A 4-year-old girl from Bhubaneswar was brought to the emergency room by her parents due to an acute onset of fever, neck rigidity, and altered sensorium for the past 2 days. Physical examination showed that when her neck was passively flexed, her legs also flexed (positive Brudzinski's sign). Direct examination of the CSF showed gram-positive, lanceolate-shaped diplococci surrounded by a halo.
a. What is your clinical diagnosis of this condition and the most likely etiologic agent?
b. How will you confirm the etiological agent in the laboratory?
