Causes and Symptoms of Listeriosis
Listeriosis is a serious infection caused by eating food contaminated with the bacterium Listeria monocytogenes. The disease affects primarily pregnant women, newborns, and adults with weakened immune systems.
Approximately four to 19 cases of listeriosis are reported in Minnesota each year.
on this page:
Fact Sheets
Symptoms
Duration of Illness
Compilcations
Transmission
Fact Sheets
- Listeriosis Fact Sheet
Answers to frequently asked questions about listeriosis.
- Listeriosis
CDC; Fact sheet answers some common questions about listeria. Attention: Non-MDH link
- Listeria monocytogenes Risk Assessment Questions and Answers
Foodsafety.gov; Includes information on the disease, and risk assessment that FDA, FSIS and CDC conducted. Attention: Non-MDH link
Symptoms
Common symptoms include:
- fever
- muscle aches
- nausea
- diarrhea
People who are not in the high-risk categories usually have no symptoms at all.
Symptoms usually begin around 3 weeks after infection (range, 3-7 days).
If infection spreads to the nervous system, other symptoms may include:
- headache
- stiff neck
- confusion
- loss of balance
- convulsions
Infected pregnant women may experience only a mild, flu-like illness; however, infections during pregnancy can lead to miscarriage or stillbirth, premature delivery, or infection of the newborn.
Duration of Illness
- The illness usually resolves in 5 to 10 days.
Complications
- Infections during pregnancy can lead to miscarriage or stillbirth,
premature delivery, or infection of the newborn.
- Listeriosis
and Pregnancy: What is Your Risk?
U.S. Department of Agriculture; Provides information on safe food handling for a healthy pregnancy.
- Listeriosis
and Pregnancy: What is Your Risk?
Transmission
- The bacterium has been found in a variety of raw foods, such as uncooked
meats and vegetables.
- Processed foods may also become contaminated with Listeria after
processing, such as soft cheeses, hot dogs, and cold cuts or deli meats.
- Unpasteurized (raw) milk or foods made from unpasteurized milk may
contain the bacterium.
Do you suspect that you have a foodborne illness? Visit reporting suspected foodborne illnesses.

