Listeria infection is best described as which of the following?

• A. A bacterial infection that can be passed to the fetus and causes flu-like symptoms.
• B. A virus transmitted through air.
• C. A fungus causing skin irritation.
• D. A parasite causing intestinal obstruction.

Answer: (A)

Listeria infection is a bacterial infection that can be passed from a pregnant person to the fetus, and it often presents with flu-like symptoms in the mother. Listeria monocytogenes is a bacterium that has the ability to cross the placenta, which can lead to fetal loss or severe neonatal disease such as sepsis or meningitis. In many cases, pregnant individuals experience nonspecific symptoms like fever and malaise, sometimes with gastrointestinal upset, rather than a dramatic illness. This combination—bacterial origin, vertical transmission to the fetus, and maternal flu-like illness—distinguishes it from viral, fungal, or parasitic infections.