Laboratory confirmed cases of invasive meningococcal infection in England: October to December 2023
Updated 28 November 2024
Applies to England
In England, the national UK Health Security Agency (UKHSA) Meningococcal Reference Unit (MRU) confirmed 92 cases of invasive meningococcal disease (IMD) between October and December 2023. Case numbers were less than the 186 cases in the equivalent period between October and December 2019, before pandemic restrictions were implemented in the UK. Cases in the years impacted by COVID-19 population control measures (1) were lower, with 19 and 65 confirmed in the equivalent periods in 2020 and 2021, respectively. Case numbers then increased to 102 in the equivalent period in 2022 (Table 1).
Earlier reports on IMD cases in England are available at: Meningococcal disease: guidance, data and analysis
With the complete withdrawal of COVID-19 containment measures in England from July 2021, overall case numbers are now returning to pre-pandemic levels driven mainly by group B meningococcal disease (MenB). Cases due to the other capsular groups remained very low because of the highly effective indirect (herd) protection provided by the adolescent meningococcal ACWY (MenACWY) conjugate vaccine programme introduced in August 2015, alongside direct protection in those vaccinated (2).
The distribution of meningococcal cases by capsular group causing IMD is summarised in Table 1, with MenB accounting for 89.1% of all cases (82 of 92), followed by MenY accounting for 6.5% (6 cases), and ‘Ungrouped/Ungroupable’ for 3.3% (3 cases) and MenC for 1.1% (1 case) in this quarter. There were no confirmed cases for other capsular groups, including MenW.
There were 82 MenB cases confirmed between October and December 2023, compared to 90 cases, 57 cases, 14 cases, and 109 cases in the corresponding period in 2022, 2021, 2020 and 2019 (pre-pandemic), respectively. Between October and December 2023, MenB was responsible for 93% of IMD cases in individuals under 25 years of age and 84% of cases in individuals aged 25 years or older (Table 2). For MenY, 5 out of the 6 cases were seen in individuals aged 25 years or older, while the 1 confirmed case of MenC was in an individual under 25 years. For ‘Ungrouped/Ungroupable’, 2 of the 3 cases were in individuals under 25 years.
The latest vaccine coverage information is available at Vaccine uptake guidance and the latest coverage data.
Table 1. Invasive meningococcal disease in England by capsular group and laboratory testing method: October to December only, 2022 and 2023
Capsular groups [note 1] |
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 | 19 | 16 | 21 | 18 | 50 | 48 | 90 | 82 |
C | – | – | – | – | 1 | 1 | 1 | 1 |
Ungrouped/Ungroupable [note2] | – | – | 1 | 2 | 3 | 1 | 4 | 3 |
W | – | – | 1 | – | – | – | 1 | – |
Y | – | 1 | 3 | 5 | 2 | – | 5 | 6 |
Z | 1 | – | – | – | – | – | 1 | – |
Total | 20 | 17 | 26 | 25 | 56 | 50 | 102 | 92 |
Note 1: No cases of group A, E, or X were confirmed during the periods summarised in the table.
Note 2: ‘Ungroupable’ refers to invasive clinical meningococcal isolates that were non-groupable, while ‘Ungrouped’ refers to those that were culture-negative but PCR screen (ctrA) positive and negative for the four genogroups (B, C, W and Y) routinely tested for.
Table 2. Invasive meningococcal disease in England by capsular group [note 3] and age group at diagnosis: October to December 2023
Age groups | Capsular group B | Capsular group C | Capsular group W | Capsular group Y | Capsular group ‘Other’ [note 4] | Total number | Total percentage |
---|---|---|---|---|---|---|---|
<1 year | 10 | – | – | – | – | 10 | 10.9% |
1 to 4 years | 7 | – | – | – | – | 7 | 7.6% |
5 to 9 years | 5 | 1 | – | – | – | 6 | 6.5% |
10 to 14 years | 1 | – | – | – | – | 1 | 1.1% |
15 to 19 years | 19 | – | – | 1 | – | 20 | 21.7% |
20 to 24 years | 8 | – | – | – | 2 | 10 | 10.9% |
25 to 44 years | 11 | – | – | – | – | 11 | 12% |
45 to 64 years | 8 | – | – | 2 | 1 | 11 | 12% |
65+ years | 13 | – | – | 3 | – | 16 | 17.4% |
Total | 82 | 1 | – | 6 | 3 | 92 | 100 |
Note 3: No cases of groups A, E, X or Z were confirmed during the period summarised in the table.
Note 4: ‘Other’ includes ungrouped or ungroupable isolates. ‘Ungroupable’ refers to invasive clinical meningococcal isolates that were non-groupable, while ‘ungrouped’ refers to those that were culture-negative but PCR screen (ctrA) positive and negative for the four genogroups (B, C, W and Y) routinely tested for.
References
1. Subbarao S, Campbell H, Ribeiro S, Clark SA, Lucidarme J, Ramsay M, and others (2021). ‘Invasive meningococcal disease, 2011-2020, and impact of the COVID-19 pandemic, England’. Emerging Infectious Diseases: volume 27 number 9, pages 2,495 to 2,497
2. Campbell H. Andrews N. Parikh SR, White J, Edelstein M, Bai X and others ( and others (2022), ‘Impact of an adolescent meningococcal ACWY immunisation programme to control a national outbreak of group W meningococcal disease in England: a national surveillance and modelling study’ Lancet Child and Adolescent Health: volume 6, issue 2