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Medical Professionals

Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find one of our health articles more useful.

This disease is notifiable in the UK - see NOIDs article for more detail.

Continue reading below

What is Meningitis?

Meningitis is an inflammation of the meninges, the outer membranes covering the brain and spinal cord. The inflammation may be caused by infection with viruses, bacteria, other micro-organisms, or non-infective causes.1

Viral meningitis is more common and usually more benign than bacterial meningitis but all cases of suspected meningitis should be managed as though having bacterial meningitis, until proven otherwise.

Meningococcal disease refers to meningitis and/or septicaemia caused by Neisseria meningitidis (the meningococcus). It presents as bacterial meningitis (15% of cases), septicaemia (25% of cases), or as a combination of the two presentations (60% of cases).2

See also the separate Sepsis (Septicaemia) article.

How common is meningitis? (Epidemiology)1

  • The annual incidence of acute bacterial meningitis in developed countries is estimated to be 1-2 per 100,000.

  • Meningococcal disease is very rare:

    • There were 525 cases of invasive meningococcal disease (IMD) in England in 2018/19 compared with 754 cases in 2017/18.

    • MenB accounted for 58% of all cases, MenW 22%, MenY 11%, and MenC 8%.

    • The incidence in infants decreased from 16 per 100,000 population in 2017/18 to 9 per 100,000 in 2018/19 (55 cases), and from 4 in 100,000 in children aged 1–4 years to 3 per 100,000 (74 cases).

    • Young adults aged 15–24 years accounted for 16% (82 cases) and people aged over 25 years accounted for 49% (257 cases) of all laboratory-confirmed cases of invasive meningococcal disease.

  • Tables are available for notified cases of acute meningitis in England and Wales - in 2017 there were 436 notifications, compared to 1,251 10 years previously in 20073.

  • The epidemiology of bacterial meningitis has changed in the UK over the past two decades with an evolving vaccination programme.

  • Meningitis occurs in people of all age groups but infants are at most risk of bacterial meningitis and meningococcal disease, with another peak in teenagers and young adults.

  • Viral meningitis is most common, accounting for over half of cases, but bacterial meningitis remains important, particularly as it has a high mortality.4 Many cases of viral meningitis are thought to go unreported - in 2005-6, for example, there were ten times as many people admitted to hospital with a diagnosis of viral meningitis as there were notifications of the condition.5

  • It has been estimated that an average GP will only see one or two cases of bacterial meningitis in the course of their career.

  • The incidence of culture-proven neonatal meningitis is estimated at 0.3 per 1,000 live births in developed countries.6

Meningitis risk factors2

  • Young age is the most significant risk factor. The incidence of bacterial meningitis and meningococcal disease is highest in children aged under 2 years and declines during childhood. There is also an increased risk in adolescence and early adulthood.

  • Winter.

  • Absent or non-functioning spleen.

  • Older age (more than 65 years).

  • Immunocompromised state (eg, HIV infection or chemotherapy).

  • Incomplete immunisation.

  • People with leukaemia or lymphoma.

  • Organ dysfunction, eg, liver or kidney disease.

  • Smoking.

  • Living in overcrowded households, college dormitories, or military barracks.

  • Contact with someone with Hib disease or meningococcal disease, or recently been to an area with an outbreak of meningococcal disease.

  • Family history of meningococcal disease.

  • Previous episode of bacterial meningitis or meningococcal disease.

  • Cranial anatomical defects — congenital or acquired.

  • Cochlear implants.

  • Cerebrospinal leak.

  • Contiguous infection, eg, otitis media, sinusitis, pneumonia, mastoiditis.

  • Sickle cell disease.

Risk factors for recurrent bacterial meningitis:

  • Primary or secondary immunodeficiency, including:

    • HIV.

    • Congenital complement deficiency or acquired inhibition.

    • Reduced or absent spleen function.

    • Hypogammaglobulinaemia.

  • Communication between the cerebrospinal fluid and external surface, eg, prior trauma or surgery, or a congenital anomaly.

