A 9 years old child presented to OPD with complaints of high grade fever, vomiting, one episode of seizure. CSF examination was done and Gram staining of the culture showed lanceolate shaped gram positive diplococci. What is the probable causative agent?

In the given gram stain, diplococcus arrangement is shown which is characteristic feature of pneumococcus or Streptococcus pneumoniae which causes conjunctivitis, otitis media, meningitis, pneumonia and sinusitis. Streptococcus pneumoniae is the most common cause of meningitis in adults. Streptococcus pneumoniae is responsible for 10-20 percent of meningitis cases in children ages 1 month to 15 years. Neisseria meningitidis range from 25-40 percent. Group A and B Streptococci appear to be involved only 2-4 percent of the time. Under the conditions described above (CSF showing gram positive diplococcic), Streptococcus pneumoniae would be the most likely etiologic agent.