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Meningitis and meningococcal disease
General information General informationMeningitis: Meningitis is infection of the meninges, the membranes that cover the brain and spinal cord. It can be caused by a variety of different organisms, including bacteria, viruses and fungi. The less common form of the disease, bacterial meningitis, is always associated with severe illness and can be fatal. By contrast, viral meningitis, which can be caused by several different viruses, is more common but usually less severe. In the UK, the most common cause of bacterial meningitis is infection with the meningococcal bacteria (Neisseria menigitidis) although other bacteria, including those that cause pneumococcal disease and tuberculosis, can cause meningitis. Meningococcal disease: In addition to causing meningitis, infection with Neisseria meningitidis bacteria can also cause meningococcal septicaemia (blood poisoning). Meningococcal disease is the collective name given to disease caused by Neisseria meningitidis infection. Disease may present as either meningococcal meningitis or meningococcal septicaemia or as both together. Meningococcal bacteria 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. Most meningococcal disease in the UK is caused by serogroups B and C. However, the number of cases caused by serogroup C has significantly reduced in the UK since routine vaccination was introduced in 1999 in those age groups targeted for vaccination. Vaccinations against serogroups A, Y and W135 are also available and are offered to travellers to certain parts of the world where these are prevalent. There is, as yet, no vaccination against serotype B, the strain responsible for most cases of meningococcal disease in the UK. Urgent treatment with antibiotics and appropriate hospital management is essential for someone with meningococcal disease. Meningitis and meningococcal disease are notifiable diseases in the UK and any doctor suspecting that a patient is suffering from either is required by law to report it. More information about meningitis and meningococcal disease is available from the following: EpidemiologyMeningococcal disease: The majority of meningococcal infections occur 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 coarsely with that of influenza. Most disease in the UK is caused by serogroups B and C. Before the introduction of vaccination against meningococcal C in the UK in 1999, data from the Health Protection Agency (HPA) for the years 1996 - 2000, show that serogroup B accounted for 59% of all cases, group C (36%) and other groups including W135 & A (5%). However, the number of cases caused by serogroup C have significantly reduced since routine vaccination was introduced. Meningococcal disease has a case fatality rate of approximately 10%. Meningitis caused by other organisms: The epidemiology of meningitis due to other organisms is more complex to ascertain. Cases of meningitis resulting from infection with measles virus, mumps virus or Haemophililus influeanzae B bacteria have decreased since the introduction of routine childhood vaccination against these diseases. After meningococcal disease, invasive infection with the bacterium Streptococcus pneumoniae (also called the pneumococcus) is one of the most frequently reported causes of bacteraemia (i.e. blood poisoning) and meningitis-see the HPA website for the number of laboratory-confirmed pneumococcal meningitis cases in England and Wales 1996-2005. The introduction of vaccination against several pneumococcus serotypes which are particularly associated with causing invasive disease is recommended for those aged over 65, individuals in a high risk group for infection and for all children (as part of the routine childhood immunisation programme since 2006). Data on incidence of invasive pneumococcal disease, including meningitis, since the introduction of routine pneumococcus vaccination for children in the UK, is still limited but initial results indicate that the incidence of invasive pneumococcal disease in children aged 2 years and under and due to serotypes included in the vaccine have shown a significant decrease (data from HPA website). Sources of surveillance data for WalesNotification data: It is a statutory requirement in England, Wales, and Northern Ireland to notify all cases of clinically diagnosed meningitis, whether or not microbiologically confirmed. This statutory requirement for the notification of certain infectious diseases came into being in 1891 and includes all forms of meningitis (whatever the cause). All clinically diagnosed cases of meningococcal septicaemia must also be notified. The NOIDS reports are available to download from the HPA website. Whenever possible, meningitis notifications are sub categorised i.e. meningococcal, pneumococcal, Haemophilus influenzae, viral, other specified and unspecified. The prime purpose of the NOIDs system is speed in detecting possible outbreaks and epidemics. Accuracy of diagnosis is secondary and since 1968 clinical suspicion of a notifiable infection is all that is required. If a diagnosis of meningitis later proves incorrect it should be denotified. With the NOIDs system, it is difficult to accurately identify duplicate forms received from more than one physician involved in the management of the same incident case, and to completely exclude through de-notification cases wrongly diagnosed as meningitis or sub-categorised incorrectly. Therefore trends in meningitis notifications should be interpreted with caution. Laboratory-confirmed meninogococcal disease: Over 50% of cases of meningococcal disease are 'laboratory-confirmed' cases. These are cases where a