Continue reading below


Viral causes are most common.

Bacterial meningitis27

Some of the more common causative organisms are listed below. This changes over time - the vaccination programme has been guided by this, and has had some impact on the subsequent epidemiology.

Age-specific common causes:

  • Neonates: group B streptococci, Listeria monocytogenes, Escherichia coli.

  • Infants and young children: Haemophilus influenzae type b, if younger than 4 years and unvaccinated; Neisseria meningitidis, Streptococcus pneumoniae.

  • Adults and older children: S. pneumoniae, H. influenzae type b, N. meningitidis, Gram-negative bacilli (such as non-type b H. influenzae, Klebsiella, Pseudomonas, Enterobacter), staphylococci, enterococcus species, streptococci and L. monocytogenes.

  • Elderly and immunocompromised: S. pneumoniae, L. monocytogenes, tuberculosis (TB), Gram-negative organisms.

Hospital-acquired and post-traumatic meningitis (may often be multidrug-resistant) tend to involve Klebsiella pneumoniae, E.coli, Pseudomonas aeruginosa, or Staphylococcus aureus.

N. meningitidis can cause local outbreaks among young adults; there is increased incidence in late winter or early spring. Meningococcal meningitis is endemic in parts of Africa, India and other developing nations. Periodic epidemics occur in sub-Saharan Africa as well as among religious pilgrims travelling to Saudi Arabia for the Hajj.

Syphilis and TB are rarer causes in those with relevant risk factors.

Neonatal meningitis6

See also the separate Congenital, perinatal and neonatal infections article.

  • Neonates are at greater risk of meningitis. Risk factors for the development of meningitis include low birth weight (below 2500 g), premature delivery, premature rupture of membranes, traumatic delivery, fetal hypoxia and maternal peripartum infection.

  • Intrapartum prophylactic antibiotics in pregnant mothers who carry, or who are at risk of colonising, group B streptococci, have been effective in reducing the risk of early neonatal group B streptococcal meningitis, although it remains one of the most common causative organisms.

  • E.coli is another common pathogen in this group, and particularly in very low-birth-weight babies.

  • Caesarean section reduces the risk of transmission of herpes simplex virus (HSV) when present and active in the mother.

  • In developed countries, overall incidence and mortality from bacterial meningitis among neonates has decreased but there has not been a significant decrease in long-term complications such as cerebral palsy, learning disability, seizures and hearing impairment.

  • Mortality following HSV infection of the central nervous system is 4-14%. HSV-1 and HSV-2 have the same risk of mortality but HSV-2 is more often associated with long-term complications such as cerebral palsy, general learning disability, seizures, microcephaly and visual impairment8.

Aseptic meningitis4910

CSF has cells but is Gram-stain negative and no bacteria can be cultured on standard media. Causes include:

  • Viral infection - eg, enteroviruses (echovirus, Coxsackievirus), mumps, HSV and herpes zoster virus, HIV, measles, influenza, arboviruses. Enteroviruses are the most common cause of meningitis in immunocompetent adults in the UK. Exact viral aetiology differs between countries.11

  • Fungal infection: fungal meningitis is rare but can be life-threatening. People with immunodeficiency (eg, AIDS, leukaemia, immunosuppressant medication) are at higher risk. Fungal causes of meningitis include infection with Cryptococcus, Histoplasma and Coccidioides species.

  • Parasites - eg, eosinophilic meningitis caused by angiostrongyliasis.

  • Other possible causative organisms include atypical tuberculosis (TB), syphilis, Lyme disease, leptospirosis, listeriosis and brucellosis.

  • Kawasaki disease.

  • Mollaret's meningitis.

  • Partly treated bacterial meningitis.

Non-infective meningitis

Meningeal inflammation can be caused by meningeal infiltration by:


See also the separate Ill and feverish child and Fever and night sweats articles.

Invasive meningococcal disease

Invasive meningococcal disease may present with septicaemia, meningitis or a combination of both. See the separate Meningococcal disease article.

