Symptoms of Listeria Food Poisoning, or Listeriosis
Initial symptoms may include fever, muscle aches, fatigue, and sometimes gastrointestinal symptoms, such as nausea, vomiting, or diarrhea. If the infection spreads to the nervous system, symptoms may include headache,stiff neck, confusion, loss of balance, or convulsions.
Infected pregnant women may experience only mild flu-like symptoms; however, infections during pregnancy can lead to miscarriage, premature delivery, stillbirth, or septicemia (blood infection) or meningitis in the newborn.
According to the FDA, onset time of serious forms of listeriosis is unknown but may range from a few days to three weeks. The onset time of gastrointestinal symptoms is unknown but is probably greater than 12 hours.