What is Listeria?

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.