Disease Control and Prevention report 2,500 cases a year and 500 deaths. These numbers are minuscule – unless your pregnancy is affected.

Cases occur mainly among the young, the old and others with poor immunity. But the cause of miscarriages is not typically investigated, and I’m guessing that fetal deaths from Listeria are badly underreported.

Animals and people often excrete Listeria from their digestive tracts, even when they show no signs of illness. The bacteria get into food from infected animal waste and unwashed hands.

As a result, unpasteurized milk products and contaminated raw vegetables are frequent food sources. Other sources depend on yet another of Listeria’s nasty features – Listeria grows, reproduces and flourishes at refrigerator temperatures that stop other bacteria cold.

This explains why the CDC strongly advises pregnant women not to eat potentially undercooked foods stored in refrigerators: hot dogs, lunch meats, deli meats, patés, meat spreads and smoked seafood (salmon, trout, lox, jerky); soft cheeses such as feta, Brie, Camembert, those with blue veins, and especially Mexican “queso blanco fresco”; and raw milk or foods containing unpasteurized milk.

Even though some of these foods were cooked or pasteurized to begin with – blue cheese, for example – they can become contaminated after processing. Days or weeks of refrigeration give Listeria ample time to reproduce. Just about any food sitting around in a refrigerated package can be a source, with meat, fish and dairy foods especially suspect.

The CDC advises following safe food handling procedures to the letter at home. Avoid cross-contaminating raw and cooked foods, and use refrigerated perishables right away.

Listeria infections were virtually unknown 25 years ago, so view this hazard as collateral damage from the consolidation and centralization of our industrialized food supply.

Do not despair. There is some good news. Cooking kills Listeria. Pregnant women still have plenty of options for good things to eat that are safe.

Anything cooked hot is safe. So are hard cheeses, semisoft cheeses like mozzarella, pasteurized processed cheeses, and cream and cottage cheeses. These were cooked or are now too dry and salty for bacterial growth. Anything canned – patés, meat spreads, smoked fish, other fish – also is safe.

When it comes to food hazards during pregnancy, Listeria is unique. A sip of wine every now and then is not going to induce fetal alcohol syndrome, nor will your baby get mercury-induced brain damage from an occasional tuna sandwich. The risks from such hazards accumulate with amounts consumed over time.

But the risk from Listeria is acute. With so much at stake, and so many other food choices available, why take chances?

Just last month, the Food and Drug Administration reported recalls of queso fresco, blue cheese and bean sprouts because of possible Listeria risk. The FDA is doing its best, short of legislation. To keep Listeria out of the food supply, Congress needs to act. Write your representatives now.

Marion Nestle is the author of “Food Politics, “Safe Food” and “What to Eat,” and is a professor in the nutrition, food studies and public health department at New York University. E-mail her at food@sfchronicle.com and read her previous columns at sfgate.com/food.