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Meningitis

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Meningitis\: in
otherwise due to high mortality.
Aetiology\: bacterial, viral, fungal, non-infective (e.g. cancer, autoimmune, drugs).
Bacterial causes\: N . m e n i n g i t i d i s , S . p n e u m o n i a e , H . i n
Viral causes\: enteroviruses, HSV, VZV, mumps; accounts for over 50% of cases.
Risk factors\: young age, immunocompromise, asplenia, neonatal complications, overcrowding (e.g. university students).
Clinical features\: fever, headache, neck sti
meningococcal disease.
Investigations\: LP (within 1 hour), CSF analysis (cell count, gram stain, culture), blood cultures, CRP, CT head if focal
neurology.
Management\: IV antibiotics (ceftriaxone/cefotaxime), steroids (dexamethasone if >3 months), prophylactic antibiotics for
contacts, report to Public Health.
Complications\: hearing loss (33%), seizures, cognitive impairment, motor de
sequelae).
Prognosis\: bacterial meningitis has higher mortality; viral usually self-limiting with good prognosis.
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Introduction

1
Meningitis is caused by in
meningitis is more common than bacterial meningitis, but all cases should be treated as bacterial until proven otherwise, as
bacterial meningitis has a high mortality.
2
Figure 1. The meninges cover the brain and sit between the brain tissue and the skull
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Aetiology

Meningitis can be caused by bacteria, viruses, and fungi or be non-infective (secondary to some cancers, including
leukaemia and lymphoma, autoimmune diseases or drugs).
1-2

Bacterial meningitis

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The annual incidence of acute bacterial meningitis in developed countries is estimated at 2–5 per 100,000 population. It is
most common in infants, with a second peak in teenagers and young adults.
2
Transmission
1
Bacterial meningitis is transmitted via droplet spread and usually requires frequent or prolonged close contact. Bacteria in
the upper respiratory tract can then travel via the bloodstream to the meninges to cause invasive disease in susceptible
people.
4
Occasionally, meningitis can occur due to direct spread from a local source of infection (e.g. otitis media, mastoiditis).
Causative organisms
In neonates (\<1 month old), the common causative organisms are\:
1
S t r e p t o c o c c u s a g a l a c t i a e (Group B streptococci)
E s c h e r i c h i a c o l i
S t r e p t o c o c c u s p n e u m o n i a e
L i s t e r i a m o n o c y t o g e n e s
In babies over 3 months old, children and adults, the most common organisms are\:
1
N e i s s e r i a m e n i n g i t i d i s
S t r e p t o c o c c u s p n e u m o n i a e
H a e m o p h i l u s i n
Atypical causes of bacterial meningitis are rare, but include\:
Tuberculosis
Syphilis
Lyme disease
Meningococcal and pneumococcal disease
Meningococcal disease refers to meningococcal meningitis (caused by N . m e n i n g i t i d e s ), meningococcal sepsis
(where N . m e n i n g i t i d e s enters the bloodstream and causes the classical non-blanching rash) or a combination of
There were 525 cases of invasive meningococcal disease in England in 2018-19, a 30% decrease from the 755
both. 4
in 2017-18.
5
Pneumococcal disease is caused by invasive S t r e p t o c o c c u s p n e u m o n i a e , which includes pneumonia,
meningitis, and sepsis.
1
Vaccines are available for both infections\: meningococcal subgroups A, B, C, W and Y, Hib and 13 serotypes of
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pneumococcus.

