A 22 year old male military recruit complains of a headache and stiff neck. He is examined, blood is drawn, and a lumbar puncture performed. The glucose in the CSF is 100 mg/dL and the serum glucose is 120 mg/dL. The CSF shows 3 lymphocytes and 0 neutrophils/microliter. Which of the following conclusions concerning the interpretation of these findings is most accurate?

Both the CSF glucose level and the small number of lymphocytes present are within normal limits. It is normal for the CSF glucose to be less than serum glucose, often about 2/3 of the serum value. Bacterial meningitis can profoundly lower CSF glucose levels. CSF from bacterial meningitis cases also usually shows large numbers of neutrophils. Viral meningitis will not alter the CSF glucose level, but the CSF often contains many lymphocytes. Ref: Brooks G.F. (2013). Chapter 48. Cases and Clinical Correlations. In G.F. Brooks (Ed), Jawetz, Melnick, & Adelberg's Medical Microbiology, 26e.