Clinical Laboratory Science Practice Exam 2026 – Your All-in-One Guide to Exam Success!

Viral meningitis is most likely when CSF shows increased protein with normal glucose and normal lactate, along with a lymphocytic predominance. This pattern reflects meningeal inflammation driven by a viral infection without the metabolic shifts typical of bacteria. In bacterial meningitis, glucose is usually decreased and lactate is increased due to bacterial metabolism and neutrophilic response. Fungal and tubercular meningitis often present with very low glucose and markedly elevated protein, with lymphocytic pleocytosis and often higher lactate. So the combination of elevated protein, normal glucose, normal lactate, and increased lymphocytes most strongly points to viral meningitis.