A 2-year-old child is brought to the emergency with history offerer and vomiting. On examination he has neck rigidity. The CSF examination shows polymorphs more that 2000/m> I protein 100 mg/dl and glucose 10 mg/dl. The Gram stain shows the presence of Gram negative coccobacilli. The culture shows growth of bacteria only on chocolate agar and not on blood agar. The causative agent is

(B) Haemophilus influenzae. # Meningitis: This is the most serious disease produced by H. influenzae with case fatality rates up to 90 per cent in the untreated.> Bacilli reach the meninges from the nasopharynx through the bloodstream.> Disease is more common in children between two months and three years of age.> Age incidence has been correlated with the absence of bactericidal anti-PRP antibodies.> Older children develop immunity as a result of subclinical infection.> It has been reported that in the tropics, non-type b strains may be responsible for meningitis more often than in the temperate zcnes.