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

What is Neisseria meningitis?

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?

Answer 3

Meningococcal septicaemia refers to the meningococcus bacterial infection in the bloodstream. Meningococcal refers to the bacteria and septicaemia refers to infection in the blood stream. Meningococcal septicaemia is the cause of the classic non-blanching rash, indicating disseminated intravascular coagulopathy (DIC) and subcutaneous haemorrhages.

Question 4

What is meningococcal meningitis?

Answer 4

Meningococcal meningitis occurs when the bacteria infect the meninges and the cerebrospinal fluid around the brain and spinal cord.

Question 5

What is bacterial meningitis and its most common causes?

Answer 5

Bacterial meningitis is inflammation of the meninges caused by a bacterial infection. The most common causes 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

Group B strep (GBS) is the most common cause. GBS is usually contracted during birth from bacteria that live harmlessly in the mother’s vagina.

Question 7

What are the presentations of meningitis?

Answer 7

• fever
• neck stiffness
• vomiting
• headache
• photophobia
• altered consciousness
• seizures
• Where there ismeningococcal septicaemiachildren can present with anon-blanching rash.

Question 8

What are the signs of meningitis in neonates and babies?

Answer 8

Neonates and babies can present with verynon-specificsigns and symptoms, such as

• hypotonia
• poor feeding
• lethargy
• hypothermia
• abulging fontanelle.

Question 9

When do NICE recommend lumbar puncture?

Answer 9

• 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 are the two tests for meningeal irritation and how are they performed?

Answer 10

• Kernig’s testinvolves 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.
• Brudzinski’s testinvolves 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 11

What is the treatment for suspected meningitis in the community?

Answer 11

• Children seen in primary care with suspected meningitis and a non-blanching rash should receive an urgent stat injection of benzylpenicillin prior to transfer to hospital. - The dose will depend on their age, and giving antibiotics should not delay transfer.
• Where there is a true penicillin allergy, transfer should be the priority rather than finding alternative antibiotics.

Question 12

What is the treatment for bacterial meningitis in hospital?

Answer 12

• Under 3 months–cefotaximeplusamoxicillin(the amoxicillin is to coverlisteriacontracted during pregnancy)
• Above 3 months–*ceftriaxone
• Vancomycinshould be added to these antibiotics if there is a risk of penicillin resistant pneumococcal infection, for example recent foreign travel or prolonged antibiotic exposure.
• Steroidsare also used in bacterial meningitis to reduce the frequency and severity ofhearing lossandneurological damage.
• Dexamethasoneis given 4 times daily for 4 days to children over 3 months if the lumbar puncture is suggestive of bacterial meningitis

Question 13

What investigations are done in hospital for meningitis?

Answer 13

Investigations include blood culture and lumbar puncture Blood tests for meningococcal PCR should be sent if meningococcal disease is suspected.

Question 14

What conditions are bacterial meningitis and meningococcal disease?

Answer 14

Bacterial meningitis and meningococcal disease are notifiable diseases, so public health needs to be informed of all cases.

Question 15

Who is at increased risk if exposed to someone with a meningococcal infection?

Answer 15

• Significant exposure to a patient withmeningococcal infectionssuch 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 the7 daysprior 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.

Question 16

What is the treatment for contacts of meningococcal infection?

Answer 16

Post exposure prophylaxis is guided by public health, usually with a single dose of ciprofloxacin, ideally given within 24 hours of the initial diagnosis.

Question 17

What are the most common causes of viral meningitis?

Answer 17

Common causes of viral meningitis include herpes simplex virus (HSV), enterovirus, and varicella zoster virus (VZV).

Question 18

What investigation is needed if viral meningitis is suspected?

Answer 18

A sample of cerebrospinal fluid (CSF) from the lumbar puncture should be sent for viral PCR testing.

Question 19

What is 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

What is a lumbar puncture?

Answer 20

A lumbar puncture involves inserting a needle into the lower back to collect a sample of cerebrospinal fluid (CSF). The needle is usually inserted into the L3 – L4 intervertebral space. (spinal cord end at L1-L2 vertebral level)

Question 21

What samples are sent for during a lumbar puncture?

Answer 21

Samples are sent for bacterial culture, viral PCR, cell count, protein, and glucose A blood glucose sample should be sent at the same time for comparison with the CSF sample.

Question 22

How do CSF findings compare in bacterial and viral meningitis? Appearance, protein level, glucose, WCC, culture

Answer 22

Question 23

What are the complications of bacterial meningitis?

Answer 23

• Hearing lossis a key complication (why dexamethasone is given)
• Seizures and epilepsy
• Cognitive impairment and learning disability
• Memory loss
• Cerebral palsy, with focal neurological deficitssuch as limb weakness or spasticity