Listeriosis can cause fever, muscle aches, headache, stiff neck, confusion, loss of balance, and convulsions sometimes preceded by diarrhea or other gastrointestinal symptoms. In pregnant women, the infection can cause miscarriages, stillbirths, premature delivery, or life-threatening infection of the newborn. In addition, serious and sometimes fatal infections can occur in older adults and persons with weakened immune systems. Listeriosis is treated with antibiotics. Persons in the higher-risk categories who experience flu-like symptoms within two months after eating contaminated food should seek medical care and tell the health care provider about eating the contaminated food.