  • A generalised non-blanching petechial rash, beyond the distribution of the superior vena cava, or a purpuric rash in any location, in an ill child, is strongly suggestive of meningococcal septicaemia and should lead to urgent treatment and referral to secondary care.

  • The following features in an ill child should prompt consideration of a diagnosis of invasive meningococcal disease: petechial rash, altered mental state, cold hands and feet, extremity pain, fever, headache, neck stiffness, skin mottling.

  • Meningococcal meningitis and/or septicaemia may also present with capillary refill time more than two seconds, unusual skin colour and hypotension.

  • Meningococcal septicaemia without meningitis does not tend to present with stiff neck, back rigidity, bulging fontanelle, photophobia, Kernig's sign, Brudzinski's sign, paresis, focal neurological deficits or seizures.

Transfer all suspected cases urgently to secondary care for a second opinion if there is any doubt. Arrange emergency medical transfer to hospital by telephoning 999.

Strongly suspect bacterial meningitis in people with all the symptoms in the red flag combinations:

  • Fever.

  • Headache.

  • Neck stiffness, including more subtle discomfort or reluctance to move the neck.

  • Altered level of consciousness or cognition (including confusion or delirium).

Strongly suspect meningococcal disease in people with any of these red flag combinations:

  • Haemorrhagic, non-blanching rash with lesions larger than 2 mm (purpura).

  • Rapidly progressive and/or spreading non-blanching petechial or purpuric rash.

  • Any symptoms and signs of bacterial meningitis.

Do not rule out meningococcal disease just because a person does not have a rash.

Bacterial meningitis and meningococcal disease are rapidly evolving conditions. They can present with non-specific symptoms and signs (without the red flag combination for bacterial meningitis or meningococcal disease), particularly in young babies and older adults.

The more symptoms and signs a person has, the more likely it is that they have bacterial meningitis. They may be difficult to distinguish from other infections with similar symptoms and signs.

Symptoms and signs may be more difficult to identify in young people and young adults, who may appear well at presentation. Meningitis and sepsis can occur at the same time, particularly in people with a rash.

Children and young people with bacterial meningitis commonly present with non-specific symptoms and signs, including fever, vomiting, irritability, reduced feeding in babies, and upper respiratory tract symptoms. These may be difficult to distinguish from other viral infections. Some children with bacterial meningitis present with seizures.

Children and young people with more specific symptoms and signs are more likely to have bacterial meningitis or meningococcal septicaemia, and the symptoms and signs may become more severe and more specific over time.

Classical signs of meningitis (neck stiffness, bulging fontanelle, high pitched cry) are often absent in infants with bacterial meningitis.

Consider other non-specific features of the presentation and use clinical judgement, taking into account:

  • The level of parental or carer concern (particularly compared with previous illness in the child or young person, or their family).

  • The speed of progression of the illness.

  • The overall severity of the illness.

Clinical presentation of meningitis may include:

  • Non specific features: fever, headache, vomiting, nausea, lethargy, irritability, muscle or joint pains, refusing food/drink, respiratory symptoms. Less common nonspecific symptoms include chills, shivering, diarrhoea, abdominal pain, sore throat, coryzal symptoms.

  • Stiff neck (generally not present in children under the age of 1 year or in patients with altered mental state).

  • Non-blanching rash.

  • Back rigidity.

  • Bulging fontanelle (in infants).

  • Photophobia.

  • Leg pain.

  • Capillary refill time >2 seconds, cold hands and feet.

  • Unusual skin colour.

  • Altered mental state, unconsciousness, anxiety toxic/moribund state.

  • Shock: other signs of shock include tachycardia and/or hypotension, respiratory distress, poor urine output in addition to increased capillary refill time, altered mental state, leg pain, cold hands and feet and unusual skin colour.

  • Kernig's sign (pain and resistance on passive knee extension with hips fully flexed).

  • Brudzinski's sign (hips flex on bending the head forward).

