Meningitis

Question 1

What is meningitis?

Answer 1

Meningitis is defined as inflammation of the meninges. The meninges are the lining of the brain and spinal cord. This inflammation is usually due to a bacterial or viral infection.

Question 2

Briefly describe Neisseria meningitidis

Answer 2

Neisseria meningitidis is a gram-negative diplococcus bacteria. They are circular bacteria (cocci) that occur in pairs (diplo-). It is commonly known as meningococcus.

Question 3

What is meningococcal septicaemia?

Question 4

What is meningococcal meningitis?

Answer 4

Meningococcal meningitis is when the bacteria is infecting the meninges and the cerebrospinal fluid around the brain and spinal cord.

Question 5

What is the most common cause of bacterial meningitis in children and adults?

Answer 5

The most common causes of bacterial meningitis in children and adults are Neisseria meningitidis (meningococcus) and Streptococcus pneumoniae (pneumococcus).

Question 6

What is the most common cause of bacterial meningitis in neonates?

Answer 6

In neonates the most common cause is group B strep (GBS).

Question 7

How do neonates contract GBS?

Answer 7

GBS is usually contracted during birth from GBS bacteria that live harmlessly in the mother’s vagina.

Question 8

What are the clinical features of meningitis?

Answer 8

Typical symptoms of meningitis are fever, neck stiffness, vomiting, headache, photophobia, altered consciousness and seizures. Where there is meningococcal septicaemia children can present with a non-blanching rash. Other causes of bacterial meningitis do not usually cause the non-blanching rash.

Neonates and babies can present with very non-specific signs and symptoms, such as hypotonia, poor feeding, lethargy, hypothermia and a bulging fontanelle.

Question 9

When does NICE recommend a lumbar puncture in order to investigate meningitis?

Answer 9

NICE recommend a lumbar puncture as part of the investigations for all children:

• Under 1 month presenting with fever
• 1 to 3 months with fever and are unwell
• Under 1 year with unexplained fever and other features of serious illness

Question 10

What 2 tests are used to assess meningeal irritation?

Answer 10

There are two special tests you can perform to look for meningeal irritation:

• Kernig’s test
• Brudzinski’s test

Question 11

Briefly describe Kernig’s test

Answer 11

Kernig’s test involves lying the patient on their back, flexing one hip and knee to 90 degrees and then slowly straightening the knee whilst keeping the hip flexed at 90 degrees. This creates a slight stretch in the meninges. Where there is meningitis it will produce spinal pain or resistance to movement.

Question 12

Briefly describe Brudzinski’s test

Answer 12

Brudzinski’s test involves lying the patient flat on their back and gently using your hands to lift their head and neck off the bed and flex their chin to their chest. In a positive test this causes the patient to involuntarily flex their hips and knees.

Question 13

Briefly describe the management of bacterial meningitis in the community

Answer 13

Children seen in the primary care setting with suspected meningitis AND a non blanching rash should receive an urgent stat injection (IM or IV) of benzylpenicillin prior to transfer to hospital, as time is so important. The dose will depending on their age.

Giving antibiotics should not delay transfer to hospital. Where there is a true penicillin allergy, transfer should be the priority rather than finding alternative antibiotics.

Question 14

Briefly describe the management of bacterial meningitis in the hospital setting

Question 15

What antibiotics are given for bacterial meningitis in patients under 3 months and above 3 months?

Answer 15

Under 3 months: cefotaxime plus amoxicillin (the amoxicillin is to cover listeria contracted during pregnancy).

Above 3 months: ceftriaxone.

Question 16

Is bacterial meningitis a notifiable disease?

Answer 16

Bacteria meningitis and meningococcal infection are notifiable diseases, so public health need to be informed of all cases.

Question 17

Briefly describe the post-exposure rationale for meningiococcal infections

Answer 17

Significant exposure to a patient with meningococcal infections such as meningitis or septicaemia puts people at risk of contracting the illness. This risk is highest for people that have had close prolonged contact within the 7 days prior to the onset of the illness. The risk decreases 7 days after exposure. Therefore, if no symptoms have developed 7 days after exposure they are unlikely to develop the illness.

Post exposure prophylaxis is guided by public health. The usual antibiotic choice for this is a single dose of ciprofloxacin. It should be given as soon as possible and ideally within 24 hours of the initial diagnosis.

Question 18

What viruses cause meningitis?

Answer 18

The most common causes of viral meningitis are herpes simplex virus (HSV), enterovirus and varicella zoster virus (VZV). A sample of the CSF from the lumbar puncture should be sent forviral PCR testing.

Question 19

Briefly describe the management of viral meningitis

Answer 19

Viral meningitis tends to be milder than bacterial and often only requires supportive treatment. Aciclovir can be used to treat suspected or confirmed HSV or VZV infection.

Question 20

Briefly describe the role of lumbar puncture in diagnosing meningitis

Answer 20

A lumbar puncture involves inserting a needle into the lower back to collect a sample of cerebrospinal fluid (CSF). The spinal cord ends at the L1-L2 vertebral level, so the needle is usually inserted into the L3-L4 intervertebral space. Samples are sent for bacterial culture, viral PCR, cell count, protein and glucose. A blood glucose sample should be sent at the same time so that it can be compared to the CSF sample. The samples need to be sent immediately.

Question 21

Briefly differentiate between the CSF of bacterial and viral meningitis

Note: appearance, protein, glucose, white cell count and culture

Answer 21

Question 22

What are the complications of meningitis?

Answer 22

• Hearing loss is a key complication
• Seizures and epilepsy
• Cognitive impairment and learning disability
• Memory loss
• Cerebral palsy, with focal neurological deficits such as limb weakness or spasticity