Research and analysis

Laboratory confirmed cases of invasive meningococcal infection in England: January to March 2023

Updated 29 August 2024

Applies to England

In England, the national UK Health Security Agency (UKHSA) Meningococcal Reference Unit (MRU) confirmed 165 cases of invasive meningococcal disease (IMD) between January and March 2023. Case numbers are similar to the equivalent period between January and March 2020, just before pandemic restrictions were implemented in the UK. Cases in the intervening years were lower, being 18 in the equivalent period in 2021, and 57 in the equivalent period in 2022 (see table 1).

The report on IMD cases in England in 2019 to 2020 is available here: Meningococcal disease: laboratory confirmed cases in England in 2019 to 2020 - GOV.UK (www.gov.uk)

With the complete withdrawal of containment measures in England from July 2021, overall case numbers are now similar to pre-pandemic levels and driven mainly by group B meningococcal disease (MenB). Cases due to the other meningococcal groups remain very low because of the highly effective indirect (herd) protection provided by the adolescent meningococcal ACWY (MenACWY) conjugate vaccine programme, alongside direct protection in those vaccinated.

The distribution of meningococcal cases by capsular group causing IMD is summarised in Table 1: MenB accounted for 94.5% (156 of 165) of all cases, followed by capsular group W (MenW; n=3, 1.8%), and group Y (MenY; n=3, 1.8%). There were no capsular group C (MenC) cases in this quarter in 2023 and no confirmed cases for other capsular groups.

There were 156 MenB cases confirmed between January and March 2023, compared to 51 cases, 12 cases and 110 cases in the corresponding period in 2022, 2021 and 2020 (pre-pandemic), respectively. Between January and March 2023, MenB was responsible for 94.9% of IMD cases in individuals under 25 years of age and 94.0% of cases in individuals aged 25 years or older (table 2). One of the 3 confirmed cases of MenW occurred in an individual aged under 25 years, while 2 of the 3 MenY cases were reported in individuals aged under 25 years.

The latest vaccination coverage information is available at: Meningococcal ACWY immunisation programme: vaccine coverage estimates

Table 1. Invasive meningococcal disease in England by capsular group and laboratory testing method: January to March 2023

Capsular groups* Culture and PCR (2022) Culture and PCR (2023) Culture only (2022) Culture only (2023) PCR only (2022) PCR only (2023) Total (2022) Total (2023)
B 12 28 15 27 24 101 51 156
Other/ungroupable/ungrouped** 1 3 1 3
W 1 1 3 2 1 5 3
Y 1 2 3
Total 13 30 19 29 25 106 57 165

*No cases of group A, E, X or Z were confirmed during the periods summarised in the table.

** ‘Ungroupable’ refers to invasive clinical meningococcal isolates that were non-groupable, while ‘ungrouped’ cases are those that were culture-negative but PCR screen (ctrA) positive and negative for the 4 genogroups [B, C, W and Y] routinely tested for.

Table 2. Invasive meningococcal disease in England by capsular group* and age group at diagnosis: January to March 2023

Age groups Capsular group B Capsular group C Capsular group W Capsular group Y Capsular group Other** Total Total percentage
<1 year 16 1 17 10.3%
1 to 4 years 15 15 9.1%
5 to 9 years 12 1 1 14 8.5%
10 to 14 years 8 1 9 5.5%
15 to 19 years 23 1 24 14.5%
20 to 24 years 19 19 11.5%
25 to 44 years 22 22 13.3%
45 to 64 years 22 1 1 1 25 15.2%
65+ years 19 1 20 12.1%
Total 156 3 3 3 165 100%

*No cases of other capsular groups were confirmed during the period summarised in the table.

**‘Other’ includes other ungrouped or ungroupable capsular groups. (‘Ungroupable’ refers to invasive clinical meningococcal isolates that were non-groupable, while ‘ungrouped’ cases are those that were culture-negative but PCR screen (ctrA) positive and negative for the four genogroups [B, C, W and Y] routinely tested for.)