An illness that people often get from eating something contaminated with the Listeria bacterium is called listeriosis. It is usually found in deli meats, hot dogs, and soft cheeses. People who develop it may experience the following symptoms. These include fever, headaches, and diarrhea. Moreover, listeriosis can cause serious complications if you are pregnant or have a weakened immune system. Doctors usually prescribe antibiotics to treat this condition.
Generally, this condition occurs rarely, and it affects about 1,600 people in the U.S. each year.
What Are The Symptoms of Listeriosis?
Typically, the symptoms appear within a few days after exposure to this bacterium. Check some symptoms below:
- Fever
- Diarrhea
- Chills
- Headaches
- Fatigue (extreme tiredness)
- Nausea
- Vomiting
- Muscle or joint pain
- Diarrhea
Some people may experience additional symptoms, but they occur only when the bacterium spreads beyond the digestive system (invasive listeriosis). Check some of them below:
- Neck stiffness
- Seizures
- Loss of balance
- Confusion
Immediately contact your healthcare professional if any of the symptoms listed above occur. Otherwise, it may lead to certain serious complications.
Causes and Risk Factors
This infection happens due to a bacterium called Listeria monocytogenes. It enters the body through contaminated food or fluids (such as water). If you get this bacterium and you are pregnant, it may pass to your developing fetus. Check below for some foods that are more likely to be contaminated with this bacterium:
- Cold cuts, hot dogs, and deli meats
- Cold-smoked fish (such as lox)
- Soft cheeses (these include Brie, Camembert, and queso fresco)
- Unpasteurized dairy products (such as milk, cheese, and ice cream)
- Raw or unwashed fruits and vegetables (especially melon)
- Sprouts
- Unpasteurized fruit juices (including apple cider)
- Raw sushi
While anyone can develop a severe form of listeriosis, the following factors significantly increase your risk. Examples include:
- Age – People over 65 years old are more likely to develop a severe infection.
- Newborns – Babies who get this infection may develop severe complications, including neonatal sepsis or meningitis.
- Weakened immune system – The immune system can be compromised due to cancer, HIV infection, immunosuppressants, and others.
- Pregnancy – During pregnancy, the body causes natural and physiological downregulation of cell-mediated immunity, which leads to an increased risk of getting listeriosis.
This bacterial infection is not contagious. It means it does not spread from one person to another.
What Are The Potential Complications of Listeriosis?
Usually, people with listeria experience complications when the bacterium spreads from the digestive tract to other parts of the body. Check some complications below:
- Endocarditis (inflammation of the heart)
- Osteomyelitis (bone infection)
- Peritonitis (inflammation of the tissues that line the abdominal organs)
- Encephalitis (inflammation in the brain and spinal cord)
- Meningitis
- Pregnancy complications (these include preterm birth, stillbirth, and miscarriage)
- Pneumonia
- Sepsis
- Septicemia
- Urinary tract infections (UTIs)
- Death
Babies who are born with listeriosis or when the infection spreads to the brain, it may cause additional complications. For example, organ damage or failure, seizures, paralysis, blindness (a complete loss of vision), and developmental delays.
Is There a Way to Prevent Listeriosis?
Healthcare professionals usually recommend the following tips to reduce the risk of getting listeriosis. Examples include:
- Do not consume unpasteurized dairy products and juices (including milk, cheese, and ice cream)
- Regularly wash your hands and food surfaces before and after cooking
- You should use a scrub brush and clean raw fruits and vegetables
- Cook hot dogs, egg dishes, and seafood at proper temperature (about 165 degrees F or 74 degrees C)
- Avoid refrigerated pate or meat spreads if you are pregnant
Diagnosis
It is not possible to know you have this infection unless you get tested. Moreover, people with mild symptoms may never get tested. When doctors confirm or rule out listeriosis by performing a blood test or getting cerebrospinal fluid (CSF) for testing. In some cases, they can diagnose this condition during pregnancy by testing the amniotic fluid. Check below for other tests that may also help detect listeriosis:
- Testing tissue from the placenta
- Blood culture
- CT (computerized tomography) scans
- Brain MRI (magnetic resonance imaging) scans
Treatment
Doctors usually prescribe antibiotics (such as Ampicillin or Sulfamethoxazole) to treat this infection. It is very important to administer antibiotics exactly as recommended by your doctor. Otherwise, the infection may return, and it becomes more difficult to treat. However, people who experience mild symptoms usually do not need treatment.
Frequently Asked Questions
How long does it take for listeriosis symptoms to appear?
Symptoms usually develop within a few days after eating contaminated food, but they can appear anywhere from the same day up to 70 days later. In pregnant people, symptoms may be mild or absent even when the infection affects the baby.
What foods are most commonly linked to listeriosis?
Common sources include deli meats, hot dogs, soft cheeses made from unpasteurized milk, refrigerated smoked seafood, raw sprouts, unpasteurized dairy products, unpasteurized fruit juices, and contaminated fresh produce such as melons.
Can healthy adults recover from listeriosis without treatment?
Yes. Many healthy adults experience only mild gastrointestinal symptoms that resolve on their own. However, people at high risk, including pregnant individuals, older adults, newborns, and those with weakened immune systems, should seek medical attention promptly.
Is listeriosis contagious?
No. Listeriosis is not usually spread from person to person. Most infections occur after eating food contaminated with Listeria monocytogenes. However, a pregnant person can pass the infection to the developing fetus during pregnancy or childbirth.
Why is listeriosis especially dangerous during pregnancy?
Although pregnant people often experience only mild flu-like symptoms, the infection can cross the placenta and lead to miscarriage, stillbirth, premature birth, or severe infection in the newborn. Early diagnosis and treatment with antibiotics can help reduce these risks.
How is listeriosis diagnosed?
Doctors usually diagnose listeriosis by identifying the Listeria bacteria in a blood culture or another body fluid, such as cerebrospinal fluid. During pregnancy, amniotic fluid or placental tissue may also be tested if an infection is suspected.
Can listeriosis affect the brain?
Yes. In severe cases, the bacteria can spread to the central nervous system, causing meningitis or encephalitis. Symptoms may include severe headache, neck stiffness, confusion, loss of balance, seizures, and altered mental status. These symptoms require immediate medical care.
How can I reduce my risk of getting listeriosis?
You can lower your risk by eating only pasteurized dairy products, thoroughly washing fruits and vegetables, reheating deli meats and hot dogs until steaming hot, cooking foods to safe internal temperatures, practicing good kitchen hygiene, and avoiding high-risk foods if you are pregnant or have a weakened immune system.
Can listeriosis come back after treatment?
Most people recover completely when treated appropriately with antibiotics. However, failing to complete the prescribed course of antibiotics or having a severely weakened immune system may increase the risk of persistent or recurrent infection.
When should I seek medical attention for listeriosis?
Contact your healthcare provider immediately if you develop a fever, severe diarrhea, persistent vomiting, confusion, neck stiffness, seizures, or loss of balance after eating potentially contaminated food. Pregnant individuals, older adults, newborns, and people with weakened immune systems should seek medical advice even if their symptoms seem mild. Do not hesitate to contact your healthcare professional if you have additional questions.