Aseptic meningitis

Aseptic meningitis is diagnosed when cerebrospinal
2
bacterial culture on standard media. This can include viral and fungal causes.
Viral
Viral meningitis accounts for over half of all cases of meningitis. The most common pathogens are\:
2
Enteroviruses (e.g. echovirus, coxsackievirus)
Herpes simplex virus
Varicella-zoster virus
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Human immunode
In
Mumps
Fungal
Fungal meningitis is most commonly caused by C r y p t o c o c c u s. This is rare but can be life-threatening and is more
common in immunode
2

Risk factors

Risk factors for meningitis include\:
1-2
Young age
Neonatal complications (e.g. low birth weight, prematurity, premature rupture of membranes, maternal peripartum
infection, fetal hypoxia)
Asplenia
Immunocompromise (e.g. HIV, immunosuppressive medications)
Organ dysfunction
Smoking
Overcrowded living environment (e.g. university students, prisoners)

Clinical features

Meningitis classically presents with a triad of fever, neck sti
44% of adults with bacterial meningitis and is even less speci
7

Early features

Clinical features are typically vague and non-speci
1
Fever
Headache
Nausea and vomiting
Lethargy
Myalgia
Anorexia
Coryzal symptoms
Diarrhoea

Later features

As the infection progresses, clinical features become more speci
1-2
Bulging fontanelle in infants
Neck sti
Photophobia
Non-blanching rash\: petechiae or purpura
Kernig’s sign\: pain and resistance on passive knee extension with hips fully
Brudzinski’s sign\: knees and hips
Mottled skin, cold hands and feet
Leg pain
Altered mental state
Shock\: tachycardia, hypotension, respiratory distress, poor urine output
Neurological symptoms\: seizures, paresis, focal neurological de
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Recognition in the child
Parental concerns should be taken seriously. Consider the speed of progression and the overall severity of the
illness.
1
Early recognition is vital to improve the prognosis of acute bacterial meningitis, which can progress rapidly, with
symptoms often becoming more speci
1
The NICE tra (children under 5 years old) is useful for assessing all unwell young children.
8

Di

Di
2
In or other viral illnesses
Sepsis from any source
Encephalitis (in
Intracranial or spinal abscess
Subarachnoid haemorrhage
Brain or CNS malignancy

Investigations

Investigations are important, but they must not delay treatment in suspected meningitis.
2

Bedside investigations

Relevant bedside investigations include\:
1
Basic observations\: to assess for evidence of septic shock (e.g. hypotension, tachycardia, fever)
Blood glucose\: if altered mental state and for comparison with cerebrospinal

Laboratory investigations

Relevant laboratory investigations include\:
2
Full blood count\: may show raised white cell count or thrombocytopaenia
Urea and electrolytes\: may show evidence of dehydration or organ dysfunction
C-reactive protein\: elevated in infection
Coagulation screen\: may be deranged, especially if petechial rash or sepsis
Blood cultures\: for culture and sensitivity of causative organism
Meningococcal polymerase chain reaction (PCR)
Blood gas\: for lactate and acid-base status

Imaging

CT head is sometimes performed if there are focal neurological de
suspected. 2
However, CT cannot exclude raised intracranial pressure (ICP).

Lumbar puncture

Lumbar puncture (LP) should be performed within one hour of hospital arrival before antibiotic treatment is commenced.
If performing an LP will delay antibiotic treatment, antibiotics should be given, and the LP should be performed afterwards.
Cerebrospinal culture is the gold standard investigation for diagnosing bacterial meningitis, and 90% of acute
bacterial meningitis cases have CSF WBC >100 cells/microlitre.
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CSF is analysed for cell count, gram stain (to identify bacteria), glucose, protein, lactate and the sample cultured. Other
investigations include bacterial and viral PCR.
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Contraindications
Contraindications to LP include\:
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Raised ICP (e.g. reduced consciousness, bradycardia and hypertension, focal neurological signs, abnormal posturing,
abnormal pupillary re
Shock
Extensive or spreading purpura
Convulsions (until stabilised)
Coagulation abnormalities (e.g. thrombocytopaenia, patient on anticoagulants)

Management

The approach to the management of meningitis can be divided into\:
2
Supportive treatments\:
Treatment of the causative organism
Treatment of complications\: metabolic disturbances, raised ICP and seizures
Meningitis is a noti
4
As always, follow local protocols to guide management.

