In healthy adults, infection with listeria can cause a short-lived flulike illness. Scientists now believe there may be link between listeria infection and miscarriages and stillbirths. Babies born to mothers infected during pregnancy can have trouble breathing, low body temperature, and other problems. Some who seem healthy at birth can have symptoms weeks later, such as feeding problems and fever. The organism can also be dangerous to small children, the elderly, and people with weakened immune systems.
Symptoms usually develop several weeks after exposure to the bacteria.
They sometimes, but not always, include fever, chills, muscle aches, and back pain. The incubation period before the illness develops can be as long as ten weeks, which can make it hard to pinpoint exactly which food made you sick. Doctors diagnose a fever or flulike illness as listeria infection by swabbing a sample from your vagina and cervix and checking your blood. Antibiotics will treat the infection. Newborns can also be tested and treated.