  • Paresis, focal neurological deficits (including cranial nerve involvement and abnormal pupils).

  • Seizures.

It often presents a diagnostic challenge in the early stages in primary care:

  • In the early stage of meningitis, features can be vague and nonspecific, similar to other infectious conditions with less catastrophic outcomes than meningococcal disease, making diagnosis a challenge in primary care, and safety-netting information particularly important. The disease can progress very rapidly.

  • Classic symptoms are not evident in infants and also not often seen in the elderly.

  • Fever is not necessarily present, especially in neonates.

  • Some children and young people will present with mostly nonspecific symptoms or signs and the conditions may be difficult to distinguish from other less important infections presenting in this way. Children and young people under the age of 16 with more specific symptoms and signs are more likely to have bacterial meningitis or meningococcal septicaemia and the symptoms and signs may become more severe and more specific over time.

  • A study of children aged 16 years or younger with meningococcal disease found that classical signs such as haemorrhagic rash, meningism and impaired consciousness did not tend to appear until after 13-22 hours. However, more nonspecific features such as leg pain, cold hands and feet and abnormal skin colour appeared much earlier with a median onset of 7-12 hours. These earlier features are thus very important in early diagnosis and therefore earlier initiation of potentially life-saving treatment.12

  • Most patients with viral meningitis present with subacute neurological symptoms developing over 1-7 days. Chronic symptoms lasting longer than one week suggest meningitis caused by some viruses as well as TB, syphilis or fungi. Viral meningitis may be clinically indistinguishable from bacterial meningitis but features may be more mild and complications (eg, focal neurological deficits) less frequent. Any person presenting with suspected meningitis should be managed as having bacterial meningitis until proved otherwise.

Early recognition of bacterial meningitis/meningococcal disease is vital to improve prognosis.

Continue reading below

Differential diagnosis2

Acute bacterial meningitis can present with common, non-specific clinical features. Differential diagnoses include:

  • Other causes of pyrexia and severe infection.

  • Other infective meningitis and meningoencephalitis, including:

    • Viral meningitis.

    • Fungal meningitis.

    • Tuberculous meningitis.

  • Drug-induced meningitis, eg, nonsteroidal anti-inflammatory drug, amoxicillin, ranitidine, trimethoprim/sulfamethoxazole).

  • Sepsis.

  • Pneumonia.

  • Intracranial abscess.

  • Other causes of altered mental state and coma - eg, encephalitis, subarachnoid haemorrhage, brain tumours.

  • Other causes of petechial/purpuric rashes:

    • Other infections, eg, enterovirus, Epstein-Barr virus, rubella, adenoviruses, and respiratory viruses.

    • Non-infective causes, eg, clotting factor or platelet deficiencies.

    • Petechiae in the eyes or on the face may also result from non-infective causes (such as sneezing, coughing, vomiting, and trauma).


Investigations must not delay treatment. Any person with suspected meningitis or meningococcal disease must be sent immediately to hospital by 999 emergency ambulance. The following investigations may be carried out in secondary care.

Bacterial throat swab
For people with suspected bacterial meningitis, perform a bacterial throat swab for meningococcal culture, preferably before starting antibiotics. Indicate on the request form that this is specifically for meningococcal culture.

Blood tests:

  • Blood culture.

  • White blood cell count (including neutrophils).

  • Blood C-reactive protein (CRP), or procalcitonin (PCT) if CRP is not available.

  • Blood glucose (to calculate cerebrospinal fluid to blood glucose ratio).

  • Whole-blood diagnostic polymerase chain reaction (PCR), including meningococcal and pneumococcal.

Take bloods, give antibiotics and stabilise the person before imaging. Do not routinely perform neuroimaging before lumbar puncture.

  • Perform imaging if the person has risk factors for an evolving space-occupying lesion or any of these symptoms or signs, which might indicate raised intracranial pressure:

    • New focal neurological features (including seizures or posturing).

    • Abnormal pupillary reactions.

