The Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) are investigating a multistate outbreak of listeria monocytogenes infections connected to Fresh Express salads, the agency announced on Dec. 21. Listeria monocytogenes is a food-borne illness that can cause short-term symptoms like high fever, severe headache, stiffness, nausea, abdominal pain, and diarrhea, as per the CDC. While it is generally rare and causes a mild infection in healthy individuals, it primarily affects young children, the elderly, or those with weakened immune systems, as well as pregnant women. In pregnant women, it can potentially cause serious problems such as miscarriages and stillbirths and cause severe disease in the fetus or newborn baby. In adults aged 65 and older and those with weakened immune systems, listeria monocytogenes can in some cases cause severe infections in the bloodstream, such as sepsis, or in the brain, which can cause meningitis or encephalitis. An estimated 1,600 people get listeriosis each year, …