Which CSF finding supports a diagnosis of meningococcal meningitis in the described case?

Which CSF finding supports a diagnosis of meningococcal meningitis in the described case?

• A. Clear CSF with normal WBC
• B. Cloudy CSF with increased WBC and low glucose
• C. Clear CSF with high glucose
• D. Pink-tinged CSF with positive gram-positive diplococci

Answer: (B)

Bacterial meningitis, including meningococcal meningitis, typically presents with a purulent CSF due to a strong neutrophilic inflammatory response, high protein, and low glucose because bacteria consume glucose and disrupt normal transport. The described CSF—cloudy or turbid with an increased white blood cell count and low glucose—fits this pattern best, signaling bacterial meningitis rather than a viral process. In meningococcal cases, you’d also expect to see Gram-negative diplococci on staining, which helps confirm the organism. The other scenarios don’t match this bacterial profile: clear CSF with normal WBC argues against meningitis, and clear CSF with high glucose also argues against bacterial infection; a pink-tinged CSF with Gram-positive diplococci would point to a different organism, such as Streptococcus pneumoniae.

Bacterial meningitis, including meningococcal meningitis, typically presents with a purulent CSF due to a strong neutrophilic inflammatory response, high protein, and low glucose because bacteria consume glucose and disrupt normal transport. The described CSF—cloudy or turbid with an increased white blood cell count and low glucose—fits this pattern best, signaling bacterial meningitis rather than a viral process. In meningococcal cases, you’d also expect to see Gram-negative diplococci on staining, which helps confirm the organism. The other scenarios don’t match this bacterial profile: clear CSF with normal WBC argues against meningitis, and clear CSF with high glucose also argues against bacterial infection; a pink-tinged CSF with Gram-positive diplococci would point to a different organism, such as Streptococcus pneumoniae.