What is Listeria?

Posted on July 11, 2025 by Patrick Hercules

Many food products have been recalled over the past few months due to various outbreaks of listeria.

Listeria or Listeria monocytogenes is a species of pathogenic or disease-causing bacteria found in moist environments, soil, water, decaying vegetation, and animal feces. It can survive and even grow under refrigeration and other food preservation measures.

Most people encounter listeriosis, a foodborne illness, as it can be found in hot dogs, deli meats, fresh vegetables, fresh fruits (especially melons), and unpasteurized dairy products. These foods have the highest risk of being contaminated by Listeria bacteria. However, any food that is handled or prepared improperly can be affected.

Listeria bacteria are unique from many other foodborne illnesses because they survive and multiply in low temperatures, including refrigerators and freezers. It can multiply to dangerous levels during storage, and it doesn’t change the smell, taste, or texture of the food that it contaminates, like other bacteria.

Most people get listeriosis from eating contaminated foods. The listeriosis incubation period (the time between when you’re first infected and when you first show symptoms) varies. It usually takes one to two weeks, but can be as short as a couple of days or as long as three months.

Symptoms of a listeria infection can include:

Fever

Chills

Muscle aches

Nausea

Diarrhea

If the listeria infection spreads to the nervous system, symptoms may include:

Headache

Stiff neck

Confusion or changes in alertness

Loss of balance

Convulsions

Those at risk of severe listeria infection include:

Pregnant women

People older than 65 years old

People with weakened immune systems

People suffering from chronic diseases

The most effective way to diagnose a listeria infection is a blood test. Samples of urine and spinal fluid may also be tested.

The treatment for a listeria infection varies depending on the severity of the signs and symptoms. Most people with mild symptoms require no treatment at all. Antibiotics can treat more serious listeria infections.

Some ways to prevent a listeria infection include:

Washing hands thoroughly with warm, soapy water before and after handling or preparing food. After cooking, use hot soapy water to wash utensils, cutting boards, and other food preparation surfaces.

Cleaning raw vegetables with a scrub brush or vegetable brush under running water.

Using a food thermometer to make sure meat, poultry, and egg dishes are cooked at a safe temperature.

If you or someone you know is experiencing symptoms of a listeria infection, you can visit Jamaica Hospital Medical Center’s Ambulatory Care Center. To schedule an appointment, please call (718) 206-7001. If you or someone you are with is experiencing an emergency, call 911 immediately.

All content of this newsletter is intended for general information purposes only and is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. Please consult a medical professional before adopting any of the suggestions on this page. You must never disregard professional medical advice or delay seeking medical treatment based upon any content of this newsletter. PROMPTLY CONSULT YOUR PHYSICIAN OR CALL 911 IF YOU BELIEVE YOU HAVE A MEDICAL EMERGENCY.

Listeria, What You Should Know

Posted on August 2, 2024 by Patrick Hercules

There have been products such as deli meats, vegetables, dips and salsas, and plant-based milk recalled due to a recent listeria outbreak.

Listeria or Listeria monocytogenes, is a species of pathogenic or disease-causing bacteria found in moist environments, soil, water, decaying vegetation, and animal feces. It can survive and even grow under refrigeration and other food preservation measures.

Most people encounter listeria or listeriosis as a foodborne illness as it can be found in hot dogs, deli meats, fresh vegetables, fresh fruits especially melons, and unpasteurized dairy products. These foods have the highest risk of listeria contamination. However, any food that is improperly handled or prepared can be affected.

The listeria bacteria is unique compared to other types of bacteria because it survives and multiplies in low temperatures, including refrigerators and freezers. It can multiply to dangerous levels during storage. It also doesn’t change the smell, taste, or texture when it contaminates food like other bacteria.

Most people get listeriosis from eating contaminated foods. The listeriosis incubation period (the time between when you first get infected and when you first show symptoms) varies. It usually takes one to two weeks. But it can be as short as a couple of days or as long as three months.

The symptoms of a listeria infection include:

Fever
Chills
Muscle aches
Nausea
Diarrhea

If the listeria infection spreads to your nervous system, symptoms may include:

Headache
Stiff neck
Confusion or changes in alertness
Loss of balance
Convulsions

Those at risk of severe infection from listeria include:

Pregnant women
People older than 65 years old
People with weakened immune systems
People suffering from chronic diseases

A blood test is often the most effective way to determine whether you have a listeria infection. Samples of urine and spinal fluid may also be tested.

The treatment of listeria infection varies depending on the severity of the signs and symptoms. Most people with mild symptoms require no treatment at all. More serious listeria infections can be treated with antibiotics.

Some ways to prevent a listeria infection include:

1) Keeping things clean- wash your hands thoroughly with warm, soapy water before and after handling or preparing food. After cooking, use hot, soapy water to wash the utensils, cutting boards, and other food preparation services.

2) Scrub raw vegetables- clean raw vegetables with a scrub brush or vegetable brush under plenty of running water.

3) Cook your food thoroughly- Use a food thermometer to make sure your meat, poultry, and egg dishes are cooked to a safe temperature.

If you or someone you know is experiencing symptoms of a listeria infection you can see a gastroenterologist at Jamaica Hospital Medical Center’s Ambulatory Care Center. To schedule an appointment, please call (718) 206-7001. If you or someone you are with are experiencing an emergency, call 911 immediately.

Tips To Make Sure the Ice in Your Freezer is Clean

Posted on June 7, 2019 by Michael Hinck

There is nothing more refreshing on a warm summer day than an ice-filled cold beverage, but before you host your next summer gathering, make sure that the ice you serve is clean and free of harmful bacteria.

While ice is rarely considered to be the source of trouble, there are good reasons to take a second look at how ice is dispensed in your own home. You may think most bacteria wouldn’t survive the icy conditions of a freezer. But they can. Bacteria and viruses such as listeria, E-coli and salmonella can live in freezing temperatures, meaning they may be alive in your ice cubes. With proper precautions however, you can eliminate the risk of these contaminants existing in the ice you serve.

Here are some tips:

Change Your Filter – Most ice makers in freezers use a secondary water filter to stop particles from contaminating the ice. To keep your ice clean, change the freezer’s water filter as frequently as the manufacturer recommends, about every six months.
Regular Cleaning – Don’t forget to defrost and deep clean your freezer at least once a year. As a rule of thumb, if the ice buildup in your freezer is a quarter-inch or thicker, then it’s time to defrost and clean it.
Use Ice Regularly – The slight melting and refreezing of cubes can allow pathogens to take hold. To avoid this, remove the ice storage bin from the freezer and dump any clumps into the sink. Since inactivity causes ice clumps to form, the easiest solution is to use the ice maker more frequently.
Organize Your Freezer – Make sure frozen foods are properly sealed or double-wrapped and avoid having them come into direct contact with ice in trays or bins. Also label all food with a use-by date and remove all expired foods from your freezer.
Don’t Use Your Hands – While all of the above tips are useful, the fact is that the most common way to spread germs is by placing unwashed hands in an ice container. Instead of using your hands, use a designated scooper or other tool to handle ice.

It is important to note that while the existence of contaminants in your ice might be disturbing to learn, the health risks associated with it is fairly minimal to the average immune system and the transmission of viruses are rare. Those more at risk are pregnant women, children, and people with a compromised immune system.

Regardless, it is always a good idea to take the proper precautions to reduce your chances of getting yourself or your guests sick.