More than 2.5 million people worldwide were infected with meningitis in 2023, according to a comprehensive global assessment published late last week in The Lancet Neurology. More than 250,000 people died from the condition, an infection that causes inflammation of the meninges, the fluid and membranes around the brain and spinal cord. 

Meningitis, which causes symptoms such as headache, fever and a stiff neck, has a mortality rate of about 18%.

One-third of the people who die from meningitis are children under age 5, according to the report, which is based on the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2023 framework. The GBD is a systematic, scientific effort aimed at measuring the comparative burden caused by diseases, injuries, and risk factors across age-groups, sexes, and locations over time.

The top risk factors for dying from meningitis are low birthweight, pre-term birth, and household air pollution, according to the report. Low-income countries in the African “meningitis belt,” which includes Nigeria, Chad, and Niger, have recorded the highest death and infection rates. 

Three sources of bacterial meningitis—Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae—can be prevented with vaccines.

Infection with another cause of meningitis—a bacterium called group B Streptococcus, which can pass from mother to child during delivery—can be prevented by screening pregnant women for the bacterium and administering intravenous antibiotics to moms during labor.

Although these interventions have helped to lower the incidence and mortality of meningitis since 1990, preventable cases of meningitis sickened 594,000 people in 2023 and killed 98,700. The study authors wrote that countries need to expand disease surveillance, vaccination, and maternal screening to prevent more suffering and death.

“Targeted investment in WHO pillars, including expanded vaccination coverage, new vaccine development, antibiotic stewardship, region-specific outbreak preparedness, and advances in treatment access and equity, could help to prevent disability and mortality caused by meningitis,” they wrote.

Meningitis is the leading infectious cause of neurologic disabilities worldwide, according to the study. Although most people recover fully, survivors can be left with learning and intellectual disabilities such as memory loss, lack of concentration or issues with thinking and problem solving. 

Other after-effects include clumsiness and co-ordination problems; headaches; deafness, hearing problems, tinnitus, dizziness or loss of balance; epilepsy or seizures; weakness, paralysis or spasms; speech problems; loss of sight or vision problems; hydrocephalus, or fluid on the brain; mental health issues and changes to personality or behavior; sleep problems; fatigue; and anxiety and depression.

The study was funded by the Gates Foundation, the Wellcome Trust, and the UK Department of Health and Social Care.