Bacterial meningitis

All cases of suspected meningitis should be treated as bacterial until proven otherwise. Further management will then be
guided by the LP results.
Primary care
In primary care, the priority is urgent transfer to hospital.
If there is suspected meningococcal sepsis (with a non-blanching rash), then IM or IV benzylpenicillin can be given only if
this will not delay transfer (and the patient is not allergic).
Secondary care
In secondary care, initial empirical therapy includes\:
4
IV ceftriaxone\: for children 3 months and older and adults
IV cefotaxime and amoxicillin/ampicillin (L i s t e r i a cover)\: under 3 months old
IV dexamethasone\: for children >3 months with bacteria on gram stain, frankly purulent CSF, or CSF WBC >1000
cells/microlitre
Antibiotic therapy should be adjusted when the causative organism is con
Contacts
For con
antibiotics are usually cipro

Viral meningitis

For viral meningitis, treatment is mainly supportive.
IV aciclovir can be used if herpes simplex encephalitis is suspected.

Complications

Acute complications

These include sepsis and septic shock, disseminated intravascular coagulation, coma, cerebral oedema, raised intracranial
pressure, subdural eSIADH, seizures, peripheral gangrene and death.
2

Bacterial meningitis

30–50% of survivors of acute bacterial meningitis experience permanent neurological sequelae.
1
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Although overall mortality from acute bacterial meningitis has fallen in recent years, there has been no change in the rate
of complications.
1
Common complications include\:
1
Hearing loss (33.6%)
Seizures (12.6%)
Motor de
Cognitive impairment (9.1%)
Hydrocephalus (7.1%)
Visual disturbance (6.3%)
Appropriate follow-up should be arranged before discharge (review with a paediatrician at 4-6 weeks), and information
and support should be o

Viral meningitis

There is usually complete resolution within 10 days, although there may be longer-term sequelae, including headaches
and cognitive and psychological issues.
2

Prognosis

Meningitis is the leading infectious cause of death in children in the UK, but prognosis depends on the causative
pathogen as well as the patient's age, prior health and the severity of the illness.
2
Pneumococcal meningitis is associated with a poorer outcome than meningitis caused by N e i s s e r i a m e n i n g i t i d e s or
H a e m o p h i l u s i n
1
Most cases of viral meningitis are self-limiting with a good prognosis.
1

References

NICE CKS. M e n i n g i t i s - b a c t e r i a l m e n i n g i t i s a n d m e n i n g o c o c c a l d i s e a s e . Updated July 2019. Available from\: [LINK]
Patient.info. M e n i n g i t i s . Updated July 2019. Available from\: [LINK]
Figure 1. SVG by Mysid, original by SEER Development Team [1], Jmarchn. D i a g r a m o f m e n i n g e s . Licence\: [CC BY-SA]
Available from\: [LINK]
NICE. M e n i n g i t i s ( b a c t e r i a l ) a n d m e n i n g o c o c c a l s e p t i c a e m i a i n u n d e r 1 6 s \: r e c o gn i t i o n , d i a gn o s i s a n d m a n a g e m e n t .
Updated February 2015. Available from\: [LINK]
Public Health England. I n v a s i v e m e n i n g o c o c c a l d i s e a s e i n E n g l a n d \: a n n u a l l a b o r a t o r y-c o n
e p i d e m i o l o g i c a l y e a r 2 0 1 8 t o 2 0 1 9 . Published October 2019. Available from\: [LINK]
GOV.UK. C o m p l e t e r o u t i n e i m m u n i s a t i o n s c h e d u l e . Updated December 2019. Available from\: Van de Beek et al. C l i n i c a l f e a t u r e s a n d p r o g n o s t i c f a c t o r s i n a d u l t s w i t h b a c t e r i a l m e n i n gi t i s . [LINK]
March 2005. Available [LINK]
NICE. F e v e r i n u n d e r 5 s \: a s s e s s m e n t a n d i n i t i a l m a n a ge m e n t . November 2019. Available from\: [LINK]
Patient.info. L u m b a r P u n c t u r e . Updated October 2015. Available from\: [LINK]
from\:

Reviewer

Dr Laura Doherty
ST4 Paediatrics
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Contents

Introduction
Aetiology
Risk factors
Clinical features
Di
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