Listeria (listeriosis): Symptoms and treatment
Listeria is a bacteria that can cause an illness called listeriosis. If you eat foods contaminated with Listeria, you can become infected and develop listeriosis.
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Symptoms of listeriosis
Listeriosis has a wide range of symptoms that vary depending on the person infected and the type of infection. Listeria can cause 2 types of infection: invasive and intestinal (non-invasive) listeriosis.
Invasive listeriosis
Symptoms of invasive listeriosis typically appear within 2 weeks, but may appear up to 3 months after exposure to Listeria. This kind of infection:
- often requires hospital care
- may lead to long-lasting health effects, brain infection, blood poisoning and can be fatal
If you are pregnant, symptoms include:
- fever
- chills
- fatigue
- headache
- muscle aches
- diarrhea (watery, non-bloody)
If you aren't pregnant, but have a weakened immune system or are older than 60, symptoms include:
- fever
- chills
- fatigue
- seizures
- stiff neck
- confusion
- muscle aches
- intense headache
- loss of balance and coordination
- tremor (trembling or involuntary shaking)
Intestinal (non-invasive) listeriosis
Symptoms of intestinal listeriosis can start within 24 hours after eating contaminated food, and typically last no more than a week. The symptoms are:
- fever
- nausea
- vomiting
- joint pain
- headache
- muscle aches
- diarrhea (watery, non-bloody)
This illness is usually mild and most people recover completely on their own. Some people may not get sick at all. However, some people with intestinal illness may develop invasive illness.
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If you become ill
If you think you have listeriosis, contact your health care provider. This is especially important if you're at higher risk of complications. Let your health care provider know if you think you ate any foods linked to a recall or an outbreak.
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Diagnosing listeriosis
A health care provider can order appropriate tests for Listeria.
Invasive listeriosis is diagnosed through laboratory testing that detects Listeria in body fluids or tissues such as:
- blood
- placenta
- cerebrospinal fluid
Intestinal listeriosis is rarely diagnosed because people with no symptoms or only symptoms of intestinal illness with no risk factors for severe illness often aren't tested for listeriosis.
Treating listeriosis
If you have symptoms of listeriosis, seek health care provider assessment and care, especially if your risk of severe illness is high. Invasive listeriosis can be treated with antibiotics.
If you have intestinal listeriosis, you may develop invasive listeriosis. It's important to monitor symptoms and contact your health care provider if symptoms get worse.
Most people with intestinal listeriosis recover on their own and don't experience any long-term health effects. As vomiting and diarrhea can lead to dehydration (loss of fluids), you can benefit from drinking extra fluids while you have these symptoms.