Meningococcal meningitis is a purulent meningitis caused by Neisseria meningitis (Nm). The pathogenic bacteria invade the blood circulation from the nasopharynx and are finally confined to the meninges and spinal cord membranes, forming purulent meningeal lesions. The main clinical manifestations are sudden fever, headache, vomiting, ecchymosis, petechiae on the skin, and stiff neck and other meningeal irritation signs. The cerebrospinal fluid shows purulent changes. In addition, meningococci may not invade the meninges but only show sepsis, and severe cases may present an fulminant attack. Infection can also occur in the upper and lower respiratory tract, joints, pericardium, eyes and other parts. This disease is found in countries around the world, presenting as sporadic or large or small epidemics, with the highest incidence in children.