Meningitis can be caused by several species of bacteria, viruses, fungi, and parasites. The most common causes of bacterial meningitis are Neisseria meningitidis (meningococcus), Streptococcus pneumoniae (pneumococcus), Haemophilus influenzae, and Streptococcus agalactiae (group B streptococcus)
. Viral meningitis is usually caused by enteroviruses, mumps virus, and herpes simplex virus, among others
. Fungal and parasitic meningitis are rare, but they can be caused by fungi such as Cryptococcus and parasites like Amoeba
. Other causes of meningitis include injuries, cancers, certain drugs, and noninfectious factors such as chemical reactions, drug allergies, and some types of cancer
. It's important to note that vaccines are available to help protect against some kinds of bacterial and viral meningitis