    • Glasgow Coma Scale (GCS) score of 9 or less, or a progressive and sustained or rapid fall in level of consciousness.

Do not perform a lumbar puncture until these factors have been resolved.

Lumbar puncture:
See the separate Lumbar puncture and Cerebrospinal fluid articles for normal values and interpretation of abnormal CSF findings.

Perform the lumbar puncture before starting antibiotics, unless it is not safe to do so or it will cause a clinically significant delay to starting antibiotics. Cerebrospinal fluid investigations:

  • Red and white cell count and cell type (including differential white cell count).

  • Total protein.

  • Glucose concentration (to calculate cerebrospinal fluid to blood glucose ratio).

  • Microscopy for bacteria (using gram stain); microbiological culture and sensitivities

  • PCR for relevant pathogens.

Store the remaining cerebrospinal fluid in case more tests are needed.

Meningitis treatment and management

Management includes supportive treatment (including fluids, antipyretics, antiemetics), treatment of the causative organism and treatment of any complications - eg, seizures, raised intracranial pressure. See also the articles on specific infections for management of rarer causes of meningitis such as tuberculosis, fungi and parasites.

Management of viral meningitis45

  • The general principles of management for all viral meningitis include supportive therapy - eg, analgesia, antipyretics, nutritional support and hydration. There is no specific treatment for viral meningitis.

  • Enteroviral meningitis: usually self-limiting and no specific therapy is required unless there is hypogammaglobulinaemia (immunoglobulins required).

  • Aciclovir is considered beneficial in treating herpetic viral infections but only if given very early in the course of the infection and evidence for benefit is limited. Intravenous aciclovir should be started immediately if there is any suspicion of herpes simplex encephalitis. Evidence for benefit is for encephalitis, not for meningitis.

  • Ganciclovir is effective for cytomegalovirus (CMV) infections but it has significant renal toxicity and close monitoring is mandatory.

Management of bacterial meningitis27

Management in primary care

  • The priority is urgent transfer to hospital.

  • Transfer any patient with suspected bacterial meningitis or suspected meningococcal septicaemia to secondary care as an emergency by telephoning (if in the UK) 999.

  • National Institute for Health and Care Excellence (NICE) guidelines for those under the age of 16 years advises that intramuscular or intravenous benzylpenicillin should be given before urgent transfer to hospital only if there is suspected meningococcal septicaemia with a non-blanching rash.

  • Benzylpenicillin should not be given if there is a history of anaphylaxis associated with penicillins or if giving antibiotics will delay urgent transfer to hospital.

  • If urgent transfer to hospital is not possible (eg, remote locations or adverse weather conditions), antibiotics should be given to any person with suspected bacterial meningitis.

  • UK guidelines for management in adults advise that benzylpenicillin (or a third-generation cephalosporin) is given immediately to those with signs of severe sepsis (hypotension, altered mental state, poor capillary refill time) or where it will take more than an hour to get the person to hospital.

  • Dose of immediate benzylpenicillin (where there is suspected meningococcal disease with a non-blanching rash or urgent transfer is not possible):

    • Children younger than 1 year of age: 300 mg.

    • Children 1-9 years of age: 600 mg.

    • Adults and children 10 years of age or older: 1200 mg.

Arrange emergency medical transfer to hospital by telephoning 999. Do not delay transfer to hospital to give antibiotics to people with suspected or strongly suspected bacterial meningitis or meningococcal disease.

Give intravenous or intramuscular ceftriaxone or benzylpenicillin to people with strongly suspected:

  • Bacterial meningitis if there is likely to be a clinically significant delay in transfer to hospital.

  • Meningococcal disease as soon as possible, unless this will delay transfer to hospital.

Do not give antibiotics if the person has severe antibiotic allergy to either ceftriaxone or benzylpenicillin. Otherwise, administer a single dose of parenteral benzylpenicillin (intravenously or intramuscularly):

  • Children aged 1-11 months — 300 mg.

