What are the main symptoms associated with Listeria monocytogenes infections?

Listeria monocytogenes infections primarily manifest through a set of symptoms that are indeed aligned with the selected answer. The most common initial symptoms include fever and muscle aches, which can sometimes escalate into more severe outcomes if the infection spreads to the nervous system. This can lead to symptoms such as meningitis, which is particularly concerning for vulnerable populations like pregnant women, newborns, and individuals with compromised immune systems.

In contrast, while options like diarrhea and cramps might be associated with other foodborne illnesses, they are not hallmark symptoms of a Listeria infection, as Listeria does not typically cause gastrointestinal distress in the way that some other pathogens do. The presence of nervous system effects in the correct answer highlights the unique and serious complications that can arise from Listeria infections, distinguishing them from other foodborne pathogens. The focus on systemic symptoms rather than gastrointestinal ones emphasizes the potential severity and progression of this particular infection, reinforcing the importance of recognizing and treating Listeria-related illness promptly.