haemophilus meningitis (MONDO_0000889) is infections of the nervous system caused by bacteria of the genus haemophilus, and marked by prominent inflammation of the meninges. haemophilus influenzae type B is the most common causative organism. The condition primarily affects children under 6 years of age but may occur in adults. Also known as: Haemophilus influenzae bacterial meningitis, Haemophilus influenzae caused bacterial meningitis.