Cantaloupes and Listeria monocytogenes


What you need to know about the cantaloupe-Listeria outbreak:


As you’ve probably learned by now, at least 100 people in 20 states have been sickened and 18 have died from cantaloupe that was contaminated with Listeria monocytogenes.


This particular outbreak, involving cantaloupe grown from Jensen Farms in Colorado, is troubling because it involves a food that many people love to eat.  Most of the outbreak victims have been over 60 years of age, but two pregnant women have also been infected.


What you need to know about the contaminated product and clean-up:


Cantaloupes have a rough, but porous rind.  It is nearly impossible to clean all of the nooks and crannies and even if you could, there is a risk that your efforts will force the bacteria inward.  Further, cutting the cantaloupe transfers the Listeria on the rind into the fruit, so when cantaloupe is contaminated, you basically have to throw it out.

Listeria is a hardy bacterium and it can remain alive in your reusable shopping bag, on your countertops and even in your refrigerator for months after you have discarded the contaminated item.


So, even if you threw away a recalled cantaloupe, the bacteria can still be thriving in your kitchen and causing contamination.  And, that can make you and other people sick.  So, it’s time to roll up your sleeves - you have some work to do!


If the fruit was in your refrigerator, throw away anything that was near it.

Wash and sanitize the inside walls and shelves of the refrigerator with a bleach solution of one tablespoon of chlorine bleach to one gallon of water.  Apply the solution to the surface and let it “sit” for a few minutes, then dry with a fresh and clean cloth or paper towel.

Likewise, clean and disinfect your countertops and cutting boards.

Wash your dishrags and reusable grocery bags in hot water with chlorine bleach.

Sponges should be discarded – no amount of disinfectant can make them safe.

And of course, after you are done, wash your own hands with soap and water.


What you need to know about the illness (listeriosis):


Listeria typically causes gastrointestinal symptoms, along with fever and muscle aches.  The elderly, pregnant women, and those with compromised immune systems (especially those with AIDS) are most at risk.  In healthy adults and children, listeriosis is very rare. However, for the vulnerable populations, it can be a deadly disease and has a very high death rate – 20%. The long-term health outcomes associated with listeriosis are moderate-serious neurological problems, including seizures; for pregnant women, miscarriage, premature birth and stillbirth can be outcomes.


If you believe that you have eaten contaminated product and are sick, seek medical attention immediately so that proper treatment can be started.  Keep in mind that listeriosis has a long incubation period and symptoms may not appear for weeks or even months after eating the contaminated food.


Preventing listeriosis in pregnant women, senior citizens and people with compromised immune systems is very important because of the high death rate.


Learn the foods that can carry Listeria monocytogenes and encourage people in the high risk groups, named above, to avoid the risk by making different food choices.


Foods to avoid because they carry a high risk for Listeria monocytogenes:

Raw milk

Soft cheeses, including feta, queso blanco, queso fresco, brie and Camembert -- blue veined or panela – UNLESS the label says MADE WITH PASTEURIZED MILK.

Hot dogs, lunch meats, cold cuts, deli meats, fermented or dry sausage UNLESS they are heated until steaming hot just before eating.

Refrigerated pâté or meat spreads from a deli or meat counter or from the refrigerated section of a store. Foods that do not need refrigeration, like canned or shelf-stable pâté and meat spreads, are safe to eat. Refrigerate after opening.

Refrigerated smoked seafood, such as salmon, trout, whitefish, cod, tuna, mackerel UNLESS it is contained in a cooked dish, such as a casserole, or unless it is a canned or shelf-stable product.  Frequently these refrigerated seafood products are labeled as “nova-style,” “lox,” “kippered,” “smoked,” or “jerky.”


Note:  Handling these products before they are cooked or pasteurized carries a risk for transmitting the bacteria to the food handler and/or other food or surfaces.


For additional information on the recent cantaloupe outbreak and listeriosis:


To learn about the recent recall of chopped, Romaine lettuce contaminated with Listeria monocytogenes:

For more information on the long-term health outcomes of foodborne illnesses, read CFI's report or poster on The Long-Term Health Outcomes of Selected Foodborne Pathogens.