Meningitis is an infectious disease of the central nervous system that is caused by diffuse inflammatory changes in the soft meninges and arachnoid membranes of the central nervous system due to invasion by pathogenic microorganisms. Common pathogenic microorganisms in meningitis include viruses, bacteria, fungi, spirochetes, parasites, rickettsiae and prions. Common clinical manifestations include headache, fever, vomiting, positive meningeal irritation signs, and laboratory tests reveal increased cerebrospinal fluid pressure, increased cell count and biochemical abnormalities. There are three main routes of infection for meningitis: 1. Bloodstream infection: pathogens enter the bloodstream through animal bites that damage the skin mucosa, or pathogens present in other parts of the body, and when the body’s resistance is reduced, the germs enter the bloodstream to form bacteremia, and bacteria enter the skull via the bloodstream to cause meningitis; 2. Direct diffusion: direct invasion of the skull by foci of infection from neighboring sites (e.g., sinusitis, otitis media, mastoiditis, brain abscess, craniocerebral trauma, cranial osteomyelitis, etc.); 3. Trans-cerebrospinal fluid pathway: through lumbar puncture or craniocerebral surgery, pathogenic bacteria enter the cerebrospinal fluid and directly cause meningeal infection. In addition to the above infection pathways, there are also gastrointestinal pathway infections, such as viral meningitis caused by enterovirus infection, and a few can be infectious through respiratory tract infections, such as epidemic meningomyelitis. Due to the different pathogenic bacteria of meningitis, the early clinical manifestations vary and can lead to death or serious sequelae in severe cases, but most of them can be cured if treated early and actively.