Because the immune system is suppressed during pregnancy, pregnant women are more likely to get Listeria than non-pregnant women; however, it is extremely unlikely (one in 50 million). Transmitted through bacteria in food, Listeria can cause severe infection, preterm labor and miscarriage. Symptoms may show up 2-30 days after exposure and include mild, flu-like symptoms—fever, nausea, vomiting, headaches, and muscle aches. A simple blood test can confirm listeriosis. The highest-risk foods are soft cheeses (i.e. brie, blue cheese, Mexican style, feta), deli meats, pâté, undercooked hot dogs, and raw fruits and vegetables that have been inadequately washed. Be sure to wash all vegetables, fruits and salads before cooking or eating.