Listeria monocytogenes Infection (cont.)
Listeriosis Symptoms and Signs
The symptoms and signs of listeriosis can vary widely, and the clinical
presentation often depends largely on the underlying state of health and age of
the affected individual. Most healthy individuals who become infected with
Listeria monocytogenes experience no symptoms at all, though rarely some may
develop a mild self-limiting gastrointestinal illness. However, it is the
high-risk patient populations who generally go on to develop the more severe
form of the disease. There can be a substantial delay between the time of
exposure to Listeria monocytogenes and the development of symptoms (the
incubation period), varying anywhere from several days to two to three months.
- Diarrhea, nausea, vomiting, fever, and muscle aches are common symptoms
associated with listeriosis. Often, these symptoms will resolve spontaneously
after seven to 10 days.
- If the infection spreads to the central nervous system, individuals may
experience headache, stiff neck, confusion, loss of balance, or
symptoms may be seen with meningitis, encephalitis, or brain abscess.
- Infected pregnant women may experience symptoms of a mild
However, the unborn child is at risk of miscarriage, stillbirth, premature
delivery, or sometimes a life-threatening infection after birth (pneumonia,
sepsis and meningitis, for example).
- Listeriosis during pregnancy usually occurs during the third trimester.
- In the United States, approximately 27% of all cases of listeriosis occur
in pregnant women.
- Rarely, infection with Listeria monocytogenes can lead to localized
infections of the skin, heart, joint, or bone.
- Death from listeriosis generally occurs from a disseminated infection in
the high-risk individuals.