Meningitis Statistics UK

ALL MENINGOCOCCAL DISEASE – ENGLAND

We have used Hospital Episode Statistics (HES) admissions data (ICD10 code A39 meningococcal infection) to estimate the annual number of cases instead of Health Protection Agency (HPA) lab confirmed data because we are aware that some hospitals do not routinely send samples to the HPA and so these figures are likely to underestimate true incidence.

Although HES data contain duplicates, Dr Hannah Christensen and Dr Caroline Trotter at the University of Bristol have produced cleaned HES admissions data with duplicates removed over a seven year period in order to estimate burden of illness for their health economic model of meningococcal disease. These cleaned data represent on average 90% of raw HES admissions, so we have taken 90% of HES admissions to calculate meningococcal disease incidence in England.

2009/10

The figure used is the cleaned HES admissions from the year 2009/10.

Average annual cases representing the current burden of uncontrolled disease

To calculate the current burden of uncontrolled disease we took an average of cleaned HES data over the past ten years. However, cases of meningococcal C (MenC) disease are at present much lower than they were ten years ago due to the success of MenC vaccine (see fig 1), so we have adjusted our final figure to reflect present levels of MenC disease. We have therefore calculated the number of cases attributable to MenC disease by applying the proportion of MenC in the HPA lab confirmed data to each year of cleaned HES admissions (since HES data are not broken down by serogroup). We have then subtracted MenC cases in excess of the current levels from the total number of cases. This figure therefore represents the average cleaned yearly HES data from 2000/01 to 2009/10 corrected to remove cases of MenC disease which are in excess of current levels.

MENB – ENGLAND

2009/10

We have used cleaned HES data to calculate cases of meningococcal B (MenB) disease (for information about cleaned HES data see explanation behind all meningococcal disease - England). We used lab confirmed data from the Health Protection Agency (HPA) to calculate the proportion of all grouped meningococcal cases attributable to MenB in 2009/10, and applied this to the cleaned HES data from 2009/10.

This figure therefore represents cleaned HES data corrected to include only those cases attributable to MenB.

Average annual cases representing the current burden of uncontrolled disease

We applied the proportion of MenB cases in the HPA lab confirmed data for each year from 2000/01 to 2009/10 to the annual cleaned HES data to obtain the number of cases of meningococcal disease attributable to MenB only, and averaged this over the 10 years.

ALL MENINGOCOCCAL DISEASE - WALES

2009/10

Hospital Episode Statistics (which have been used to calculate cases in England) are available for England only.

Health Protection Agency (HPA) lab confirmed figures are available for Wales but are likely to under-represent true case numbers because some hospitals do not routinely send samples to the HPA. We have assumed that lab confirmed cases in Wales are under -ascertained by a similar proportion as in England. The ratio of the average cleaned HES admissions to the average lab confirmed meningococcal cases in England over the past ten years is 1.3. We have therefore applied an uplift of 1.3 to Welsh HPA lab confirmed data for 2009/10 to correct for this.

This figure therefore represents HPA lab confirmed data uplifted to adjust for under-reporting of cases.

Average annual cases representing the current burden of uncontrolled disease

To calculate the current burden of uncontrolled disease we uplifted the 10-year average of annual HPA lab-confirmed cases for Wales by 1.3 as above. However, we know that MenC cases are at present much lower than they were ten years ago due to vaccination (see fig 1), so our final figure was adjusted to reflect present levels of MenC disease. After calculating the 10-year average of HPA lab-confirmed MenC cases in Wales and uplifting by 1.3, we subtracted MenC cases in excess of current levels in Wales.

MENB - WALES

2009/10

We have taken HPA lab confirmed cases attributable to MenB in Wales in 2009/10 and applied an uplift of 1.3 to compensate for under-reporting (for information about uplifted lab confirmed data see explanation behind all meningococcal disease - Wales).

To obtain cases attributable to MenB, we assume that the proportion of MenB cases is the same for ungrouped cases as it is for grouped cases. Taking the total cases confirmed as MenB, we have added the proportion of ungrouped cases attributable to MenB (calculated as the percentage of lab-confirmed MenB cases out of all grouped cases), then applied the uplift to this sum.

Average annual cases representing the current burden of uncontrolled disease

This figure represents the average HPA lab confirmed cases attributable to MenB from 2000/01 to 2009/10. The uplift of 1.3 is applied to the 10-year average.

MENINGOCOCCAL DISEASE - SCOTLAND

2009/10

Health Protection Scotland (HPS) has the Meningococcal Invasive Disease Augmented Surveillance (MIDAS) system in place to try to capture all cases, so we have not introduced any correction for under-reporting.

