Neisseria meningitidis is found in other parts of the world as well, but the highest rates occur in the "meningitis belt." Meningococcal disease is persistently high in this region. Large epidemics occur every 5–12 years, typically during the dry season (December–June). Incidence of the disease declines from May to June in the more humid weather. However, a monovalent serogroup A meningococcal conjugate vaccine (
MenAfriVac) was introduced in the region in 2010. Since then, meningococcal outbreaks in the meningitis belt have primarily been due to serogroups C and W. A few serogroup X outbreaks have also been reported. In the African meningitis belt, the WHO defines a meningococcal epidemic as at least 100 cases per 100,000 inhabitants in a year. At its peak, the incidence of meningococcal disease has reached rates of up to 1,000 cases per 100,000 inhabitants, such as during the epidemics of 1996 and 2000–2001. In the belt, fatality from NmA disease has been estimated at 10–15%, although higher rates have been seen in some settings. Around 10–20% of survivors of meningococcal meningitis are left with permanent neuropsychological conditions such as hearing loss, vision loss, epilepsy, or other neurological disorders. Young children are particularly vulnerable due to immaturity in their immune systems, which contributes to the disproportionate burden of the disease in Africa due to its young population. ==Meningitis vaccine==