<unk>  describes infections caused by the bacterium Neisseria meningitidis (also termed meningococcus). It has a high mortality rate if untreated but is vaccine-preventable. While best known as a cause of meningitis, it can also result in sepsis, which is an even more damaging and dangerous condition. Meningitis and meningococcemia are major causes of illness, death, and disability in both developed and under-developed countries. There are approximately 2,600 cases of bacterial meningitis per year in the United States, and on average 333,000 cases in developing countries. The case fatality rate ranges between 10 and 20 percent. The incidence of endemic<unk>  during the last 13 years ranges from 1 to 5 per 100,000 in developed countries, and from 10 to 25 per 100,000 in developing countries. During epidemics the incidence of<unk>  approaches 100 per 100,000.<unk>  vaccines have sharply reduced the incidence of the disease in developed countries. The disease's pathogenesis is not fully understood. Neisseria meningitidis colonises a substantial proportion of the general population harmlessly, but in a very small percentage of individuals it can invade the bloodstream, affecting the entire body, most notably limbs and brain, causing serious illness. Over the past few years, experts have made an intensive effort to understand specific aspects of<unk>  biology and host interactions; however, the development of improved treatments and effective vaccines is expected to depend on novel efforts by workers in many different fields. While<unk>  is not as contagious as the common cold (which is spread through casual contact), it can be transmitted through saliva and occasionally through close, prolonged general contact with an infected person.
Meningococcal disease
Disseminated disease
Postvaccinal encephalitis
Meningeal syphilis
Leukomyelitis
Herpesviral meningitis
Granulomatous meningoencephalitis
Fungal meningitis