As HPS data are produced per calendar year we have used data from 2009 to be as consistent as possible with data for the rest of the UK.

Average annual cases representing the current burden of uncontrolled disease

To calculate the current burden of uncontrolled disease we took the average number of cases over the past ten years. Due to the success of the MenC vaccine, cases of meningococcal C (MenC) disease are at present much lower than they were ten years ago, so our final figure was adjusted to reflect present levels of MenC disease.

The MIDAS system involves validating notifications of disease with laboratory reports. Some cases may be clinically diagnosed without ever receiving laboratory confirmation and these cases are listed as ungrouped. Some lab-confirmed cases are also classed as ungrouped because the laboratory is unable to identify the bacteria to serogroup level. Assuming that the proportion of MenC cases is the same for ungrouped cases as it is for grouped cases, we have calculated total cases attributable to MenC, by adding to the total cases confirmed as MenC, the proportion of ungrouped cases attributable to MenC (calculated as the percentage of lab-confirmed MenC cases out of all grouped cases). After calculating the 10-year average of MenC cases, we subtracted MenC cases in excess of current levels.

This figure therefore represents the average yearly HPS data from 2000 to 2009 corrected to remove cases of MenC disease which are in excess of 2009 levels.

MENB - SCOTLAND

2009/10

Health Protection Scotland’s MIDAS surveillance system involves validating notifications of disease with laboratory reports. Some cases may be clinically diagnosed without ever receiving laboratory confirmation and these cases are listed as ungrouped Some lab confirmed cases may also be found to be ungrouped because the laboratory is unable to identify the bacteria to serogroup level. We assume that the proportion of MenB cases is the same for ungrouped cases as it is for grouped cases. Taking the total cases confirmed as MenB in 2009, we have added the proportion of ungrouped cases attributable to MenB, calculated as the percentage of lab-confirmed MenB cases out of all grouped cases.

This figure therefore represents the HPS data from the year 2009 for MenB cases.

Average annual cases representing the current burden of uncontrolled disease

This figure represents the average of cases attributable to MenB (including a proportion of ungrouped cases as described above) over the past decade.

ALL MENINGOCOCCAL DISEASE – NORTHERN IRELAND

2009/10

Northern Ireland has an enhanced surveillance system in place to try to capture all cases, so we have not applied any uplift to these data.

This figure represents data for the year 2009/10, obtained from the Public Health Agency (PHA)

Average annual cases representing the current burden of uncontrolled disease

To calculate the current burden of uncontrolled disease we took the average number of cases over the past ten years. Due to the success of the MenC vaccine, cases of meningococcal C (MenC) disease are at present much lower than they were ten years ago, so our final figure was adjusted to reflect present levels of MenC disease.

Enhanced surveillance involves validating notifications of disease with laboratory reports. Most laboratory samples of bacteria are identified to serogroup level, however, some cases may be clinically diagnosed without ever being laboratory confirmed and these cases are listed as ungrouped. Some lab-confirmed cases are also listed as ungrouped because the laboratory is unable to identify the bacteria to serogroup level. Assuming that the proportion of MenC cases is the same for ungrouped cases as it is for grouped cases, we have calculated total cases attributable to MenC, by taking the total cases confirmed as MenC, and adding to this the proportion of ungrouped cases attributable to MenC (calculated as the percentage of lab-confirmed MenC cases out of all grouped cases). After calculating the 10-year average of MenC cases, we subtracted MenC cases in excess of current levels.

This figure therefore represents the average yearly PHA data from 2000/01 to 2009/10 corrected to remove cases of MenC disease which are in excess of 2009/10 levels.

MENB – NORTHERN IRELAND

2009/10

This figure has been derived from the Public Health Agency (PHA) enhanced surveillance data . Enhanced surveillance involves validating notifications of disease with laboratory reports. Some cases may be clinically diagnosed without ever receiving laboratory confirmation and these cases are listed as ungrouped Some lab confirmed cases may also be found to be ungrouped because the laboratory is unable to identify the bacteria to serogroup level. We assume that the proportion of MenB cases is the same for ungrouped cases as it is for grouped cases. Taking the total cases confirmed as MenB in 2009/10, we have added the proportion of ungrouped cases attributable to MenB, calculated as the percentage of lab-confirmed MenB cases out of all grouped cases.

This figure therefore represents the PHA data for the year 2009/2010 for menB cases.

Average annual cases representing the current burden of uncontrolled disease

This figure represents the average of cases from the PHA data attributable to MenB (including a proportion of ungrouped cases as described above) over the past decade.