  • Children aged 1–9 years — 600 mg.

  • Adults and children aged 10 years or over — 1200 mg.

Alternatively administer a single dose of ceftriaxone (intravenously or intramuscularly):

  • Children aged 1 month–11 years (body-weight up to 50 kg) — 80 mg/kg (intramuscularly). Maximum dose 2000 mg.

  • Children 9–11 years (body-weight 50 kg and above) — 2000 mg.

  • Adults and children aged 12–17 years — 2000 mg.

Management in secondary care

  • Management includes supportive treatment with analgesia, antipyretics, nutritional support and hydration. Metabolic and circulatory disturbances should be anticipated, monitored and corrected where necessary (hypoglycaemia, acidosis, hypokalaemia, hypocalcaemia, hypomagnesaemia, dehydration, anaemia and coagulopathy).

  • The choice of antibiotics and the duration of therapy should be guided by the microbiological diagnosis but initial 'blind' antibiotic therapy must be started immediately (see below).

Initial 'blind' therapy

  • Ceftriaxone: use the highest doses recommended by the British National Formulary (BNF) or the British National Formulary for Children (BNFC), or refer to local antimicrobial guidance.

  • If ceftriaxone is contraindicated, consider cefotaxime (see the BNFC for contraindications to ceftriaxone for pre-term babies under 41 weeks corrected gestational age).

  • Give intravenous amoxicillin in addition to ceftriaxone or cefotaxime for people with risk factors for Listeria monocytogenes.

  • Do not routinely give intravenous aciclovir unless herpes simplex encephalitis is strongly suspected.

  • Continue initial antibiotic treatment until the results of blood and cerebrospinal fluid tests suggest an alternative treatment is needed or there is an alternative diagnosis. If test results are normal, but bacterial meningitis is still suspected, get advice from an infection specialist.

  • If the cerebrospinal fluid results suggest bacterial meningitis, but the blood culture and whole-blood diagnostic polymerase chain reaction are negative:

    • Continue antibiotics for 10 days.

    • After 10 days, stop antibiotics if the person has recovered, or get advice from an infection specialist if they have not.

  • Antibiotic choice may be modified once a causative organism has been identified.

Meningitis caused by meningococci (N. meningitidis)
Give ceftriaxone. If ceftriaxone is contraindicated, consider cefotaxime. After 5 days, stop antibiotics if the person has recovered, or get advice from an infection specialist if they have not.

Prevention of secondary cases for close contacts of those with meningococcal meningitis is usually with ciprofloxacin or rifampicin.

Meningitis caused by S. pneumoniae
Give ceftriaxone. If ceftriaxone is contraindicated, consider cefotaxime (see the BNFC for contraindications to ceftriaxone for pre-term babies under 41 weeks corrected gestational age). After 10 days, stop antibiotics if the person has recovered, or get advice from an infection specialist if they have not.

Meningitis caused by H. influenzae type b
Give ceftriaxone. If ceftriaxone is contraindicated, consider cefotaxime. Get advice from an infection specialist when starting treatment. After 7 days, stop antibiotics if the person has recovered, or continue for a total of 10 days if they have not. Get further advice from an infection specialist if the person has not recovered after 10 days.

Meningitis caused by group B streptococci
Give ceftriaxone. If ceftriaxone is contraindicated, consider cefotaxime. Get advice from an infection specialist when starting treatment. After 14 days, stop antibiotics if the person has recovered, or get further advice from an infection specialist if they have not.

Meningitis caused by Enterobacterales (coliforms)
Give ceftriaxone. If ceftriaxone is contraindicated, consider cefotaxime. Get advice from an infection specialist on using meropenem as an alternative to ceftriaxone and cefotaxime, while awaiting antibiotic sensitivities. Review treatment once antibiotic sensitivities are available. After 21 days, stop antibiotics if the person has recovered, or get further advice from an infection specialist if they have not.

