The majority of meningococcal disease occurs in infants less than five years of age, with a peak incidence in those under 1 year of age. There is a smaller, secondary peak in incidence in young adults aged between 15 - 19 years of age.

Most cases of meningococcal disease occur sporadically, with less than 5% of cases occurring in clusters. Outbreaks of meningococcal disease are more common among teenagers and young adults, and outbreaks have been reported in schools and universities. Public health interventions may include vaccination (depending on serogroup) and chemoprophylaxis.

Meningococcal disease shows marked seasonal variation with a peak in winter and a low level in summer. The winter season coincides with that of influenza. (see News and Events, Seasonal Diseases)

Meningococci are divided into distinct serogroups, according to their polysaccharide outer capsule. The most common serogroups that cause disease worldwide are groups B, C, A, Y and W135. Prior to the introduction of Men C vaccine, most disease in the UK was caused by serogroups B and C.

However, the number of cases caused by serogroup C have significantly reduced in all age groups since routine Men C vaccination was introduced (see Vaccination against Meningococcal disease) and serogroup B now accounts for 85-90% of all cases of meningococcal disease.

Meningococcal disease has an overall case fatality rate of approximately 10%, however this varies by a number of factors, including serogroup, age, and prompt antibiotic treatment. More deaths are caused by septicaemia than by meningitis.

Epidemiological data is obtained from 3 main sources:

1. Notifications: Based on clinical diagnosis (statutory)
2. Laboratory Confirmed Reports of invasive meningococcal disease: Routine laboratory reports using data from the Meningococcal Reference Unit (MRU)
3. Death data: From Office of National Statistics' death certificate information. Data from the routine laboratory reporting system (from the MRU) and ONS deaths are matched.

Meningococcal Reference Unit (MRU) isolates of Neisseria Meningitidis - England and Wales

Epidemiological year (from 1 July to 30 June the following year)

• Table 1: Invasive meningococcal, E&W by capsular group & epi year (PDF, 164 KB) 
• Table 2: Invasive meningococcal, E&W by capsular group, epi year & region (PDF, 251 KB)   
• Table 3: Invasive meningococcal, E&W by age group, epi year & region (PDF, 281 KB)          

Calendar year

• Table 4: Invasive meningococcal, E&W by capsular group & year (PDF, 163 KB)               
• Table 5: Invasive meningococcal, E&W by group, year & region (PDF, 257 KB)              
• Table 6: Invasive meningococcal, E&W by age group, year & region (PDF, 288 KB) 

 

Laboratory confirmed cases - England and Wales

Serogroup B disease

Epidemiological year (from 1 July to 30 June the following year)

• Table 7: Invasive meningococcal B, E&W by age group & epi year (PDF, 163 KB)

Serogroup C disease

Epidemiological year (from 1 July to 30 June the following year)

• Table 8: Invasive meningococcal C, E&W by age group & epi year (PDF, 163 KB)