Research and analysis

Notified cases of invasive meningococcal disease

Updated 2 April 2026

Applies to England

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This publication is available at https://www.gov.uk/government/publications/invasive-meningococcal-disease-statistical-releases/notified-cases-of-invasive-meningococcal-disease

Overview

The UK Health Security Agency (UKHSA) has been investigating an invasive meningococcal disease (IMD) outbreak first detected in March 2026.

This release provides an up-to-date count of confirmed or probable notified cases connected to the incident. As this outbreak has transitioned from an enhanced incident to a standard incident, UKHSA will not publish additional updates unless there are further developments.

Case numbers refer to the position at 12:30pm the previous day, and include only those defined as either confirmed or probable.

During the outbreak, there were suspected cases notified to UKHSA, which needed to be actively investigated. These were not reported until the investigation had determined that they should be included as either confirmed or probable cases, or discarded as not related to the incident.

Case counts attached to the incident are provisional and subject to change (upwards or downwards) as intelligence about their connection to the incident improves, clinical assessment changes, or further microbiological characterisation becomes available. In outbreaks, case definitions are updated as new intelligence comes to light, which may affect the counts.

Notified cases of invasive meningococcal disease linked to Canterbury, Kent

As of 12:30pm on 1 April 2026, UKHSA has been notified of 21 confirmed cases of invasive meningococcal disease with epidemiological links to Canterbury, Kent.

All of the 21 confirmed cases are meningococcal group B (MenB). 18 of these have the outbreak strain subtype P1.12-1,16-183.

All cases have been hospitalised.

There have been 2 deaths since the start of the incident.

Daily case figures

The number of confirmed and probable cases can change when:

  • a case is laboratory confirmed
  • when the clinical assessment changes, including when new laboratory results are available
  • when further epidemiological information is available

The figures in Table 1 cannot be used to identify the number of new confirmed or probable cases from one day to the next. This also applies to total cases.

Table 1. Cases of invasive meningococcal disease linked to Canterbury, Kent by day from 16 March 2026

Date Total outbreak confirmed cases Outbreak confirmed MenB cases (subset of total outbreak confirmed cases) Outbreak confirmed MenB cases with outbreak strain (subset of outbreak confirmed MenB cases) Outbreak probable cases Total outbreak cases
01 April 2026 21 [note 2] 21 18 0 21
30 March 2026 21 [note 2] 21 17 0 21
26 March 2026 20 [note 2] 20 17 1 21
25 March 2026 20 [note 2] 20 17 2 22
24 March 2026 20 [note 2] 20 17 2 22
23 March 2026 20 [note 2] 20 17 3 23
22 March 2026 20 [note 2] 19 [note 1] 9 29
21 March 2026 20 [note 2] 19 [note 1] 9 29
20 March 2026 23 18 [note 1] 11 34
19 March 2026 18 13 [note 1] 11 29
18 March 2026 15 9 [note 1] 12 27
17 March 2026 9 6 [note 1] 11 20
16 March 2026 [note 1] 4 [note 1] [note 1] 1

Note 1: Information not reported

Note 2: A case initially classified as a confirmed case may be reclassified or discarded when further laboratory results and clinical information are available. This applies to situations where:

further testing (including results from specialist reference laboratories) rules out meningococcal disease

and 

there is an alternative diagnosis or where the clinical picture is no longer consistent with meningococcal infection

Note: The case numbers presented in Table 1 were confirmed at specific times of day for each of the releases: 16 March 2026 verified at 5:00pm, 17 March 2026 verified at 3:00pm, 18 March 2026 onwards verified at 12:30pm.

There have been 2 deaths since the start of the incident.