Meningitis caused by listeriosis
Give intravenous amoxicillin or ampicillin for 21 days. Get advice from an infection specialist on adding intravenous co-trimoxazole for the first 7 days. After 21 days, stop antibiotics if the person has recovered, or get advice from an infection specialist if they have not.

Corticosteroids for bacterial meningitis and meningococcal disease
Bacterial meningitis:

  • For people over 3 months with strongly suspected or confirmed bacterial meningitis, give intravenous dexamethasone. For babies between 28 days and 3 months old with strongly suspected or confirmed bacterial meningitis, get infection specialist advice on using dexamethasone.

  • When the causative organism is found: continue dexamethasone if it is pneumococcus or Haemophilus influenzae type b. Stop dexamethasone for all other organisms. If no causative organism is found, get advice from an infection specialist on whether or not to continue dexamethasone.

Meningococcal disease:
Do not routinely give corticosteroids to people with meningococcal disease. Consider low-dose replacement corticosteroids for people with meningococcal septic shock that is not responding to high-dose vasoactive agents.

Fluid restriction
Do not routinely restrict fluid intake to below routine maintenance needs in people with bacterial meningitis. Give maintenance fluids orally or by enteral tube, if tolerated.

Osmotic agents

  • Do not use glycerol in the management of bacterial meningitis in babies, children, young people and adults. Do not routinely use other osmotic agents (such as mannitol or hypertonic sodium chloride) in the management of bacterial meningitis.

  • If there are signs of raised intracranial pressure and concerns about brain herniation: consider osmotic agents (but not glycerol) as a temporary measure to reduce intracranial pressure. For adults, get urgent advice from critical care. For babies, children and young people, get urgent advice from paediatric critical care services.

Intracranial pressure monitoring
Do not routinely use invasive intracranial pressure monitoring in the management of bacterial meningitis. Get specialist advice on intracranial pressure monitoring if there are features of raised intracranial pressure or hydrocephalus.


Complications of bacterial meningitis occur in up to 30% of children and up to one-third of adults. Complications are more common in pneumococcal meningitis than in meningococcal meningitis.

Complications following pneumococcal meningitis occur in about 30% of people compared with 7% with meningococcal meningitis. The frequency of complications is much higher in meningococcal septicaemia (up to 57%).

  • Immediate: septic shock, including disseminated intravascular coagulation, coma with loss of protective airway reflexes, cerebral oedema and raised intracranial pressure, septic arthritis, pericardial effusion and haemolytic anaemia (H. influenzae).

  • Cerebral infarction occurs in one in four people with bacterial meningitis — this leads to focal neurological deficits.

  • Subdural effusions are a common complication in young children. Risk factors include young age, rapid onset of illness, low peripheral white cell count and high CSF protein.

  • Syndrome of inappropriate antidiuretic hormone secretion (SIADH).

  • Seizures: occur more commonly during the acute stage of the disease.

  • Delayed: decreased hearing, or deafness; other cranial nerve dysfunction, multiple seizures, focal paralysis, hydrocephalus, cognitive impairment, learning difficulties, ataxia, visual impairment, Waterhouse-Friderichsen syndrome and peripheral gangrene.

  • 30-50% of survivors of acute bacterial meningitis have permanent neurological sequelae, and over recent years the reduction in overall mortality has not been matched by a reduction in rate of complications.

  • Other complications include anxiety, and emotional and behavioural difficulties.


With prompt and adequate antimicrobial treatment and supportive therapy, the outcome of acute bacterial meningitis is excellent. Most deaths occur in the first 24–48 hours.

Factors that affect the prognosis of bacterial meningitis include:

  • Age: fatality rates are high among people at the extremes of age (neonates and older people). The case-fatality rates for bacterial meningitis are 4–10% in children and 25% in adults.

  • The causative organism: in England in 2018/19, the case-fatality rate for invasive meningococcal disease was 5%, 3–7% for Haemophilus influenzae and Streptococcus agalactia, 20–25% for Streptococcus pneumoniae, and 30–40% for Listeria monocytogenes.

