Meningitis: Bacterial Meningitis and Meningococcal Disease: Recognition and Management

Bacterial meningitis

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

• fever
• headache
• neck stiffness
• altered level of consciousness or cognition (including confusion or delirium).

Bacterial meningitis can still be strongly suspected based on clinical assessment, even in people who do not have all the symptoms in the red flag combination.

For more details see NICE  Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management guideline table 1 for babies, children and young people or table 2 for adults. 

Meningococcal disease

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

• haemorrhagic, non-blanching rash with lesions larger than 2 mm (purpura) (however do not rule out meningococcal disease in absence of a rash)
• rapidly progressive and/or spreading non-blanching petechial or purpuric rash
• any symptoms and signs of bacterial meningitis when combined with a non-blanching petechial or purpuric rash.

For more details see NICE  Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management guideline table 3.

When looking for a rash:

• check all over the body (including nappy areas), and check for petechiae in the conjunctivae
• note that rashes can be hard to detect on brown, black or tanned skin (look for petechiae in the conjunctiva)
• tell the person and their family members or carers to look out for any changes in the rash, because it can change from blanching to non-blanching

Bacterial meningitis

Be on heightened alert to the possibility of bacterial meningitis (including meningococcal meningitis) in people with any of these risk factors:

• missed relevant immunisations, such as meningococcal, Haemophilus influenzae type b (Hib) or pneumococcal vaccines
• reduced or absent spleen function
• congenital complement deficiency or acquired inhibition
• they are a student in further or higher education, particularly if they are in large shared accommodation (such as halls of residence)
• a family history of meningococcal disease
• they have been in contact with someone with Hib disease or meningococcal disease, or have been in an area with an outbreak of meningococcal disease
• a previous episode of bacterial meningitis or meningococcal disease
• a cerebrospinal fluid leak
• a cochlear implant
• risk factors for and clinical indicators of possible early-onset neonatal infection
• risk factors for and clinical indicators of possible late-onset neonatal infection

Meningococcal disease

Be on heightened alert to the possibility of meningococcal disease in people with any of these risk factors: 

• missed meningococcal vaccinations
• reduced or absent spleen function
• complement deficiency or inhibition
• they are a student in further or higher education, particularly if they are in large shared accommodation (such as halls of residence)
• a family history of meningococcal disease
• they have been in contact with someone with meningococcal disease, or have been in an area with an outbreak
• a previous episode of meningococcal disease.
• risk factors for and clinical indicators of possible early-onset neonatal infection
• risk factors for and clinical indicators of possible late-onset neonatal infection

For people who have had a previous episode of meningococcal disease, check for risk factors for recurrent bacterial meningitis and meningococcal disease. 

Risk factors for recurrent bacterial meningitis are:

• 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, for example caused by:
  • prior trauma or surgery
  • a congenital anomaly

The risk factor for recurrent meningococcal disease is primary or secondary immunodeficiency, including:

• HIV
• congenital complement deficiency or acquired inhibition
• reduced or absent spleen function

For all people with bacterial meningitis or meningococcal disease, take a history of:

• head trauma, surgery or cerebrospinal fluid leak
• immunisations
• medicines, including drugs that suppress the immune system (such as complement inhibitors).

Antibiotics should start within 1 hour of the person with suspected bacterial meningitis or meningococcal arriving at hospital (see Meningitis guideline).

Blood tests and lumbar puncture are performed before starting antibiotics (if it is safe to do so and will not cause a clinically significant delay to starting antibiotics)

Confirm a diagnosis of bacterial meningitis based on:

• clinical features and
• blood test results and
• lumbar puncture results

Bacterial throat swab

For people with suspected bacterial meningitis or meningococcal disease 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

Perform the following blood tests for people with suspected bacterial meningitis or meningococcal disease:

• blood culture
• white blood cell count (including neutrophils)
• blood C-reactive protein (CRP)
• blood glucose
• whole-blood diagnostic polymerase chain reaction (PCR), including meningococcal and pneumococcal
• HIV test
• Lactate

Do not rule out bacterial meningitis or meningococcal disease based only on a normal CRP, PCT, or white blood cell count.

Neuroimaging

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
  • a 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.

Take bloods, give antibiotics and stabilise the person before imaging.

Lumbar puncture

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.

If the person has started on antibiotics before having a lumbar puncture, perform a lumbar puncture as soon as possible (if it is safe to perform).

Treat and stabilise any of the following before performing a lumbar puncture:

• unprotected airway
• respiratory compromise
• shock
• uncontrolled seizures
• bleeding risk.

DO NOT perform lumbar puncture if there is:

• extensive or rapidly spreading purpura
• infection at the lumbar puncture site
• risk factors for an evolving space-occupying lesion
• any of these symptoms or signs, which might indicate raised intracranial pressure:
  • new focal neurological features (including seizures or posturing)
  • abnormal pupillary reactions
  • a Glasgow Coma Scale (GCS) score of 9 or less, or a progressive and sustained or rapid fall in level of consciousness.

Measure blood glucose in people immediately before lumbar puncture, so that the cerebrospinal fluid to blood glucose ratio can be calculated.

Cerebrospinal fluid investigations

Perform the following cerebrospinal fluid investigations in people with suspected bacterial meningitis:

• 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.

Discuss the following with patients with suspected bacterial meningitis and meningococcal disease and their family members and carers:

• the reasons for their suspected diagnosis, and any uncertainty about this
• when they can expect to know more
• the need for investigations (including lumbar puncture for bacterial meningitis)
• the timing of investigations and antibiotics.

For people who are unlikely to have bacterial meningitis or meningococcal disease, but who are sent home from hospital with an unconfirmed diagnosis:

• explain which symptoms and signs to look out for, and what changes should prompt them to return to hospital for further assessment e.g. if they develop new symptoms, if a rash changes from blanching to non-blanching, or if existing symptoms get worse
• direct them to sources of online information. 

This guideline is a summary of the NICE 240 NICE  Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management guideline. March 2024.