If you have symptoms such as fever or stiff neck, consult your doctor. During pregnancy, a blood test is the most reliable way to find out if your symptoms are due to listeriosis. Newborns rather than the pregnant women themselves suffer the serious effects of infection in pregnancy. Persons with weakened immune systems. Healthy adults and children occasionally get infected with Listeria, but they rarely become seriously ill.
Listeria is found in soil and water.
Vegetables can become contaminated from the soil or from manure used as fertilizer. Animals can carry the bacterium without appearing ill and can contaminate foods of animal origin such as meats and dairy products. The bacterium has been found in a variety of raw foods, such as uncooked meats and vegetables, as well as in processed foods that become contaminated after processing, such as soft cheeses and cold cuts at the deli counter. A person with listeriosis usually has fever, muscle aches, and sometimes gastrointestinal symptoms such as nausea or diarrhea. If infection spreads to the nervous system, symptoms such as headache, stiff neck, confusion, loss of balance, or convulsions can occur.