Definitions

Outbreak confirmed case 

For the purposes of the official counts related to the outbreak detected in Kent, an outbreak confirmed case is counted only where an individual meets the following criteria:

a clinical diagnosis of meningitis, sepsis, or other invasive disease (for example orbital cellulitis, septic arthritis)

and at least one of the following: 

  • Neisseria meningitidis isolated from a normally sterile site  
  • Gram-negative diplococci identified in a normally sterile site  
  • meningococcal DNA in a normally sterile site  
  • meningococcal antigen in blood, cerebrospinal fluid (CSF) or urine  

and

an onset of infection since 1 March 2026

and

an epidemiological link to the outbreak

and one of the following:

outbreak confirmed MenB case, including the subset of these confirmed to have the outbreak strain (outbreak confirmed MenB case with the outbreak strain)

or

outbreak confirmed case awaiting microbiological group  

Outbreak confirmed MenB case (subset of the outbreak confirmed cases)

A case that:

meets the definition of an outbreak confirmed case

and  

has a confirmed meningococcal group B result from the Meningococcal Reference Unit (MRU), UKHSA or accredited laboratory 

Outbreak confirmed MenB case with the outbreak strain (subset of outbreak confirmed MenB cases)

A case that:

meets the definition of an outbreak confirmed MenB case

and

has the outbreak strain subtype - P1.12-1,16-183

Outbreak confirmed case awaiting microbiological group (subset of the outbreak confirmed cases) 

A case that:

meets the definition of an outbreak confirmed case

and

awaiting microbiological group result or group not available

Outbreak probable case 

A clinical diagnosis of meningitis or septicaemia or other invasive disease where a doctor and/or microbiologist considers that meningococcal infection is the most likely diagnosis

and

an onset of infection since 1 March 2026 

and

an epidemiological link to the outbreak

Discarded case

A case where:

after further information has become available has been reassessed as no longer fulfilling any of the outbreak definitions

or

it has been laboratory confirmed as a non-group B meningococcal infection or a distinct non-outbreak strain of group B

Epidemiological link to the outbreak (any of the below)

An individual who either attended Club Chemistry or resided at the University of Kent, Canterbury campus between 1 and 26 March.

or

An individual who had close contact in the 7 days prior to symptom onset with either:

Data quality assurance

Data quality was assured through a manual checking process. Case counts attached to the incident are provisional and subject to change (upwards or downwards) as intelligence about their connection to the incident improves, clinical assessment changes or further microbiological characterisation becomes available.

Further information about genomic sequencing

4 further genome sequences have been generated from this outbreak on 25 March 2026, in addition to the strain released publicly on 20 March 2026 (UKHSA identifier 1926231). These have been generated from outbreak confirmed MenB cases with the outbreak strain. Initial analysis confirms that these new genomes are all closely related to the first genome and support the epidemiological findings to date.

The four new genomes are available on pubMLST.org :

  • UKHSA identifier 1930355, pubMLST identifier 190683
  • UKHSA identifier 1930356, pubMLST identifier 190684
  • UKHSA identifier 1930357, pubMLST identifier 190682
  • UKHSA identifier 1930358, pubMLST identifier 190685

Further genome releases will be made available on pubMLST.org and will follow routine UKHSA data sharing protocols.

Further information and advice

Latest news and information

For latest updates see our rolling news report.

For the latest information and advice for the public see the meningitis B outbreak: what you need to know.

For detailed epidemiological information about the outbreak see the Meningococcal disease outbreak technical briefings.

For background information (including symptoms) see Meningococcal disease: background information.

For more information, resources and historic data see Meningococcal disease: guidance, data and analysis.

Antibiotics and vaccination figures

For latest figures on the number of vaccinations and antibiotics given as part of the outbreak response, see the meningitis outbreak NHS information hub.

Surveillance

UKHSA conducts regular monitoring of meningitis cases throughout the year. See the meningococcal disease laboratory-confirmed cases in England 2024 to 2025 report for the most recent figures.

Methodology

Further information on the data sources and methodology used in invasive meningococcal disease surveillance can be found in data sources and methodology used in invasive meningococcal disease surveillance.

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