Q: What are the causative organisms of bacterial meningitis?

Haemophilus influenzae, which used to be the most common cause of the disease in infants and young children before the HiB vaccine was introduced.

Listeria monocytogenes can infect people of any age, but pregnant women, very young children, and the elderly are at most risk. L. monocytogenes can be acquired through contaminated foods.

Neisseria meningitidis is highly contagious and causes meningococcal meningitis. This form is commonly found in children and young adults, including college students living in dorms.

Staphylococcus aureus may present itself after head trauma or brain surgery

Streptococcus pneumoniae, the most common cause of bacterial meningitis in children, may appear along with pneumonia, an ear infection, or a sinus infection