Open Outbreak

Meningococcal disease

Also known as: Neisseria meningitidis, invasive meningococcal disease, IMD, meningococcal meningitis, meningococcal septicaemia

Meningococcal disease is a serious bacterial infection caused by Neisseria meningitidis. Many people carry this bacterium in the back of the nose or throat without becoming ill, but in some people it enters the bloodstream or tissues around the brain and spinal cord. When that happens, illness can worsen very quickly. It can cause meningitis, which is infection and swelling of the lining around the brain and spinal cord, or sepsis, a dangerous bloodstream infection. Spread is mainly through close contact with respiratory or throat secretions, so risk rises in crowded living conditions and mass gatherings. The incubation period is usually 2 to 10 days. Even with prompt treatment, WHO says the disease has a high case fatality rate, and survivors can have lasting problems. Vaccines are available against several major serogroups, including A, C, W, Y, and in some countries B. Treatment is with urgent antibiotics and hospital care. Large epidemics have been especially important in the African meningitis belt, but disease occurs worldwide.

Key facts

TransmissionPerson to person through close contact with respiratory or throat secretions; many people carry the bacteria in the nose or throat without symptoms.
IncubationUsually 2 to 10 days.
Case fatalityHigh despite prompt treatment according to WHO; one 2013 WHO African meningitis belt report gave a 9.3% case fatality ratio among suspected meningitis cases in that season. Untreated disease can be much more deadly, but precise overall untreated and treated figures were not established from the sources retrieved here.
Reproduction numberunknown
VaccineVaccines exist against serogroups A, C, W, and Y (quadrivalent MenACWY), and serogroup B vaccines are also available in some settings.
TreatmentUrgent hospital treatment with antibiotics; WHO notes prompt and appropriate treatment is needed, but fatal outcomes can still occur.
ReservoirHumans; the natural reservoir is the human nasopharyngeal mucosa.
Endemic regionsWorldwide, with the largest epidemic burden historically in the African meningitis belt.

Transmission

Meningococcal disease spreads from person to person through close contact with respiratory or throat secretions. In plain terms, that means the bacterium is usually passed during sustained close contact, such as living in the same household, kissing, or spending long periods in crowded indoor settings. It is not mainly a disease of casual passing contact. A key point is that many healthy people carry Neisseria meningitidis in the nose or throat without symptoms. The 2000 clinical review says the only natural reservoir is the human nasopharyngeal mucosa, and about 10% of people may carry meningococci, though this varies by age and setting. WHO’s 2025 report also highlights higher risk during mass gatherings such as Hajj and Umrah, where crowding and mixing of people from many regions can support transmission. The incubation period is usually 2 to 10 days.

Symptoms and severity

This illness is dangerous because it can become severe very fast. It can appear as meningitis, which affects the lining around the brain and spinal cord, or as septicaemia, a bloodstream infection, or both together. Early symptoms can be hard to tell apart from other infections, but the disease can progress quickly to shock, organ failure, or death. WHO describes invasive meningococcal disease as life threatening and linked to severe long-term complications. These may include neurological disability, hearing loss, or limb damage in survivors, although the exact mix varies from case to case. In the African meningitis belt, WHO reported 9,249 suspected meningitis cases and 857 deaths up to epidemiologic week 19 in 2013, a case fatality ratio of 9.3% for that season. That figure should not be treated as a global average, but it shows that fatal outcomes remain common even with surveillance and response.

Treatment and vaccines

Meningococcal disease needs urgent medical treatment in hospital. WHO says it remains a life-threatening infection with a high case fatality rate despite prompt and appropriate treatment, which underlines how important early care is. The sources retrieved here do not give one universal antibiotic regimen, but standard care is rapid antibiotics plus supportive hospital treatment. Prevention is stronger than treatment alone, because vaccines can stop many cases. A 2018 review describes meningococcal conjugate vaccines against serogroups A, C, W, and Y, and also notes vaccines against serogroup B. WHO’s 2025 report states that Saudi Arabia requires quadrivalent MenACWY vaccination for Hajj and Umrah travel, because it protects against serogroups A, C, W, and Y. The same WHO report noted low vaccination compliance among some 2025 Umrah travellers and recorded travel-associated cases. Vaccines do not cover every strain equally everywhere, so local vaccine policy depends on which serogroups are circulating.

Where it occurs

Meningococcal disease occurs worldwide, but the burden is not evenly spread. WHO says it can appear as sporadic cases, clusters, or epidemics, depending on the region and the circulating serogroups. The largest epidemic burden has long been in the African meningitis belt, where WHO has repeatedly published outbreak updates. These reports show that meningococcal epidemics have been a recurring public health problem across many countries in that belt. Outside Africa, cases also occur in Europe, the Americas, Asia, and the Middle East, usually as isolated cases or smaller outbreaks, though international spread can happen. WHO’s 2025 Disease Outbreak News item linked cases in several countries to recent Umrah travel in Saudi Arabia, showing how mass gatherings can connect outbreaks across borders. Crowding, low vaccine coverage, and limited access to care can increase the chance that local transmission will lead to larger outbreaks.

Recent history

In WHO’s Disease Outbreak News archive, meningococcal disease appears repeatedly, mainly in the African meningitis belt and in occasional travel-associated events. The tool results for this session returned WHO items from 2001, 2002, 2006, 2008, 2009, 2012, 2013, 2015, 2017, and 2025. That pattern suggests a disease that remains important but shifts by place, season, and serogroup. WHO’s 2017 notices on Nigeria and Togo stressed that MenA vaccine rollout reduced serogroup A disease, while other serogroups continued causing outbreaks. In 2025, WHO reported 17 travel-associated cases linked to Umrah in Saudi Arabia across several countries, with serogroup W135 identified in confirmed cases and some earlier pilgrimage-associated strains showing ciprofloxacin resistance. For this site’s own archive, the supplied metadata says there are 0 archived WHO notices since 1996 under the pathogen key and one site record: “Meningococcal disease outbreak in Kent, United Kingdom” marked closed.

What to watch

The main warning signs are changes that make spread, severity, or control worse. One is expansion into new regions or new settings, especially crowded settings such as dormitories, refugee camps, prisons, or mass gatherings. Another is a shift toward more sustained person-to-person spread from a particular serogroup, especially if it causes clusters across countries. WHO’s 2025 report also highlights poor vaccination uptake among travellers to Hajj and Umrah as a practical risk signal, because low coverage can open the way for international spread. A second important signal is drug resistance. WHO noted ciprofloxacin-resistant strains in some 2024 pilgrimage-associated cases, which matters because resistance can complicate preventive treatment for close contacts. A third is vaccine mismatch or supply problems: if the main circulating serogroup is not well covered by the vaccines being used, or if vaccine supply falls short during an outbreak, control becomes harder. Rapid rises in deaths or severe complications would also be concerning.

Updated