How Does Listeria Get into Ice Cream?

Summer is here. This is my absolute favorite time of the year but for some not so obvious reasons. My favorite ice cream spots open back up. We tend to enjoy loading up into the car as a family after dinner (okay sometimes before dinner, too) and going to get ice cream. Some special flavors I love are banana and peach of course which so happen to be seasonal. A good dreamsicle you can’t go wrong with either.

I always thought of this as being a safe type of food mostly because it is frozen and usually made with fresh ingredients, but alas there have been Listeria outbreaks in several ice cream brands over the past few years.

How does this happen?

In doing some digging it appears that some folks became ill and were hospitalized and tested positive for listeria. This boils down to sanitation. It appears that when inspected the facility in one of the most recent ice cream outbreak scenarios didn’t have proper sanitation methods in place and these were identified as environmental before packaging. Where were the pathogens? They were found on a stainless-steel door and on a gasket attached to the machine that manufactures soft-serve ice cream. They were found on other surfaces as well, but a gasket?!  This proves that these pathogens can reside just about anywhere and without strict protocol they can really cause serious illness and even in some cases death.

With the popularity of people making more things at home and using new kitchen tools it is important to know that every surface including ones that may skip your mind are extremely important to clean. This ensures that they are clean, safe and most importantly function to their full potential so that you and your family can enjoy your homemade ice cream.

What is Listeria?

Listeria monocytogenes (L. monocytogenes) is a type of disease-causing bacteria that can be found in many places, including soil, water, sewage, rotting vegetation, and animals. It can survive and grow even under refrigeration. L. monocytogenes can thrive in unsanitary food production conditions, leading to contamination of the food. When people eat food contaminated with L. monocytogenes, they may develop a disease called listeriosis.

L. monocytogenes is generally transmitted when food is harvested, processed, prepared, packed, transported, or stored in manufacturing or production environments contaminated with L. monocytogenes. Environments can become contaminated by raw materials, water, soil, and incoming air. Pets can also spread the bacteria in the home if they eat food contaminated with L. monocytogenes.

Listeriosis has a range of symptoms that can vary based on the severity and form of the illness. There are two forms of the disease: the less severe, non-invasive gastrointestinal listeriosis, and the more severe form, invasive listeriosis, which occurs when the Listeria spreads beyond the intestines.

For the less severe, non-invasive listeriosis, mild symptoms such as fever, muscle aches, nausea, vomiting, and diarrhea may occur, and often persists for 1 to 3 days.

For the more severe, life-threatening invasive form of the disease, symptoms may include headache, stiff neck, confusion, loss of balance, and convulsions. Invasive listeriosis is a potentially life-threatening event, especially for newborns, adults over the age of 65, and those with weakened immune systems.

Symptoms of listeriosis during pregnancy may be mild or even go unnoticed, but can lead to severe outcomes, such as miscarriage, stillbirth, premature delivery, or a life-threatening infection of the newborn.

You should immediately consult with your healthcare provider if you suspect you’ve developed symptoms that resemble a listeriosis infection.

Pregnant women and their unborn or newborn baby, adults over the age of 65, and those with weakened immune systems, are all considered to be high-risk groups that are susceptible to the serious and adverse effects of listeriosis.

Pregnant women and their unborn or newborn baby:

• Changes during pregnancy alter a person’s immune system, making pregnant women more susceptible to L. monocytogenes
• While listeriosis can present as a mild disease in pregnant woman, the infection can lead to serious complications with their pregnancy, including miscarriage and stillbirth.
• If a pregnant woman becomes infected with L. monocytogenes, the bacteria can cross into the placenta and infect their unborn baby, whose immune system is not fully developed and is unable to fight off the infection.
• Babies born with a listeriosis infection may develop severe health complications that require immediate medical attention. The infection can lead to lifelong health problems or result in death.
• Pregnant women who suspect they have symptoms of listeriosis (see section below) should seek medical care immediately and tell their health care provider what they ate.

Adults over the age of 65 and people with weakened immune systems:

• As people age, their immune system becomes less effective at recognizing and eliminating harmful germs that may cause infections. This delay gives harmful germs, like L. monocytogenes, an opportunity to grow and spread within their victim.
• The immune systems of transplant patients and people with certain illnesses, such as HIV/AIDS, cancer, diabetes, and autoimmune diseases, are often weakened from the disease process and/or the side effects of some treatments, making it less able to fight off certain infections, such as listeriosis.
• People over the age of 65 or who have weakened immune systems are at greater risk of serious health complications resulting from listeriosis, including death. People in these categories who develop symptoms of listeriosis (see section below) should seek medical care immediately and tell their health care provider what they ate.

For more information on food safety and recalls please keep an eye on Make Food Safe.