PNEUMOCOCCAL MENINGITIS – ENGLAND AND WALES

2009/10

We have used Hospital Episodes Statistics (HES) admissions data (ICD10 code G001 pneumococcal meningitis) to estimate cases in England because there may be a degree of under-reporting of cases to the Health Protection Agency, and to maintain consistency with our estimations of meningococcal disease. HES data contain duplicates, but Dr Caroline Trotter at the University of Bristol has produced cleaned HES admissions data with duplicates removed which represent on average 75% of raw HES admissions.

HES data are available for England only, but there is a statutory requirement for the notification of certain infectious diseases including pneumococcal meningitis across the UK. The prime purpose of the notifications system is speed in detecting possible outbreaks and epidemics. Notification of Infectious Disease (NOIDs) are likely to underestimate cases due to under-reporting, and we have assumed that the rate of under-reporting is the same across England and Wales.

To calculate total cases of pneumococcal meningitis in England and Wales, we calculated the ratio of notified cases in Wales compared to notifications for England and Wales together and used this ratio to uplift the “cleaned” English HES data to represent England and Wales.

Average annual cases representing the current burden of uncontrolled disease

Cases of pneumococcal meningitis have declined since pneumococcal vaccine was introduced in 2006/7, so we have used data from 2007/8 onwards to avoid overestimating the current burden of disease. This figure therefore represents the average yearly cleaned HES admissions data post vaccine introduction uplifted to account for additional cases in Wales (see explanation above for an explanation of the uplift).

PNEUMOCOCCAL – SCOTLAND

2009/10

Health Protection Scotland (HPS) has the Scottish Pneumococcal Invasive Disease Enhanced Reporting (SPIDER) system in place to try to capture all cases. As HPS data are produced per calendar year we have used data from 2009.

Average annual cases representing the current burden of uncontrolled disease

here has been a drop in cases of pneumococcal meningitis since pneumococcal vaccine was introduced in 2006, so we have only used data from 2007 onwards to avoid overestimating the current burden of disease.

PNEUMOCOCCAL – NORTHERN IRELAND

2009/10

These figures have been sourced from the Public Health Agency (PHA). As PHA data are produced per calendar year we have used data from 2009. Figures represent laboratory confirmation of the organism from blood or cerobrospinal fluid plus a clinical diagnosis of meningitis and are likely to underestimate true incidence of disease.

Average annual cases representing the current burden of uncontrolled disease

There has been a drop in cases of pneumococcal meningitis since pneumococcal vaccine was introduced in 2006, so we have only used data from 2007 - 2009 to avoid overestimating the current burden of disease.

HAEMOPHILUS INFUENZAE MENINGITIS – ENGLAND AND WALES

2009/10

We have taken data for Haemophilus influenzae meningitis from the Notifications of Infectious Disease (NOIDs). Although NOIDs may under-represent the true number of cases, due to the success of the Hib vaccine, cases Haemophilus influenzae meningitis are relatively few and so the error associated with under-reporting is likely to be small. As NOIDs data are produced per calendar year we have used data from 2009.

Average annual cases representing the current burden of uncontrolled disease

The conjugate Haemophilus influenzae b (Hib) vaccine was introduced to the UK childhood immunisation schedule in 1992 and dramatically reduced cases of disease. However by the end of the 1990s there was a small but significant resurgence in disease incidence. A catch up campaign starting in 2003 and a routine booster for 1-year olds introduced in 2006 have successfully reversed this trend. Incidence of Hib disease since the introduction of the booster has remained at very low levels.

We have used NOIDs data from 2007 – 2009 (post introduction of the booster) to represent the ongoing burden disease.

HAEMOPHILUS INFUENZAE MENINGITIS – SCOTLAND

2009/10

We have taken data for Haemophilus influenzae meningitis from Enhanced surveillance data from Health Protection Scotland (HPS). As HPS data is produced per calendar year we have used data from 2009.

Average annual cases representing the current burden of uncontrolled disease

The conjugate Haemophilus influenzae b (Hib) vaccine was introduced to the UK childhood immunisation schedule in 1992 and dramatically reduced cases of disease. However by the end of the 1990s there was a small but significant resurgence in disease incidence. A catch up campaign starting in 2003 and a routine booster for 1-year olds introduced in 2006 have successfully reversed this trend. Incidence of Hib disease since the introduction of the booster has remained at very low levels.

We have used HPS enhanced surveillance of invasive Haemophilus influenza disease data from 2007 – 2009 (post introduction of the booster) to represent the burden of disease.

HAEMOPHILUS INFUENZAE MENINGITIS – NORTHERN IRELAND

2009/10

We have taken data for Haemophilus influenzae meningitis from the Public Health Agency (PHA). As PHA data is produced per calendar year we have used data from 2009. Figures represent laboratory confirmation of the organism from blood or cerobrospinal fluid plus a clinical diagnosis of meningitis and are likely to underestimate true incidence of disease.

