In a 6-day-old infant suspected of herpes simplex meningitis, what cerebrospinal fluid (CSF) findings are anticipated?

In a 6-day-old infant suspected of herpes simplex meningitis, the most anticipated cerebrospinal fluid (CSF) findings include elevated white blood cells (WBCs), normal glucose levels, and elevated protein levels. While option A mentions elevated RBCs, it is important to note that the definitive laboratory markers for a viral infection like herpes simplex, which commonly affects neonates, are elevated WBC counts, particularly lymphocytes.

Typically, in viral meningitis, you would see a pleocytosis (increased WBCs) with a lymphocytic predominance, an elevated protein concentration, and normal glucose levels in the CSF. The normal glucose is because, unlike bacterial infections, the metabolism and utilization of glucose by viral pathogens do not lead to significant decreases in glucose levels in the CSF.

Elevated RBCs could suggest a traumatic tap or hemorrhagic process rather than an infection like meningitis, which specifically involves clear CSF with alterations in cell count and protein levels but generally not a significant increase in red blood cells unless there was an extraneous factor involved.

Thus, in true cases of herpes simplex meningitis, one would expect findings of elevated WBCs with a predominance of lymphocytes, normal glucose levels