Final answer:
Haemophilus influenzae is a notable cause of bacterial meningitis, particularly in young children, not influenza. The introduction of the Hib vaccine has significantly reduced its incidence. H. influenzae also causes pneumonia, especially in the elderly.
Step-by-step explanation:
Haemophilus influenzae is a significant cause of bacterial meningitis, particularly in young children. The H. influenzae serotype b (Hib) strain, once a common cause of meningitis in children, has become much less prevalent due to the widespread use of the effective Hib vaccine. Despite its name, H. influenzae does not cause influenza; that is a viral illness.
The pathogen is also known to cause pneumonia, mainly in the elderly, through nonencapsulated strains. However, when it comes to meningitis, encapsulated strains, particularly the Hib, were historically a leading cause. Hib meningitis can result in high intracranial pressure, leading to complications such as deafness or brain damage in survivors, despite a decrease in incidence due to vaccinations.
To prevent H. influenzae infections, including meningitis, vaccination with the Hib polysaccharide conjugate vaccine is highly recommended for all children at specific intervals during infancy and the toddler years.