Which gram-negative bacterium is commonly associated with otitis media and conjunctivitis in young children?

• A. Staphylococcus aureus
• B. Haemophilus influenzae
• C. Neisseria gonorrhoeae
• D. Klebsiella pneumoniae

Answer: (B)

Haemophilus influenzae, particularly non-typeable strains, is a leading cause of both otitis media and conjunctivitis in young children. These non-typeable strains lack a capsule, live in the nasopharynx, and can ascend to the middle ear or spread to the conjunctiva, causing mucosal infections common in kids. The organism is gram-negative and appears as a small coccobacillus on Gram stain. The Hib vaccine targets encapsulated type b strains that cause invasive diseases like meningitis, but it doesn’t cover these non-typeable strains, so mucosal infections remain frequent. In contrast, the other bacteria listed are either gram-positive or less typically associated with the combination of otitis media and conjunctivitis in this age group.