Meningococcal Meningitis

Unique identifier / Notation

BI0222

Synonyms

Meningitis Neisseria meningitis meningococcal cerebrospinal fever epidemic meningitis

Meningococcal meningitis is a bacterial form of meningitis, a serious infection of the thin lining that surrounds the brain and spinal cord, that is caused by the bacterium Neisseria meningitidis. Meningococcal meningitis has the potential to cause large-scale epidemics and is observed worldwide (adapted from WHO, 2025).

Primary reference(s)

WHO, 2025. Meningitis. World Health Organization (WHO). Accessed 25 May 2025.

Annotations

Additional scientific description

Meningococcal meningitis is a bacterial form of meningitis. Of the twelve types of Neisseria meningitidis, called serogroups, six (A, B, C, W, X, Y) can cause epidemics. The bacteria can be carried in the nasopharyngeal tract without causing symptoms and are transmitted through droplets of respiratory or throat secretions upon close and prolonged contact. It is believed that 1% to 10% of the population are asymptomatic carriers (WHO, 2025).

The average incubation period is four days but can range from two to ten days. The most common symptoms are a stiff neck, high fever, sensitivity to light, confusion, headaches and vomiting. Some cases may develop haemorrhagic rash. Meningococcal meningitis can kill in hours and if untreated, is fatal in 50% of cases. It may result in brain damage, hearing loss or disability in 10% to 20% of survivors (WHO, 2025).

Diagnosis of meningococcal meningitis relies on lumbar puncture showing a purulent spinal fluid. The bacteria can sometimes be seen in microscopic examinations of the spinal fluid. Diagnosis is confirmed by growing the bacteria from specimens of spinal fluid or blood or by polymerase chain reaction (PCR). Identification of the serogroups and susceptibility testing to antibiotics are important to define control measures (WHO, 2025).

The African meningitis belt is an area of increased risk of invasive meningococcal disease that stretches across Africa from Senegal and The Gambia on the western coast to Ethiopia and neighbouring countries in the east. The meningitis belt is characterized by a very high burden of disease, distinct seasonal patterns, pluri-annual cycles of outbreaks and local geographic variation in incidence. Outbreaks in the meningitis belt typically begin during the dry season, rapidly building up to a peak and subsiding abruptly with the start of the rainy season. Serogroup A was responsible for causing the majority of cases in the meningitis belt during annual epidemics of meningococcal disease from early in the twentieth century until recently, leading to tens of thousands of cases and thousands of deaths (WHO, 2020).

Surveillance, from case detection to investigation and laboratory confirmation is essential to the control of meningococcal meningitis. The World Health Organization (WHO) has published recommendations on types of surveillance and case definitions for vaccine preventable diseases (WHO, 2018)

Metrics and numeric limits

In 2019, there were an estimated 236 000 deaths (95% uncertainty interval [UI] 204 000-277 000) and 2·51 million (2·11-2·99) incident cases due to meningitis globally. The burden was greatest in children younger than 5 years, with 112 000 deaths (87 400-145 000) and 1·28 million incident cases (0·947-1·71) in 2019 (GBD, 2023).

Key relevant UN convention / multilateral treaty

International Health Regulations (2005), 3rd ed. (WHO, 2016).

Drivers

The geographic distribution and epidemic potential differ according to the serogroup of Neisseria meningitidis. There are no reliable estimates of global meningococcal disease burden due to inadequate surveillance in several parts of the world. During the dry season between December to June, dust winds, cold nights and upper respiratory tract infections combine to damage the nasopharyngeal mucosa, increasing the risk of meningococcal disease (WHO, 2025).

Higher risk is seen when people are living in close proximity, for example at mass gatherings, in refugee camps, in overcrowded households or in student, military and other occupational settings. Immune deficiencies such as HIV infection or complement deficiency, immunosuppression, and active or passive smoking can also raise the risk of different types of meningitis (WHO, 2025).

Meningococcal meningitis outbreaks occur more frequently under special risk conditions, such as crowded settings where people are in close proximity, mining areas, mass gatherings, such as religious or sporting events, settings with refugees or displaced persons, closed institutions, military camps and areas with high migration, such as high-traffic markets and border areas (WHO, 2025). Immunocompromised and/or people living with HIV are at increased risk of different types of meningitis (WHO, 2025).

Meningococcus is transmitted by aerosol or direct contact with respiratory secretions of patients or healthy human carriers. As a rule, endemic disease occurs primarily in children and adolescents, with highest attack rates in infants aged 3-12 months, whereas in epidemics older children and young adults may be more involved. Nasopharyngeal carriage of meningococci is most common among adolescents and young adults, less so among young children and relatively rare in adult populations.