Average annual cases representing the current burden of uncontrolled disease

The conjugate Haemophilus influenzae b (Hib) vaccine was introduced to the childhood immunisation schedule UK in 1992 which dramatically reduced cases of disease. However by 1998 there was a small but significant resurgence in disease incidence. A catch up campaign was introduced in 2003 to reverse this trend and in order to keep incidence low a booster dose to be given at one year of age was introduced to the routine schedule in 2006. Incidence of Hib disease since the introduction of the booster dose has remained at very low levels.

We have used PHA data from 2007 – 2009 (post introduction of the booster at 12 months) to represent the burden of uncontrolled disease.

TB MENINGITIS – ENGLAND AND WALES

2009/10

We have taken data on TB meningitis from the Notification of Infectious Disease (NOIDs). As NOIDs data are produced per calendar year we have used data from 2009.
Average annual cases representing the current burden of uncontrolled disease

NOIDs data from the years 2000 – 2009 were used to calculate the average annual number of cases. NOIDs data may underestimate the true number of cases, due to under-reporting.

TB MENINGITIS – SCOTLAND

2009/10

These figures have been collected from the Enhanced Surveillance of Mycobacterial infections (ESMI) and sourced from Health Protection Scotland (HPS). As HPS data are produced per calendar year we have used data from 2009.

Ongoing burden of disease

HPS ESMI figures from 2000-2009 have been used to obtain the average yearly number of cases of TB meningitis in Scotland over the past ten years.

TB MENINGITIS – NORTHERN IRELAND

2009/10

These figures have been sourced from the Public Health Agency (PHA), enhanced TB surveillance. As PHA data are produced per calendar year, we have used data from 2009.

Ongoing burden of disease

PHA enhanced TB surveillance figures from 2006-2009 have been used to obtain the average yearly number of cases of TB meningitis in Northern Ireland, because we could only source data from 2006 onwards.

OTHER CAUSES OF BACTERIAL MENINGITIS – ENGLAND AND WALES

2009/10

We have used Notification of Infectious Disease (NOIDs) data (other specified and un-specified) for annual cases of other types of bacterial meningitis. As NOIDs data are produced per calendar year we have used data from 2009.

Average annual cases representing the current burden of uncontrolled disease

NOIDs data from the years 2000 – 2009 were used to calculate the average annual number of cases of meningitis caused by other bacteria.

OTHER CAUSES OF BACTERIAL MENINGITIS – SCOTLAND

2009/10

Figures have been sourced from Health Protection Scotland (HPS)* and include all cases of meningitis where bacteria other than meningococcal, pneumococcal, Haemophilus influenzae or TB were found in cerebrospinal fluid (CSF) in 2009.

Average annual cases representing the current burden of uncontrolled disease

Figures have been sourced from Health Protection Scotland (HPS)* and include all cases of meningitis where bacteria other than meningococcal, pneumococcal, Haemophilus influenzae or TB were found in cerebrospinal fluid (CSF) from 2000 to 2009.

*Consolidated CSF (figures from HPS Respiratory and Immunisation quarterly reports 2000-2001). HPS meningitis cases and CSF specimens data 2002-2009, Eisin McDonald Oct 2011.

OTHER CAUSES OF BACTERIAL MENINGITIS – NORTHERN IRELAND

2009/10

These figures have been sourced from the Public Health Agency (PHA). Figures represent laboratory confirmation of organisms from blood or cerobro-spinal fluid plus a clinical diagnosis of meningitis and are likely to underestimate true incidence of disease. As PHA data is produced per calendar year we have used data from 2009.

Average annual cases representing the current burden of uncontrolled disease


Figures have been sourced from Public Health Agency (PHA). Data represents the average annual number of cases of meningitis due to bacteria other than meningococcal, pneumococcal, Hib or TB over the period 2006 - 2009.

NEONATAL GROUP B SEPTICAEMIA – UK

This figure has been calculated from data sourced in Heath et al. Group B Streptococcal disease in UK and Irish infants younger than 90 days. The Lancet 2004;363:292-294.

This paper breaks down cases of invasive GBS disease by country. Only UK data was used to calculate this figure. So that GBS meningitis (which would have been included in “other causes of bacterial meningitis”) is not double counted, we have used the proportions of cases of septicaemia as quoted in the paper to calculate cases of septicaemia only.

The same data has been used to represent total number of cases in 2009/10 as well as the incidence of uncontrolled disease in general due to lack of more recent published data for the UK.


Eleanor Taylor
Pneumococcal meningitis
Pneumococcal meningitis at 8

I still can't believe the journey we have all been through.

More stories