Diagnosis
Read more about how the clinical presentation of IMD varies in different age groups
Epidemiology of invasive meningococcal disease (IMD)
IMD is rare but serious
In England, in 2024/25:
2
| Number of confirmed cases | 378 |
|---|---|
| Case fatality rate | 8.2% (31/378) |
| Dominant serogroup | MenB (82.6% of cases) |
| Current incidence | <1 per 100,000 people per year |
The first and highest incidence peak of IMD occurs in infants less than 1 year old1
In England, in 2024/25, serogroup B (MenB) was the predominant cause of IMD across all age groups, and accounted for 90% of IMD cases in infants and 87% of cases in 1-to-4 year olds.2 The remaining cases were caused by serogroups W, Y C, and E, and a small number of ungrouped or ungroupable strains.2 Several MenW cases were associated with recent travel to the Middle East.2
Another, smaller incidence peak of IMD occurs in adolescents and young adults between 11 and 24 years old1-3
Social behaviours, including living in university halls of residence, visiting bars and smoking may drive the secondary peak in this age group.4 In England, in 2024/25, MenB accounted for 100% of IMD cases in 15-to-19 year olds and 97% of cases in 20-to-24 year olds.2
Incidence of IMD has been on the decline
The incidence of IMD in the UK has decreased in all age groups since the implementation of meningococcal vaccines into the UK national immunisation schedule in 1999.1 Further declines were also seen during the COVID-19 pandemic due to national lockdowns, restrictions and physical distancing measures.1
Since July 2021, overall IMD case numbers have started to return to pre-pandemic levels, and are mainly driven by MenB.2
IMD cases in England
Incidence of IMD in England: 2012/13 through to 2024/25
Figure adapted from the UK Health Security Agency. Invasive meningococcal disease in England: annual laboratory confirmed reports for epidemiological year 2024 to 2025.
IMD cases by serogroup and year
Cases of IMD by serogroup and epidemiological year (England and Wales)
Figure adapted from the UK Health Security Agency. Meningococcal: The Green Book, chapter 22 (June 2025)
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IMD cases by age group and year
Cases of IMD by age group and epidemiological year (England and Wales)
Figure adapted from the UK Health Security Agency. Meningococcal: The Green Book, chapter 22 (June 2025).
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Despite the low number of cases, IMD has a devastating impact
IMD is a potentially fatal condition requiring urgent recognition and treatment
Around 5–10% of cases of IMD are fatal, even with early diagnosis and treatment; this increases to 50% when left untreated.1, 5 In England, the provisional IMD case fatality ratio was 8.2% in 2024/25.2
IMD can cause life-changing complications
The frequency of complications depends on how IMD manifests. While complications may develop in 7% of people with meningococcal meningitis, up to 57% of people with meningococcal septicaemia may experience sequelae.6 Long-term complications include hearing loss, severe visual impairment, communication problems, limb amputation(s), seizures and brain damage.1
The societal burden per IMD case is high
Globally, up to 20% of IMD survivors experience long-term sequalae.7 Mean inpatient costs may be 5× higher in patients who develop complications than in those who do not.7
References
- UK Health Security Agency. Meningococcal: The Green Book, chapter 22 (June 2025). https://assets.publishing.service.gov.uk/media/6849adb83a2aa5ba84d1df71/Meningococcal-green_book_chapter-22-10-6-25.pdf (accessed December 2025).
- UK Health Security Agency. Invasive meningococcal disease in England: annual laboratory confirmed reports for epidemiological year 2023 to 2024. https://www.gov.uk/government/publications/meningococcal-disease-laboratory-confirmed-cases-in-england-2024-to-2025/invasive-meningococcal-disease-in-england-annual-laboratory-confirmed-reports-for-epidemiological-year-2024-to-2025 (accessed December 2025).
- Best Practice BMJ. Meningococcal disease. https://bestpractice.bmj.com/topics/en-gb/542 (accessed November 2025).
- Burman C et al. Meningococcal disease in adolescents and young adults: a review of the rationale for prevention through vaccination. Hum Vaccin Immunother 2019;15:459-469.
- Guedes S et al. Epidemiology of invasive meningococcal disease and sequelae in the United Kingdom during the period 2008 to 2017 - a secondary database analysis. BMC Public Health 2022;22:521.
- National Institute for Health and Care Excellence. Clinical knowledge summary: Meningitis - bacterial meningitis and meningococcal disease. https://cks.nice.org.uk/topics/meningitis-bacterial-meningitis-meningococcal-disease/ (accessed December 2025).
- Langevin E, Lesage H, Juniper M. Invasive Meningococcal Disease Economic Burden: A Comprehensive Analysis. Poster presented at ISPOR Europe 2023; Copenhagen, Denmark. Poster EE744.
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January 2026 | NP-GB-MNU-WCNT-250003 (V1.0)