Impacts

Transient nasopharyngeal carriage rather than disease is the normal outcome of meningococcal colonization. However, the rapid progression of meningococcal disease frequently results in death within 1-2 days after onset. 5-15% of children and young adults carry meningococci in the nose and throat, so chemoprophylaxis is of little value for the control of most endemic and epidemic disease. Immunization is the only rational approach to the control of meningococcal disease (WHO, 2024).

Globally, the highest burden of disease is seen in a region of sub-Saharan Africa, known as the African meningitis belt, which stretches from Senegal to Ethiopia, and is at high risk of recurrent epidemics of meningococcal meningitis (WHO, 2025).

Multi-hazard context

Globally, the highest burden of disease is seen in a region of sub-Saharan Africa, known as the African meningitis belt, which stretches from Senegal to Ethiopia, and is at high risk of recurrent epidemics of meningococcal meningitis (WHO, 2025)

Meningococcal meningitis outbreaks occur more frequently under special risk conditions, such as crowded settings where people are in close proximity, mining areas, mass gatherings, such as religious or sporting events, settings with refugees or displaced persons, closed institutions, military camps and areas with high migration, such as high-traffic markets and border areas (WHO, 2025).

Immunocompromised and/or people living with HIV are at increased risk of different types of meningitis (WHO, 2025).

Risk Management

As a rule, endemic disease occurs primarily in children and adolescents, with highest attack rates in infants aged 3-12 months, whereas in epidemics older children and young adults may be more involved. Nasopharyngeal carriage of meningococci is most common among adolescents and young adults, less so among young children and relatively rare in adult populations. Transient nasopharyngeal carriage rather than disease is the normal outcome of meningococcal colonization. However, the rapid progression of meningococcal disease frequently results in death within 1-2 days after onset. 5-15% of children and young adults carry meningococci in the nose and throat, so chemoprophylaxis is of little value for the control of most endemic and epidemic disease. Immunization is the only rational approach to the control of meningococcal disease (WHO, no date).

Licensed vaccines against meningococcal disease have been available for more than 40 years, but to date no universal vaccine against meningococcal disease exists. Vaccines are serogroup specific and confer varying degrees of duration and protection. They are used for prevention (routine immunisation) and in response to outbreaks (prompt reactive vaccination) In the African meningitis belt, meningococcus serogroup A accounted for 80–85% of meningitis epidemics before the introduction of a meningococcal A conjugate vaccine through mass preventive campaigns (since 2010) and into routine immunization programmes (since 2016). Continuing introduction into routine immunization programmes and maintaining high coverage is critical to avoid the resurgence of epidemics (WHO, 2025).

Antibiotics for close contacts of those with meningococcal disease, when given promptly, decreases the risk of transmission. Outside the African meningitis belt, chemoprophylaxis is recommended for close contacts within the household. Within the meningitis belt, chemoprophylaxis for close contacts is recommended in non-epidemic situations. Ciprofloxacin is the antibiotic of choice, and ceftriaxone an alternative (WHO, 2025).

The global roadmap Defeating Meningitis by 2030 was developed by WHO with the support of many partners. The strategy was approved in the first ever resolution on meningitis by the World Health Assembly in 2020 and endorsed unanimously by WHO member states. The roadmap sets a comprehensive vision “Towards a world free of meningitis” and has 3 visionary goals, including elimination of bacterial meningitis epidemics, reduction of cases of vaccine-preventable bacterial meningitis by 50% and deaths by 70%; and reduction of disability and improvement of quality of life after meningitis due to any cause (WHO, 2021a; 2025).

WHO is working on the Draft Intersectoral global action plan on epilepsy and other neurological disorders 2022 in consultation with Member States to address many challenges and gaps in providing care and services for people with epilepsy and other neurological disorders that exist worldwide (WHO, 2022).

Monitoring

Surveillance, from case detection to investigation and laboratory confirmation, is essential to the control of meningitis (WHO, 2025). Main objectives include:

detect and confirm outbreaks;
monitor the incidence trends, including the distribution and evolution of serogroups and serotypes;
estimate the disease burden;
monitor the antibiotic resistance profile;
monitor the circulation, distribution, and evolution of specific strains (clones); and
estimate the impact of meningitis control strategies, particularly preventive vaccination programmes (WHO, 2025).

WHO supports countries to conduct all-hazards strategic risk assessment in the contexts of health emergencies and disasters, which results in the development of a country risk profile. Empowered with the country risk profile, inclusive of a seasonal risk calendar, countries can anticipate potential emergencies before they occur to trigger early alerts and inform early actions (WHO, 2021b).

WHO's Early Warning, Alert and Response System (EWARS) has been designed to improve disease outbreak detection in emergency settings, such as in countries in conflict or following a disaster from natural hazards. It is a simple and cost-effective way to rapidly set up a disease surveillance system. EWARS is deployed during an emergency as an adjunct to the national disease surveillance system. WHO works with Ministries of Health and health sector partners to train local health workers to use the system. After the emergency, EWARS should re-integrate back into the national system (WHO, 2023).