  • Presence of comorbidities.

  • Severity at presentation.

In children aged up to 18 years with bacterial meningitis, other significant prognostic factors include:

  • Symptoms lasting more than 48 hours before admission.

  • Coma/impaired consciousness.

  • Prolonged seizures (more than 12 hours after admission).

  • Prolonged fever (more than 7 days).

  • Shock.

  • Peripheral circulatory failure.

  • Respiratory distress.

  • Absence of petechiae.

  • Male gender.

  • S. pneumoniae being the causative organism.

Features associated with a poor prognosis in adults include:

  • Low Glasgow Coma Scale score on admission (low level of consciousness).

  • Tachycardia.

  • Absence of rash.

  • Thrombocytopenia.

  • Raised ESR.

  • Positive blood culture.

  • Cerebrospinal fluid leucocyte count of less than 1000 x 109 cells per mL.

The prognosis for viral meningitis is usually excellent, with complete resolution usually within 10 days. There may be longer-term sequelae, including headaches, and cognitive and psychological issues.4

Meningitis prevention

See the separate Immunisation schedule (UK), Hib vaccination, Meningococcal vaccination and Pneumococcal vaccination articles.

  • Vaccination programme. In the UK, this currently includes:13

    • Childhood vaccination against H. influenzae type b, meningococcus groups B and C and S. pneumoniae.

    • Quadrivalent vaccine (meningococcus groups A, C, W, Y) for teenagers.

    • Pneumococcal vaccination in those aged 65 years.

  • Intrapartum screening for Group B streptococcus and antibiotic prophylaxis.

  • Meningitis and meningococcal sepsis are notifiable diseases in the UK. Appropriate antibiotic prophylaxis of people in close contact with those diagnosed is arranged by the local public health team.

Further reading and references

  1. Meningitis - bacterial meningitis and meningococcal disease; NICE CKS, March 2024 (UK access only)
  2. Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management; NICE guidance (March 2024)
  3. Notifiable diseases: historic annual totals; GOV.UK
  4. Griffiths MJ, McGill F, Solomon T; Management of acute meningitis. Clin Med (Lond). 2018 Mar;18(2):164-169. doi: 10.7861/clinmedicine.18-2-164.
  5. Logan SA, MacMahon E; Viral meningitis. BMJ. 2008 Jan 5;336(7634):36-40. doi: 10.1136/bmj.39409.673657.AE.
  6. Ku LC, Boggess KA, Cohen-Wolkowiez M; Bacterial meningitis in infants. Clin Perinatol. 2015 Mar;42(1):29-45, vii-viii. doi: 10.1016/j.clp.2014.10.004. Epub 2014 Dec 6.
  7. McGill F, Heyderman RS, Michael BD, et al; The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults. J Infect. 2016 Apr;72(4):405-38. doi: 10.1016/j.jinf.2016.01.007. Epub 2016 Feb 2.
  8. Cherpes TL, Matthews DB, Maryak SA; Neonatal herpes simplex virus infection. Clin Obstet Gynecol. 2012 Dec;55(4):938-44. doi: 10.1097/GRF.0b013e31827146a7.
  9. Mount HR, Boyle SD; Aseptic and Bacterial Meningitis: Evaluation, Treatment, and Prevention. Am Fam Physician. 2017 Sep 1;96(5):314-322.
  10. McGill F, Griffiths MJ, Bonnett LJ, et al; Incidence, aetiology, and sequelae of viral meningitis in UK adults: a multicentre prospective observational cohort study. Lancet Infect Dis. 2018 Sep;18(9):992-1003. doi: 10.1016/S1473-3099(18)30245-7. Epub 2018 Jun 29.
  11. McGill F, Griffiths MJ, Solomon T; Viral meningitis: current issues in diagnosis and treatment. Curr Opin Infect Dis. 2017 Apr;30(2):248-256. doi: 10.1097/QCO.0000000000000355.
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  13. Routine childhood immunisation schedule

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