sample, usually of blood or spinal fluid, is taken from the sick patient and testing in a laboratory indicates the presence of meningococcal bacteria, or DNA from those bacteria. Additionally, further testing may establish which serogroup of meningococcal bacteria is responsible for disease. However, every year there are a number of cases of meningococcal disease which are not confirmed in the laboratory. These are cases where the patient clearly has symptoms of the disease and is diagnosed on the basis of these symptoms but there is no confirmation from laboratory tests either because it is not possible to take a sample or treatment has started before a sample can be taken (which of course kills the infecting organisms). The unconfirmed cases will not be counted in the data on laboratory-confirmed cases of disease. However, they represent a significant burden of disease. Enhanced Surveillance of Meningococcal Disease (ESMD): Regional enhanced surveillance of meningococcal disease has been carried out since 1998 with the aim of continually providing detailed and comparable information on the epidemiology of meningococcal disease across the whole of the UK. The minimum dataset includes notification details, demographic, clinical and microbiological information on all cases of meningococcal disease (whether laboratory-confirmed or not) in Wales reported by clinicians to local health protection teams, then via NPHS CDSC to the HPA in Colindale, London. These are the data that are used to produce the trends graph and accompanying data tables on this website unless stated otherwise. More information about ESMD is available from the HPA website Rates of meningitis and meningococcal disease in Wales1. Notifications of meningitis and meningococcal septicaemia in Wales: 1999-2007 Graph and data table of number of notifications of meningococcal septicaemia, total meningitis and specified type of meningitis in Wales: 1999-2007 (opens in new window) 2. Laboratory reports of Neisseria meningitidis in Wales: 1975-2007Graph and data table of number of laboratory reports* of Neisseria meningitidis, Type B and C, in Wales: 1975-2007 data (CSF and blood specimens only) (opens in new window) 3. Enhanced Surveillance of Meninogococcal Disease in Wales: 2000-2007All data recorded by epidemiological year (July-June) Graph and data table for meningococcal disease cases by epidemiological year in Wales (opens in new window) Graph and data table for meningococcal disease cases by serogroup and by epidemiological year in Wales (opens in new window) Graph of meningococcal disease cases by age group and epidemiological year in Wales and data table for meningococcal disease cases by age: epidemiological year 2006-2007 (opens in new window) Immunisation against meningitis CThe UK was the first country in the world to introduce meningococcal serogroup C conjugate (MenC) vaccination. Immunisation with (MenC) vaccine started in November 1999 for everybody up to the age of 18 years, and to all first year university students. This has since been extended to include everybody under 25 years of age. The MenC vaccination is included in the routine childhood immunisation schedule with doses given at three and four months of age, followed by a booster dose at around 12 months of age. The vaccination is also offered to anyone under the age of 25 who has not previously received it. The number of cases of meningococcal disease caused by serogroup C have significantly reduced since routine vaccination was introduced in those age groups targeted for vaccination. As there is no vaccine generally available to protect against serogroup B meningococcal disease (currently responsible for the majority of meningococcal infections), it is of the upmost importance that health professionals and the general public remain alert to the signs and symptoms of meningococcal disease. Work is currently being undertaken to develop a suitable group B meningococcal vaccine. More about the development of a group B meningococcus vaccine from the Meningitis Research Trust. The uptake of MenC (and other childhood) vaccination in Wales is recorded in the COVER (Coverage of Vaccination Evaluation Rapidly) report. This is published on both a quarterly and annual basis. Quarterly trend reports for each LHB and GP practice-based reports are also published. Use the link below to access all COVER reports from 2003-2007. Quarterly and annual coverage of childhood immunisation in Wales (Cover Reports) 2003-2007 (Select Polysaccharide vaccines for serogroups A and C have been available for some time and are used for travellers to parts of Africa and the Middle East. These vaccines are not effective in children under 2 years old and offer short term protection (3 to 5 years). A quadrivalent vaccine protecting against disease caused by serogroups A, C, W135 and Y is available for pilgrims travelling to the religious festivals of Hajj and Umra in Saudi Arabia. Travellers to these festivals must ensure their vaccination covers these four meningitis variants (more information from Department of Health website). Information about immunisation and vaccination is available from the NHS immunisation website at: http://www.immunisation.nhs.uk/ Requests for further surveillance dataIf further surveillance data for meningitis and meningococcal disease in Wales are required, it may be possible to provide them on special request using the surveillance data request form. Links to other meningitis/meningococcal surveillanceHealth Protection Agency (England and Wales)
Last updated: 16/06/2008 |
Immunisation (scheduled childhood) for annual and quarterly all Wales reports; Select
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