Recognizing Listeria symptoms may be difficult because a wide range of symptoms can be associated with the illness. The most common early manifestations of the illness are flu-like symptoms, including fever and muscle aches. Gastrointestinal symptoms such as nausea and diarrhea may accompany the flu-like symptoms, or may occur on their own. The symptoms of Listeria poisoning (listeriosis) include:
Flu-like fever and muscle aches
Upset stomach or diarrhea
Stiff neck, headache, loss of balance, confusion or convulsions
The average length of time between eating food contaminated with this deadly pathogen and the onset of symptoms is three weeks. If you or a member of your family in an at-risk group (young children, pregnant women, the elderly, and those with depressed immune systems) is experiencing symptoms you may want to consult a physician. Because listeriosis can be treated with antibiotics, it is important to recognize an infection at an early stage.
If a Listeria infection spreads to the nervous system it may result in meningitis. A person with an infection may experience a stiff neck, headache, vertigo, confusion or convulsions. Meningitis is a life-threatening illness, and medical attention should be sought immediately. Learn more about meningitis.
Even if a pregnant woman infected with L. monocytogenes only experiences mild flu-like systems, the infection can result in serious complications for the pregnancy. Complications from an infection may result in premature delivery, stillbirth, miscarriage, or infection of the newborn.Learn more about listeriosis and pregnancy.